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1.
Ann Biomed Eng ; 52(8): 1941-1954, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38652384

RESUMEN

There are numerous effective procedures for cell signaling, in which humans directly transmit detectable signals to cells to govern their essential behaviors. From a biomedical perspective, the cellular response to the combined influence of electrical and magnetic fields holds significant promise in various domains, such as cancer treatment, targeted drug delivery, gene therapy, and wound healing. Among these modern cell signaling methods, electromagnetic fields (EMFs) play a pivotal role; however, there remains a paucity of knowledge concerning the effects of EMFs across all wavelengths. It's worth noting that most wavelengths are incompatible with human cells, and as such, this study excludes them from consideration. In this review, we aim to comprehensively explore the most effective and current EMFs, along with their therapeutic impacts on various cell types. Specifically, we delve into the influence of alternating electromagnetic fields (AEMFs) on diverse cell behaviors, encompassing proliferation, differentiation, biomineralization, cell death, and cell migration. Our findings underscore the substantial potential of these pivotal cellular behaviors in advancing the treatment of numerous diseases. Moreover, AEMFs wield a significant role in the realms of biomaterials and tissue engineering, given their capacity to decisively influence biomaterials, facilitate non-invasive procedures, ensure biocompatibility, and exhibit substantial efficacy. It is worth mentioning that AEMFs often serve as a last-resort treatment option for various diseases. Much about electromagnetic fields remains a mystery to the scientific community, and we have yet to unravel the precise mechanisms through which wavelengths control cellular fate. Consequently, our understanding and knowledge in this domain predominantly stem from repeated experiments yielding similar effects. In the ensuing sections of this article, we delve deeper into our extended experiments and research.


Asunto(s)
Campos Electromagnéticos , Humanos , Animales , Movimiento Celular , Proliferación Celular , Diferenciación Celular
2.
Front Microbiol ; 15: 1321059, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38371938

RESUMEN

Catalytic activity of microbial communities maintains the services and functions of soils. Microbial communities require energy and carbon for microbial growth, which they obtain by transforming organic matter (OM), oxidizing a fraction of it and transferring the electrons to various terminal acceptors. Quantifying the relations between matter and energy fluxes is possible when key parameters such as reaction enthalpy (∆rH), energy use efficiency (related to enthalpy) (EUE), carbon use efficiency (CUE), calorespirometric ratio (CR), carbon dioxide evolution rate (CER), and the apparent specific growth rate (µapp) are known. However, the determination of these parameters suffers from unsatisfying accuracy at the technical (sample size, instrument sensitivity), experimental (sample aeration) and data processing levels thus affecting the precise quantification of relationships between carbon and energy fluxes. To address these questions under controlled conditions, we analyzed microbial turnover processes in a model soil amended using a readily metabolizable substrate (glucose) and three commercial isothermal microcalorimeters (MC-Cal/100P, TAM Air and TAM III) with different sample sizes meaning varying volume-related thermal detection limits (LODv) (0.05-1mW L-1). We conducted aeration experiments (aerated and un-aerated calorimetric ampoules) to investigate the influence of oxygen limitation and thermal perturbation on the measurement signal. We monitored the CER by measuring the additional heat caused by CO2 absorption using a NaOH solution acting as a CO2 trap. The range of errors associated with the calorimetrically derived µapp, EUE, and CR was determined and compared with the requirements for quantifying CUE and the degree of anaerobicity (ηA). Calorimetrically derived µapp and EUE were independent of the instrument used. However, instruments with a low LODv yielded the most accurate results. Opening and closing the ampoules for oxygen and CO2 exchange did not significantly affect metabolic heats. However, regular opening during calorimetrically derived CER measurements caused significant measuring errors due to strong thermal perturbation of the measurement signal. Comparisons between experimentally determined CR, CUE,ηA, and modeling indicate that the evaluation of CR should be performed with caution.

