This study focuses on post-harvest pest management in agriculture, in particular the transition to modified atmospheres as a sustainable alternative to conventional pesticide methods. Using Computational Fluid Dynamics (CFD) simulations, we analysed the dynamics of oxygen distribution within a pest control chamber. We tested four different configurations of nitrogen inlet and outlet positions to determine the most effective setup. The simulations used the twoLiquidMixingFoam solver in OpenFOAM to model gas mixing and diffusion. Our results show that the configuration with the nitrogen inlet at the top and the outlet at the bottom (Case D) was the most efficient. This configuration reached the target oxygen concentration of 1.5% in 4.4 h, significantly faster than the other configurations. These results highlight the importance of inlet and outlet positioning in improving the efficiency of oxygen reduction and ensuring a consistent low oxygen level throughout the chamber. Optimising the placement of nitrogen inlets and outlets has significant potential to improve the effectiveness of modified atmosphere treatments for pest control. Future research should consider additional environmental factors, different storage conditions and insect mortality models to further refine these methods.
{"title":"Improving the Oxygen Removal Process in a Chamber Using Computational Fluid Dynamics Simulations for Pest Control Applications","authors":"E. Kaloudis","doi":"10.3390/oxygen4030017","DOIUrl":"https://doi.org/10.3390/oxygen4030017","url":null,"abstract":"This study focuses on post-harvest pest management in agriculture, in particular the transition to modified atmospheres as a sustainable alternative to conventional pesticide methods. Using Computational Fluid Dynamics (CFD) simulations, we analysed the dynamics of oxygen distribution within a pest control chamber. We tested four different configurations of nitrogen inlet and outlet positions to determine the most effective setup. The simulations used the twoLiquidMixingFoam solver in OpenFOAM to model gas mixing and diffusion. Our results show that the configuration with the nitrogen inlet at the top and the outlet at the bottom (Case D) was the most efficient. This configuration reached the target oxygen concentration of 1.5% in 4.4 h, significantly faster than the other configurations. These results highlight the importance of inlet and outlet positioning in improving the efficiency of oxygen reduction and ensuring a consistent low oxygen level throughout the chamber. Optimising the placement of nitrogen inlets and outlets has significant potential to improve the effectiveness of modified atmosphere treatments for pest control. Future research should consider additional environmental factors, different storage conditions and insect mortality models to further refine these methods.","PeriodicalId":516952,"journal":{"name":"Oxygen","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141813555","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Lower limb muscle fatigue is the main reason for withdrawal from diving. Therefore, this study aimed to determine the local muscle oxygen saturation and hemoglobin concentration in the vastus lateralis muscle during different freediving disciplines. One freediver participated in this study, and his chronological age was 40 years, body mass 75.0 kg, body height 184.0 cm, and body fat 13.7%. The participant has been practicing freediving for 6 years. The variables in this study included anthropometric indices, heart rate, and muscle oxygen dynamics parameters (SmO2 (oxygen muscle saturation) and tHb (total hemoglobin)). The variables were measured during five diving disciplines: static apnea, bifin, dynamic no fins (DNF), monofin, and sneaking. Measurements were performed during intensive training/competition during the diving season in August 2023. The results of this study showed that when oxygen starts to decrease during the dive, the tHb increases. Furthermore, the times at which maximal tHb and minimal SmO2 were achieved are also shown. These parameters occurred at almost the same time across all disciplines: static (SmO2, 142; tHb, 150 s), bifin (SmO2, 153; tHb, 148 s), DNF (SmO2, 162; tHb, 178 s), monofin (SmO2, 96; tHb, 94 s), and sneaking (SmO2, 212; tHb, 228 s). Also, differences in tHb and SmO2 were present between diving disciplines. In particular, the highest increase in tHb was present in bifin (0.0028 AU/s), whereas monofin showed a decrease (−0.0009 AU/s). On the other hand, the highest desaturation was seen in bifin (−0.87%/s) and the lowest in sneaking (−0.29%/s) These findings emphasize the physiological characteristics of freedivers engaging in different freediving disciplines that influence muscles during the dive. Such responses could be observed through a concurrent hypoxia/hypercapnia and a transient reduction in the Fahraeus effect.