3.
Microb Risk Anal ; 24: 100263, 2023 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-37234934

RESUMEN

From the perspectives of molecular biology, genetics and biothermodynamics, SARS-CoV-2 is the among the best characterized viruses. Research on SARS-CoV-2 has shed a new light onto driving forces and molecular mechanisms of viral evolution. This paper reports results on empirical formulas, biosynthesis reactions and thermodynamic properties of biosynthesis (multiplication) for the Zeta P.2, Eta B.1.525, Theta P.3, Kappa B.1.617.1, Iota B.1.526, Lambda C.37 and Mu B.1.621 variants of SARS-CoV-2. Thermodynamic analysis has shown that the physical driving forces for evolution of SARS-CoV-2 are Gibbs energy of biosynthesis and Gibbs energy of binding. The driving forces have led SARS-CoV-2 through the evolution process from the original Hu-1 to the newest variants in accordance with the expectations of the evolution theory.

4.
Curr Oncol ; 30(2): 1924-1944, 2023 02 05.
Artículo en Inglés | MEDLINE | ID: mdl-36826111

RESUMEN

As per a recent study conducted by the WHO, 15.4% of all cancers are caused by infectious agents of various categories, and more than 10% of them are attributed to viruses. The emergence of COVID-19 has once again diverted the scientific community's attention toward viral diseases. Some researchers have postulated that SARS-CoV-2 will add its name to the growing list of oncogenic viruses in the long run. However, owing to the complexities in carcinogenesis of viral origin, researchers across the world are struggling to identify the common thread that runs across different oncogenic viruses. Classical pathways of viral oncogenesis have identified oncogenic mediators in oncogenic viruses, but these mediators have been reported to act on diverse cellular and multiple omics pathways. In addition to viral mediators of carcinogenesis, researchers have identified various host factors responsible for viral carcinogenesis. Henceforth owing to viral and host complexities in viral carcinogenesis, a singular mechanistic pathway remains yet to be established; hence there is an urgent need to integrate concepts from system biology, cancer microenvironment, evolutionary perspective, and thermodynamics to understand the role of viruses as drivers of cancer. In the present manuscript, we provide a holistic view of the pathogenic pathways involved in viral oncogenesis with special emphasis on alteration in the tumor microenvironment, genomic alteration, biological entropy, evolutionary selection, and host determinants involved in the pathogenesis of viral tumor genesis. These concepts can provide important insight into viral cancers, which can have an important implication for developing novel, effective, and personalized therapeutic options for treating viral cancers.


Asunto(s)
COVID-19 , Neoplasias , Humanos , SARS-CoV-2 , Virus Oncogénicos , Neoplasias/genética , Carcinogénesis , Genómica , Microambiente Tumoral
5.
Microbiol Res ; 270: 127337, 2023 May.
Artículo en Inglés | MEDLINE | ID: mdl-36804126

RESUMEN

The SARS-CoV-2 Hydra with many heads (variants) has been causing the COVID-19 pandemic for 3 years. The appearance of every new head (SARS-CoV-2 variant) causes a new pandemic wave. The last in the series is the XBB.1.5 "Kraken" variant. In the general public (social media) and in the scientific community (scientific journals), during the last several weeks since the variant has appeared, the question was raised of whether the infectivity of the new variant will be greater. This article attempts to provide the answer. Analysis of thermodynamic driving forces of binding and biosynthesis leads to the conclusion that infectivity of the XBB.1.5 variant could be increased to a certain extent. The pathogenicity of the XBB.1.5 variant seems to be unchanged compared to the other Omicron variants.


Asunto(s)
COVID-19 , SARS-CoV-2 , Humanos , Pandemias
6.
Microorganisms ; 10(8)2022 Aug 19.
Artículo en Inglés | MEDLINE | ID: mdl-36014092

RESUMEN

In the present study, we investigated whether a non-invasive metabolic heat flux analysis could serve the determination of the functional traits in free-living saprotrophic decomposer fungi and aid the prediction of fungal influences on ecosystem processes. For this, seven fungi, including ascomycete, basidiomycete, and zygomycete species, were investigated in a standardised laboratory environment, employing wheat straw as a globally relevant lignocellulosic substrate. Our study demonstrates that biocalorimetry can be employed successfully to determine growth-related fungal activity parameters, such as apparent maximum growth rates (AMGR), cultivation times until the observable onset of fungal growth at AMGR (tAMGR), quotients formed from the AMGR and tAMGR (herein referred to as competitive growth potential, CGP), and heat yield coefficients (YQ/X), the latter indicating the degree of resource investment into fungal biomass versus other functional attributes. These parameters seem suitable to link fungal potentials for biomass production to corresponding ecological strategies employed during resource utilisation, and therefore may be considered as fungal life history traits. A close connection exists between the CGP and YQ/X values, which suggests an interpretation that relates to fungal life history strategies.

7.
J Biomol Struct Dyn ; 40(19): 8905-8912, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-33988066

RESUMEN

We propose a unique theoretical methodology because of the global high priority rating to search for the repurposed drugs that outfit clinical suitability to SARS-CoV-2. The approach is based on the exploration of structural analysis, computation of biothermodynamics, interactions and the prediction of entropy sign successively via molecular dynamics. We tested this methodology for Favipiravir/Dolutegravir drugs on the apo form of SARS-CoV-2 main protease. This theoretical exploration not only suggested the presence of strong interactions between (SARS-CoV-2 + Favipiravir/Dolutegravir) but also emphasized the clinical suitability of Favipiravir over Dolutegravir to treat SARS-CoV-2 main protease. The supremacy of Favipiravir over Doultegravir is well supported by the results of global clinical trials on SARS-CoV-2 infection. Thus, this work will pave the way for incremental advancement towards future design and development of more specific inhibitors to treat SARS-CoV-2 infection in humans.Communicated by Ramaswamy H. Sarma.


Asunto(s)
COVID-19 , SARS-CoV-2 , Humanos , Pirazinas , Amidas , Simulación del Acoplamiento Molecular , Inhibidores de Proteasas , Simulación de Dinámica Molecular
8.
Microorganisms ; 9(10)2021 Sep 29.
Artículo en Inglés | MEDLINE | ID: mdl-34683381

RESUMEN

Biological, physical and chemical interaction between one (or more) microorganisms and a host organism, causing host cell damage, represents an infection. Infection of a plant, animal or microorganism with a virus can prevent infection with another virus. This phenomenon is known as viral interference. Viral interference is shown to result from two types of interactions, one taking place at the cell surface and the other intracellularly. Various viruses use different receptors to enter the same host cell, but various strains of one virus use the same receptor. The rate of virus-receptor binding can vary between different viruses attacking the same host, allowing interference or coinfection. The outcome of the virus-virus-host competition is determined by the Gibbs energies of binding and growth of the competing viruses and host. The virus with a more negative Gibbs energy of binding to the host cell receptor will enter the host first, while the virus characterized by a more negative Gibbs energy of growth will overtake the host metabolic machine and dominate. Once in the host cell, the multiplication machinery is shared by the competing viruses. Their potential to utilize it depends on the Gibbs energy of growth. Thus, the virus with a more negative Gibbs energy of growth will dominate. Therefore, the outcome can be interference or coinfection, depending on both the attachment kinetics (susceptibility) and the intracellular multiplication machinery (permittivity). The ratios of the Gibbs energies of binding and growth of the competing viruses determine the outcome of the competition. Based on this, a predictive model of virus-virus competition is proposed.

9.
Front Plant Sci ; 12: 671868, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34135926

RESUMEN

Elemental composition of Gossypium hirsutum L. (cotton), Oryza sativa L. (Asian rice), Phaseolus vulgaris L. (common bean), Saccharum spp. L. (sugarcane), and Zea mays L. (corn) was used to calculate their empirical formulas (unit carbon formulas) and growth stoichiometry. The empirical formulas were used to find standard enthalpy of formation, standard molar entropy, standard Gibbs energy of formation, and standard molar heat capacity. A comparison was made between thermodynamic properties of live matter of the analyzed plants and other unicellular and multicellular organisms. Moreover, the growth process was analyzed through standard enthalpy, entropy, and Gibbs energy of biosynthesis. The average standard Gibbs energy of biosynthesis was found to be +463.0 kJ/C-mol. Thus, photosynthesis provides energy and carbon for plant growth. The average intercepted photosynthetic energy was found to be 15.5 MJ/C-mol for the analyzed plants. However, due to inefficiency, a great fraction of the intercepted photosynthetic energy cannot be used by plants. The average usable photosynthetic energy was found to be -2.3 MJ/C-mol. The average thermodynamic driving force for growth is -1.9 MJ/C-mol. Driving forces of growth of C3 and C4 plants were compared. It was found that C4 plants have a greater driving force of growth than C3 plants, which reflects the greater efficiency of C4 photosynthesis. The relationship between the driving force and growth rates was analyzed by determining phenomenological L coefficients. The determined phenomenological coefficients span two orders of magnitude, depending on plant species and environmental conditions. The L coefficient of P. vulgaris was found to be lower than that of other plants, due to additional energy requirements of nitrogen fixation.