{"title":"Muscular Oxygen Saturation and Hemoglobin Concentration during Freediving: A Case Study","authors":"Dario Vrdoljak, Ž. Dujić, Nikola Foretić","doi":"10.3390/oxygen4030016","DOIUrl":"https://doi.org/10.3390/oxygen4030016","url":null,"abstract":"Lower limb muscle fatigue is the main reason for withdrawal from diving. Therefore, this study aimed to determine the local muscle oxygen saturation and hemoglobin concentration in the vastus lateralis muscle during different freediving disciplines. One freediver participated in this study, and his chronological age was 40 years, body mass 75.0 kg, body height 184.0 cm, and body fat 13.7%. The participant has been practicing freediving for 6 years. The variables in this study included anthropometric indices, heart rate, and muscle oxygen dynamics parameters (SmO2 (oxygen muscle saturation) and tHb (total hemoglobin)). The variables were measured during five diving disciplines: static apnea, bifin, dynamic no fins (DNF), monofin, and sneaking. Measurements were performed during intensive training/competition during the diving season in August 2023. The results of this study showed that when oxygen starts to decrease during the dive, the tHb increases. Furthermore, the times at which maximal tHb and minimal SmO2 were achieved are also shown. These parameters occurred at almost the same time across all disciplines: static (SmO2, 142; tHb, 150 s), bifin (SmO2, 153; tHb, 148 s), DNF (SmO2, 162; tHb, 178 s), monofin (SmO2, 96; tHb, 94 s), and sneaking (SmO2, 212; tHb, 228 s). Also, differences in tHb and SmO2 were present between diving disciplines. In particular, the highest increase in tHb was present in bifin (0.0028 AU/s), whereas monofin showed a decrease (−0.0009 AU/s). On the other hand, the highest desaturation was seen in bifin (−0.87%/s) and the lowest in sneaking (−0.29%/s) These findings emphasize the physiological characteristics of freedivers engaging in different freediving disciplines that influence muscles during the dive. Such responses could be observed through a concurrent hypoxia/hypercapnia and a transient reduction in the Fahraeus effect.","PeriodicalId":516952,"journal":{"name":"Oxygen","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141830908","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Liquid organic hydrogen carriers (LOHCs) are aromatic molecules that are being considered for the safe storage and release of hydrogen. The thermodynamic properties of a range of aromatic ethers were investigated using various experimental and theoretical methods to assess their suitability as LOHC materials. The absolute vapour pressures were measured for benzyl phenyl ether, dibenzyl ether and 2-methoxynaphthalene using the transpiration method. The standard molar enthalpies and entropies of vaporisation/sublimation were derived from the temperature dependence of the vapour pressures. The combustion energies of benzyl phenyl ether and dibenzyl ether were measured using high-precision combustion calorimetry, and their standard molar enthalpies of formation were derived from these data. High-level quantum chemical calculations were used to calculate the standard molar enthalpies of formation in the gas phase for benzyl phenyl ether, dibenzyl ether and 2-methoxynaphthalene. The latter values agreed very well with the experimental results obtained in this work. The thermodynamic properties of the hydrogenation/dehydrogenation reactions in liquid phase in LOHC systems based on methoxy–benzene, diphenyl ether, benzyl phenyl ether, dibenzyl ether and 2-methoxynaphthalene were derived and compared with the data for similarly structured hydrogen carriers based on benzene, diphenylmethane, 1,2-diphenylethane, 1,3-diphenylpropane and naphthalene. The influence of the oxygen functionality on the thermodynamic properties of the hydrogenation/dehydrogenation reactions was evaluated.