10.
Adv Protein Chem Struct Biol ; 126: 227-278, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34090616

RESUMEN

Proteins have evolved in specific 3D structures and play different functions in cells and determine various reactions and pathways. The newly synthesized amino acid chains once depart ribosome must crumple into three-dimensional structures so can be biologically active. This process of protein that makes a functional molecule is called protein folding. The protein folding is both a biological and a physicochemical process that depends on the sequence of it. In fact, this process occurs more complicated and in some cases and in exposure to some molecules like glucose (glycation), mistaken folding leads to amyloid structures and fatal disorders called conformational diseases. Such conditions are detected by the quality control system of the cell and these abnormal proteins undergo renovation or degradation. This scenario takes place by the chaperones, chaperonins, and Ubiquitin-proteasome complex. Understanding of protein folding mechanisms from different views including experimental and computational approaches has revealed some intermediate ensembles such as molten globule and has been subjected to biophysical and molecular biology attempts to know more about prevalent conformational diseases.


Asunto(s)
Amiloide , Desplegamiento Proteico , Proteolisis , Deficiencias en la Proteostasis/metabolismo , Amiloide/química , Amiloide/metabolismo , Glicosilación , Humanos , Chaperonas Moleculares/metabolismo , Complejo de la Endopetidasa Proteasomal/metabolismo , Ubiquitina/metabolismo
11.
Sci Total Environ ; 773: 145111, 2021 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-33940717

RESUMEN

Plastics are globally used for a variety of benefits. As a consequence of poor recycling or reuse, improperly disposed plastic waste accumulates in terrestrial and aquatic ecosystems to a considerable extent. Large plastic waste items become fragmented to small particles through mechanical and (photo)chemical processes. Particles with sizes ranging from millimeter (microplastics, <5 mm) to nanometer (nanoplastics, NP, <100 nm) are apparently persistent and have adverse effects on ecosystems and human health. Current research therefore focuses on whether and to what extent microorganisms or enzymes can degrade these NP. In this study, we addressed the question of what information isothermal titration calorimetry, which tracks the heat of reaction of the chain scission of a polyester, can provide about the kinetics and completeness of the degradation process. The majority of the heat represents the cleavage energy of the ester bonds in polymer backbones providing real-time kinetic information. Calorimetry operates even in complex matrices. Using the example of the cutinase-catalyzed degradation of polyethylene terephthalate (PET) nanoparticles, we found that calorimetry (isothermal titration calorimetry-ITC) in combination with thermokinetic models is excellently suited for an in-depth analysis of the degradation processes of NP. For instance, we can separately quantify i) the enthalpy of surface adsorption ∆AdsH = 129 ± 2 kJ mol-1, ii) the enthalpy of the cleavage of the ester bonds ∆EBH = -58 ± 1.9 kJ mol-1 and the apparent equilibrium constant of the enzyme substrate complex K = 0.046 ± 0.015 g L-1. It could be determined that the heat production of PET NP degradation depends to 95% on the reaction heat and only to 5% on the adsorption heat. The fact that the percentage of cleaved ester bonds (η = 12.9 ± 2.4%) is quantifiable with the new method is of particular practical importance. The new method promises a quantification of enzymatic and microbial adsorption to NP and their degradation in mimicked real-world aquatic conditions.


Asunto(s)
Microplásticos , Tereftalatos Polietilenos , Calorimetría , Ecosistema , Humanos , Plásticos
12.
Entropy (Basel) ; 22(7)2020 Jul 16.
Artículo en Inglés | MEDLINE | ID: mdl-33286546

RESUMEN

From a thermodynamic point of view, living cell life is no more than a cyclic process. It starts with the newly separated daughter cells and restarts when the next generations grow as free entities. During this cycle, the cell changes its entropy. In cancer, the growth control is damaged. In this paper, we analyze the role of the volume-area ratio in the cell in relation to the heat exchange between cell and its environment in order to point out its effect on cancer growth. The result holds to a possible control of the cancer growth based on the heat exchanged by the cancer toward its environment and the membrane potential variation, with the consequence of controlling the ions fluxes and the related biochemical reactions. This second law approach could represent a starting point for a possible future support for the anticancer therapies, in order to improve their effectiveness for the untreatable cancers.

13.
Int J Mol Sci ; 21(21)2020 Nov 06.
Artículo en Inglés | MEDLINE | ID: mdl-33172189

RESUMEN

In systems biology, material balances, kinetic models, and thermodynamic boundary conditions are increasingly used for metabolic network analysis. It is remarkable that the reversibility of enzyme-catalyzed reactions and the influence of cytosolic conditions are often neglected in kinetic models. In fact, enzyme-catalyzed reactions in numerous metabolic pathways such as in glycolysis are often reversible, i.e., they only proceed until an equilibrium state is reached and not until the substrate is completely consumed. Here, we propose the use of irreversible thermodynamics to describe the kinetic approximation to the equilibrium state in a consistent way with very few adjustable parameters. Using a flux-force approach allowed describing the influence of cytosolic conditions on the kinetics by only one single parameter. The approach was applied to reaction steps 2 and 9 of glycolysis (i.e., the phosphoglucose isomerase reaction from glucose 6-phosphate to fructose 6-phosphate and the enolase-catalyzed reaction from 2-phosphoglycerate to phosphoenolpyruvate and water). The temperature dependence of the kinetic parameter fulfills the Arrhenius relation and the derived activation energies are plausible. All the data obtained in this work were measured efficiently and accurately by means of isothermal titration calorimetry (ITC). The combination of calorimetric monitoring with simple flux-force relations has the potential for adequate consideration of cytosolic conditions in a simple manner.


Asunto(s)
Calorimetría/métodos , Glucólisis/fisiología , Redes y Vías Metabólicas/fisiología , Catálisis , Glucólisis/genética , Cinética , Biología de Sistemas/métodos , Temperatura , Termodinámica
14.
Int J Mol Sci ; 21(21)2020 Oct 25.
Artículo en Inglés | MEDLINE | ID: mdl-33113841

RESUMEN

For systems biology, it is important to describe the kinetic and thermodynamic properties of enzyme-catalyzed reactions and reaction cascades quantitatively under conditions prevailing in the cytoplasm. While in part I kinetic models based on irreversible thermodynamics were tested, here in part II, the influence of the presumably most important cytosolic factors was investigated using two glycolytic reactions (i.e., the phosphoglucose isomerase reaction (PGI) with a uni-uni-mechanism and the enolase reaction with an uni-bi-mechanism) as examples. Crowding by macromolecules was simulated using polyethylene glycol (PEG) and bovine serum albumin (BSA). The reactions were monitored calorimetrically and the equilibrium concentrations were evaluated using the equation of state ePC-SAFT. The pH and the crowding agents had the greatest influence on the reaction enthalpy change. Two kinetic models based on irreversible thermodynamics (i.e., single parameter flux-force and two-parameter Noor model) were applied to investigate the influence of cytosolic conditions. The flux-force model describes the influence of cytosolic conditions on reaction kinetics best. Concentrations of magnesium ions and crowding agents had the greatest influence, while temperature and pH-value had a medium influence on the kinetic parameters. With this contribution, we show that the interplay of thermodynamic modeling and calorimetric process monitoring allows a fast and reliable quantification of the influence of cytosolic conditions on kinetic and thermodynamic parameters.


Asunto(s)
Algoritmos , Citosol/metabolismo , Glucosa-6-Fosfato Isomerasa/metabolismo , Glucólisis , Modelos Teóricos , Fosfopiruvato Hidratasa/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Animales , Biocatálisis , Bovinos , Concentración de Iones de Hidrógeno , Cinética , Magnesio/metabolismo , Polietilenglicoles/metabolismo , Albúmina Sérica Bovina/metabolismo , Temperatura , Termodinámica
15.
R Soc Open Sci ; 7(7): 200299, 2020 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-32874627