{"title":"Does the Oxygen Functionality Really Improve the Thermodynamics of Reversible Hydrogen Storage with Liquid Organic Hydrogen Carriers?","authors":"S. P. Verevkin, A. Samarov, Sergey V. Vostrikov","doi":"10.3390/oxygen4030015","DOIUrl":"https://doi.org/10.3390/oxygen4030015","url":null,"abstract":"Liquid organic hydrogen carriers (LOHCs) are aromatic molecules that are being considered for the safe storage and release of hydrogen. The thermodynamic properties of a range of aromatic ethers were investigated using various experimental and theoretical methods to assess their suitability as LOHC materials. The absolute vapour pressures were measured for benzyl phenyl ether, dibenzyl ether and 2-methoxynaphthalene using the transpiration method. The standard molar enthalpies and entropies of vaporisation/sublimation were derived from the temperature dependence of the vapour pressures. The combustion energies of benzyl phenyl ether and dibenzyl ether were measured using high-precision combustion calorimetry, and their standard molar enthalpies of formation were derived from these data. High-level quantum chemical calculations were used to calculate the standard molar enthalpies of formation in the gas phase for benzyl phenyl ether, dibenzyl ether and 2-methoxynaphthalene. The latter values agreed very well with the experimental results obtained in this work. The thermodynamic properties of the hydrogenation/dehydrogenation reactions in liquid phase in LOHC systems based on methoxy–benzene, diphenyl ether, benzyl phenyl ether, dibenzyl ether and 2-methoxynaphthalene were derived and compared with the data for similarly structured hydrogen carriers based on benzene, diphenylmethane, 1,2-diphenylethane, 1,3-diphenylpropane and naphthalene. The influence of the oxygen functionality on the thermodynamic properties of the hydrogenation/dehydrogenation reactions was evaluated.","PeriodicalId":516952,"journal":{"name":"Oxygen","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141687471","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This review explores the unique structural and functional characteristics of natural products featuring highly oxygenated cyclobutane rings, with a specific focus on oxetane and 1,2-dioxetane motifs. It presents the structures and biological activities of compounds containing these rings, highlighting their contribution to molecular stability and pharmacological potency. Through detailed case studies and recent research findings, it has been demonstrated that these oxygen-rich rings enhance the molecular diversity and biological efficacy of natural products, potentially offering new avenues for drug development. Notably, these compounds are predominantly synthesized by microorganisms and can also be found in extracts from fungi, plants, and certain marine invertebrates. Compounds with oxetane and 1,2-dioxetane rings are primarily noted for their strong antineoplastic properties, among other biological activities. In contrast, most 1,2-dioxetanes exhibit potent antiprotozoal effects. It is important to note that 1,2-dioxetanes often serve as intermediate products in oxidation reactions, characterized by their instability and propensity to decompose into new compounds.
{"title":"Highly Oxygenated Cyclobutane Ring in Biomolecules: Insights into Structure and Activity","authors":"Valery M. Dembitsky","doi":"10.3390/oxygen4020012","DOIUrl":"https://doi.org/10.3390/oxygen4020012","url":null,"abstract":"This review explores the unique structural and functional characteristics of natural products featuring highly oxygenated cyclobutane rings, with a specific focus on oxetane and 1,2-dioxetane motifs. It presents the structures and biological activities of compounds containing these rings, highlighting their contribution to molecular stability and pharmacological potency. Through detailed case studies and recent research findings, it has been demonstrated that these oxygen-rich rings enhance the molecular diversity and biological efficacy of natural products, potentially offering new avenues for drug development. Notably, these compounds are predominantly synthesized by microorganisms and can also be found in extracts from fungi, plants, and certain marine invertebrates. Compounds with oxetane and 1,2-dioxetane rings are primarily noted for their strong antineoplastic properties, among other biological activities. In contrast, most 1,2-dioxetanes exhibit potent antiprotozoal effects. It is important to note that 1,2-dioxetanes often serve as intermediate products in oxidation reactions, characterized by their instability and propensity to decompose into new compounds.","PeriodicalId":516952,"journal":{"name":"Oxygen","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141111825","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
I. Ferreira, Ana Rita C. Duarte, M. Diniz, Ricardo Salgado
Halophyte plants and seaweed are described in the literature as rich sources of antioxidant compounds that can be used in the pharmaceutical and food industries. In this work, we studied the antioxidant composition of five species of halophytic plants (Suaeda vera Forssk, Portulaca oleracea L., Inula crithmoides L., Salicornia ramosissima (Hook.f.) J. Woods and Sarcocornia perennis (Mill.) A.J.Scott) and three seaweeds (Gracilaria gracilis (Stackhouse) Steentoft, L.Irvine and Farnham, Fucus spiralis L. and Ulva rigida C. Agardh) collected in Sado Estuary, Portugal. In the case of the plants, different parts of the plant were also assessed. Various extraction procedures were also performed to understand which methods were most suitable for extracting the various antioxidant compounds. Therefore, the aim of this study was to characterize the antioxidant compounds in halophytes and seaweed using various methods (ABTS, DPPH and FRAP), as well as the phenolic (TPC) and flavonoid (TFC) contents in the different extracts obtained. The amount of soluble protein in each extract was also determined. The results show that methanolic extracts generally have a higher antioxidant capacity, while the highest soluble protein content was observed in aqueous extracts. The seaweed Fucus Spiralis showed the highest antioxidant content, while in halophytic plants the highest antioxidant content was detected in the leaves. In general, this work confirms the potential of halophytes and seaweed as sources of antioxidant compounds for use in the food and pharmaceutical industries.