RESUMEN

The fight against a multifaceted incurable disease such as cancer requires a multidisciplinary approach to overcome the multitude of molecular defects at its origin. Here, a new thermophysical biochemical approach has been suggested and associated with the use of electromagnetic fields to control the growth of cancer cells. In particular, thermodynamic analysis of the heat transfer is developed in correlation with cellular parameters such as the volume/area ratio. We propose that the electromagnetic wave, at the specific frequency calculated as the characteristic response time of any cell type to the external thermal perturbation, can affect resonant intracellular molecular oscillations. The biochemical model hypothesizes that microtubules are stabilized, and the impact is predicted on cell growth, migration and mitochondrial activity. Experimental validation of the theoretical results shows that the thermodynamic analysis allows the application of the specific electromagnetic field able to decrease cancer cell invasion and proliferation.

16.
Biochim Biophys Acta Gen Subj ; 1864(10): 129675, 2020 10.
Artículo en Inglés | MEDLINE | ID: mdl-32610157

RESUMEN

BACKGROUND: Thermodynamic methods are finding more and more applications in systems biology, which attempts to understand cell functions mechanistically. Unfortunately, the state variables used (reaction enthalpy and Gibbs energy) do not take sufficient account of the conditions inside of cells, especially the crowding with macromolecules. METHODS: For this reason, the influence of crowding agents and various other parameters such as salt concentrations, pH and temperature on equilibrium position and reaction enthalpy of the glycolytic example reaction 9 (2-Phospoglycerate - > Phosphoenolpyruvate + H2O) was investigated. The conditions were chosen to be as close as possible to the cytosolic conditions. Poly(ethylene glycol) MW = 20,000 g mol-1 (PEG 20,000) was used to analyze the influence of crowding with macromolecules. The equation of state electrolyte Perturbed-Chain Statistical Associating Fluid Theory (ePC-SAFT) was applied to consider the influence of crowding agents on the reaction equilibria. RESULTS AND CONCLUSIONS: For the reaction enthalpies and for the equilibria, it was found that the influence of salts and temperature is not pronounced while that of pH and PEG 20,000 concentration is considerable. Furthermore, it could be shown that under identical measurement conditions there are no differences between the van 't Hoff and the calorimetrically determined reaction enthalpy. GENERAL SIGNIFICANCE: The results show how important it is to consider the special cytosolic conditions when applying thermodynamic data in systems biology.


Asunto(s)
Citosol/metabolismo , Fosfopiruvato Hidratasa/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/metabolismo , Calorimetría , Glucólisis , Termodinámica
17.
Biotechnol Biofuels ; 13: 59, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32231709

RESUMEN

BACKGROUND: Ethanol production through fermentation of gas mixtures containing CO, CO2 and H2 has just started operating at commercial scale. However, quantitative schemes for understanding and predicting productivities, yields, mass transfer rates, gas flow profiles and detailed energy requirements have been lacking in literature; such are invaluable tools for process improvements and better systems design. The present study describes the construction of a hybrid model for simulating ethanol production inside a 700 m3 bubble column bioreactor fed with gas of two possible compositions, i.e., pure CO and a 3:1 mixture of H2 and CO2. RESULTS: Estimations made using the thermodynamics-based black-box model of microbial reactions on substrate threshold concentrations, biomass yields, as well as CO and H2 maximum specific uptake rates agreed reasonably well with data and observations reported in literature. According to the bioreactor simulation, there is a strong dependency of process performance on mass transfer rates. When mass transfer coefficients were estimated using a model developed from oxygen transfer to water, ethanol productivity reached 5.1 g L-1 h-1; when the H2/CO2 mixture is fed to the bioreactor, productivity of CO fermentation was 19% lower. Gas utilization reached 23 and 17% for H2/CO2 and CO fermentations, respectively. If mass transfer coefficients were 100% higher than those estimated, ethanol productivity and gas utilization may reach 9.4 g L-1 h-1 and 38% when feeding the H2/CO2 mixture at the same process conditions. The largest energetic requirements for a complete manufacturing plant were identified for gas compression and ethanol distillation, being higher for CO fermentation due to the production of CO2. CONCLUSIONS: The thermodynamics-based black-box model of microbial reactions may be used to quantitatively assess and consolidate the diversity of reported data on CO, CO2 and H2 threshold concentrations, biomass yields, maximum substrate uptake rates, and half-saturation constants for CO and H2 for syngas fermentations by acetogenic bacteria. The maximization of ethanol productivity in the bioreactor may come with a cost: low gas utilization. Exploiting the model flexibility, multi-objective optimizations of bioreactor performance might reveal how process conditions and configurations could be adjusted to guide further process development.