据文献记载，盐生植物和海藻是抗氧化化合物的丰富来源，可用于制药和食品工业。在这项工作中，我们研究了五种卤叶植物（Suaeda vera Forssk、Portulaca oleracea L.、Inula crithmoides L.、Salicornia ramosissima (Hook.f. J.)、Salicornia ramosissima (Hook.f. J.)和Salicornia ramosissima (Hook.f. J.)）的抗氧化成分、Salicornia ramosissima (Hook.f.) J. Woods 和 Sarcocornia perennis (Mill.) A.J.Scott）以及在葡萄牙萨多河口采集的三种海藻（Gracilaria gracilis (Stackhouse) Steentoft, L.Irvine and Farnham, Fucus spiralis L. 和 Ulva rigida C. Agardh）的抗氧化成分。对植物的不同部位也进行了评估。此外，还进行了各种萃取程序，以了解哪种方法最适合萃取各种抗氧化化合物。因此，本研究的目的是利用各种方法（ABTS、DPPH 和 FRAP）鉴定卤叶植物和海藻中的抗氧化化合物，以及不同提取物中的酚类（TPC）和类黄酮（TFC）含量。此外，还测定了每种提取物中可溶性蛋白质的含量。结果表明，甲醇提取物通常具有较高的抗氧化能力，而水提取物中的可溶性蛋白质含量最高。海藻 Fucus Spiralis 的抗氧化剂含量最高，而在盐生植物中，叶片的抗氧化剂含量最高。总之，这项研究证实了卤叶植物和海藻作为抗氧化化合物来源的潜力，可用于食品和制药行业。
{"title":"Unveiling the Antioxidant Potential of Halophyte Plants and Seaweeds for Health Applications","authors":"I. Ferreira, Ana Rita C. Duarte, M. Diniz, Ricardo Salgado","doi":"10.3390/oxygen4020011","DOIUrl":"https://doi.org/10.3390/oxygen4020011","url":null,"abstract":"Halophyte plants and seaweed are described in the literature as rich sources of antioxidant compounds that can be used in the pharmaceutical and food industries. In this work, we studied the antioxidant composition of five species of halophytic plants (Suaeda vera Forssk, Portulaca oleracea L., Inula crithmoides L., Salicornia ramosissima (Hook.f.) J. Woods and Sarcocornia perennis (Mill.) A.J.Scott) and three seaweeds (Gracilaria gracilis (Stackhouse) Steentoft, L.Irvine and Farnham, Fucus spiralis L. and Ulva rigida C. Agardh) collected in Sado Estuary, Portugal. In the case of the plants, different parts of the plant were also assessed. Various extraction procedures were also performed to understand which methods were most suitable for extracting the various antioxidant compounds. Therefore, the aim of this study was to characterize the antioxidant compounds in halophytes and seaweed using various methods (ABTS, DPPH and FRAP), as well as the phenolic (TPC) and flavonoid (TFC) contents in the different extracts obtained. The amount of soluble protein in each extract was also determined. The results show that methanolic extracts generally have a higher antioxidant capacity, while the highest soluble protein content was observed in aqueous extracts. The seaweed Fucus Spiralis showed the highest antioxidant content, while in halophytic plants the highest antioxidant content was detected in the leaves. In general, this work confirms the potential of halophytes and seaweed as sources of antioxidant compounds for use in the food and pharmaceutical industries.","PeriodicalId":516952,"journal":{"name":"Oxygen","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140991927","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Raphaël Serreau, A. Amirouche, A. Benyamina, Sabine Berteina-Raboin
In this review, in addition to the potential cardiovascular applications of β-blockers and, more specifically, propranolol, we wanted to list the more recent applications in psychiatry as well as current knowledge on the impact of oxidative stress on propranolol hydrochloride and the oxidative stress that could be limited by the latter. In fact, a number of studies show that this molecule is modified by oxidative stress but is also able to limit it. Mention is also made to studies on the increasingly important problem of eliminating drug waste and its impact on the environment, particularly the marine environment. Given the increase in the consumption of medicines, more rigorous waste management is needed to avoid impacting biodiversity.
{"title":"Propranolol Hydrochloride Psychiatric Effectiveness and Oxidative Stress: An Update","authors":"Raphaël Serreau, A. Amirouche, A. Benyamina, Sabine Berteina-Raboin","doi":"10.3390/oxygen4020009","DOIUrl":"https://doi.org/10.3390/oxygen4020009","url":null,"abstract":"In this review, in addition to the potential cardiovascular applications of β-blockers and, more specifically, propranolol, we wanted to list the more recent applications in psychiatry as well as current knowledge on the impact of oxidative stress on propranolol hydrochloride and the oxidative stress that could be limited by the latter. In fact, a number of studies show that this molecule is modified by oxidative stress but is also able to limit it. Mention is also made to studies on the increasingly important problem of eliminating drug waste and its impact on the environment, particularly the marine environment. Given the increase in the consumption of medicines, more rigorous waste management is needed to avoid impacting biodiversity.","PeriodicalId":516952,"journal":{"name":"Oxygen","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140671693","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
David Mantle, Hannah Rowbottom, Jacob Jones, Indiia Margarita Potts, Nadia Turton, Mollie Dewsbury, Guillermo López-Lluch, Iain P Hargreaves
The generation of energy within cells is a fundamental process enabling cell survival, and as such it represents a potential target in cancer therapy. In this article, we therefore review the relative contributions of glycolysis and oxidative phosphorylation/mitochondrial function to cancer cell energy generation, and we highlight their respective potential value as chemotherapeutic targets. This article is particularly focussed on the potential role of coenzyme Q10 in the prevention and treatment of cancer.
{"title":"Energy Metabolism as a Therapeutic Target in Cancer: The Role of Coenzyme Q10","authors":"David Mantle, Hannah Rowbottom, Jacob Jones, Indiia Margarita Potts, Nadia Turton, Mollie Dewsbury, Guillermo López-Lluch, Iain P Hargreaves","doi":"10.3390/oxygen4020008","DOIUrl":"https://doi.org/10.3390/oxygen4020008","url":null,"abstract":"The generation of energy within cells is a fundamental process enabling cell survival, and as such it represents a potential target in cancer therapy. In this article, we therefore review the relative contributions of glycolysis and oxidative phosphorylation/mitochondrial function to cancer cell energy generation, and we highlight their respective potential value as chemotherapeutic targets. This article is particularly focussed on the potential role of coenzyme Q10 in the prevention and treatment of cancer.","PeriodicalId":516952,"journal":{"name":"Oxygen","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140716351","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Oxygen (O2) was discovered approximately 250 years ago (Contribution 1), a breakthrough accredited to at least three people: Antoine-Laurent de Lavoisier in France (Antoine Lavoisier), Carl Wilhelm Scheele in Sweden, and Joseph Priestley in England [...]
氧气（O2）发现于大约 250 年前（贡献 1），这一突破至少归功于三个人：这一突破至少归功于三个人：法国的安托万-拉瓦锡（Antoine Lavoisier）、瑞典的卡尔-威廉-舍勒（Carl Wilhelm Scheele）和英国的约瑟夫-普里斯特利（Joseph Priestley） [...]