18.
Lasers Med Sci ; 34(2): 239-246, 2019 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-29959633

RESUMEN

Curcumin and salicylic acid are both phenolic compounds and they can both affect cancer treatment efficacy. In this study, the effects of methylene blue-curcumin (CU-MB) and methylene blue-salicylic acid (SA-MB) ion pair complexes on MDA-MB-231 human breast cancer cells are studied. According to the thermodynamic parameters, the stability of curcumin and salicylic acid complexes ion pair complexes was compared. The free energy of ion pair interactions was calculated based on binding constants. A comparison of the free energies of the complexes (CU-MB: ∆G°b1 = - 21.11 kJ/mol and ∆G°b2 = - 8.37 kJ/mol, SA-MB: ∆G°b1 = - 12.92 kJ/mol and ∆G°b2 = - 9.02 kJ/mol) indicates that the interaction of methylene blue in first binding interaction with curcumin is greater than that of methylene blue with salicylic acid. Electrostatic interactions are the main forces in the binding of both compounds to methylene blue. All forces are inter-molecular physical interactions. The results of cellular experiments show that ion pairing has enhanced the reduction of cell viability. By increasing molecular stability and prevention of dimerization of methylene blue, the cell killing potential of methylene blue increases and it subsequently causes enhancement of photodynamic efficacy.


Asunto(s)
Neoplasias de la Mama/patología , Curcumina/farmacología , Azul de Metileno/farmacología , Fenoles/farmacología , Fotoquimioterapia , Ácido Salicílico/farmacología , Apoptosis/efectos de los fármacos , Muerte Celular/efectos de los fármacos , Muerte Celular/efectos de la radiación , Línea Celular Tumoral , Forma de la Célula/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Supervivencia Celular/efectos de la radiación , Femenino , Humanos , Iones , Luz , Fármacos Fotosensibilizantes/farmacología , Análisis Espectral , Termodinámica
19.
Annu Rev Chem Biomol Eng ; 7: 395-414, 2016 Jun 07.
Artículo en Inglés | MEDLINE | ID: mdl-27276551

RESUMEN

Thermodynamic principles have been applied to enzyme-catalyzed reactions since the beginning of the 1930s in an attempt to understand metabolic pathways. Currently, thermodynamics is also applied to the design and analysis of biotechnological processes. The key thermodynamic quantity is the Gibbs energy of reaction, which must be negative for a reaction to occur spontaneously. However, the application of thermodynamic feasibility studies sometimes yields positive Gibbs energies of reaction even for reactions that are known to occur spontaneously, such as glycolysis. This article reviews the application of thermodynamics in enzyme-catalyzed reactions. It summarizes the basic thermodynamic relationships used for describing the Gibbs energy of reaction and also refers to the nonuniform application of these relationships in the literature. The review summarizes state-of-the-art approaches that describe the influence of temperature, pH, electrolytes, solvents, and concentrations of reacting agents on the Gibbs energy of reaction and, therefore, on the feasibility and yield of biological reactions.


Asunto(s)
Enzimas/metabolismo , Biocatálisis , Electrólitos/química , Enzimas/química , Concentración de Iones de Hidrógeno , Cinética , Solventes/química , Temperatura , Termodinámica
20.
J Biomol Tech ; 21(4): 167-93, 2010 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-21119929

RESUMEN

This paper reviews the best-known differential scanning calorimetries (DSCs), such as conventional DSC, microelectromechanical systems-DSC, infrared-heated DSC, modulated-temperature DSC, gas flow-modulated DSC, parallel-nano DSC, pressure perturbation calorimetry, self-reference DSC, and high-performance DSC. Also, we describe here the most extensive applications of DSC in biology and nanoscience.


Asunto(s)
Rastreo Diferencial de Calorimetría/métodos , Nanoestructuras/química , Termodinámica , Cristalización/métodos , Microscopía Electrónica de Rastreo , Nanotecnología , Temperatura
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