{"title":"Oxygen: Highlights from the Papers Published in the Journal up to February 2024","authors":"John T. Hancock","doi":"10.3390/oxygen4010007","DOIUrl":"https://doi.org/10.3390/oxygen4010007","url":null,"abstract":"Oxygen (O2) was discovered approximately 250 years ago (Contribution 1), a breakthrough accredited to at least three people: Antoine-Laurent de Lavoisier in France (Antoine Lavoisier), Carl Wilhelm Scheele in Sweden, and Joseph Priestley in England [...]","PeriodicalId":516952,"journal":{"name":"Oxygen","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140244257","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
D. Palaiogiannis, V. Athanasiadis, Theodoros G. Chatzimitakos, Martha Mantiniotou, Eleni Bozinou, D. Makris, S. Lalas
The objective of this study was to determine the optimal conditions for the recovery of bioactive and antioxidant compounds in aqueous solutions of Cistus creticus leaves and then employ the optimal extract for the enrichment of yogurt samples. The optimal conditions were established by a response surface methodology and were determined to be a liquid-to-solid ratio of 48 mL/g at 76 °C for 41 min. The optimum extract yielded TPC 157.17 mg GAE/g dw and TFC 2.38 mg QE/g dw, while FRAP and DPPH values were 1258.52 and 933.67 μmol AAE/g dw, respectively. HPLC‒DAD was utilized to identify and quantify specific polyphenols, like myricetin rhamnoside, in the extract. The optimal extract was then added to yogurt desserts during their preparation at three different concentrations to study how the physicochemical characteristics of the yogurt, as well as the antioxidant capacity added during enrichment, were affected. Statistical analysis of the results was carried out in order to obtain more valid data. It seems that the most suitable concentration for yogurt fortification was 0.1% w/v of the extract as, at this concentration, the yogurts exhibited higher antioxidant capacity, and their physicochemical characteristics were improved.
{"title":"Extraction of Bioactive Compounds from Cistus creticus Leaves and Their Use in the Preparation of Yogurt Desserts","authors":"D. Palaiogiannis, V. Athanasiadis, Theodoros G. Chatzimitakos, Martha Mantiniotou, Eleni Bozinou, D. Makris, S. Lalas","doi":"10.3390/oxygen4010005","DOIUrl":"https://doi.org/10.3390/oxygen4010005","url":null,"abstract":"The objective of this study was to determine the optimal conditions for the recovery of bioactive and antioxidant compounds in aqueous solutions of Cistus creticus leaves and then employ the optimal extract for the enrichment of yogurt samples. The optimal conditions were established by a response surface methodology and were determined to be a liquid-to-solid ratio of 48 mL/g at 76 °C for 41 min. The optimum extract yielded TPC 157.17 mg GAE/g dw and TFC 2.38 mg QE/g dw, while FRAP and DPPH values were 1258.52 and 933.67 μmol AAE/g dw, respectively. HPLC‒DAD was utilized to identify and quantify specific polyphenols, like myricetin rhamnoside, in the extract. The optimal extract was then added to yogurt desserts during their preparation at three different concentrations to study how the physicochemical characteristics of the yogurt, as well as the antioxidant capacity added during enrichment, were affected. Statistical analysis of the results was carried out in order to obtain more valid data. It seems that the most suitable concentration for yogurt fortification was 0.1% w/v of the extract as, at this concentration, the yogurts exhibited higher antioxidant capacity, and their physicochemical characteristics were improved.","PeriodicalId":516952,"journal":{"name":"Oxygen","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139895019","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
On the thirty-fifth anniversary of the first description of O2-sensitive K+ channels in the carotid body chemoreceptors O2 sensing remains a salient issue in the literature. Whereas much has been learned about this subject, important questions such as the identity of the specific K+ channel subtype(s) responsible for O2 sensing by chemoreceptors and the mechanism(s) by which their activities are altered by hypoxia have not yet been definitively answered. O2 sensing is a fundamental biological process necessary for the acute and chronic responses to varying environmental O2 levels which allow organisms to adapt to hypoxia. Whereas chronic responses depend on the modulation of hypoxia-inducible transcription factors which determine the expression of numerous genes encoding enzymes, transporters and growth factors, acute responses rely mainly on the dynamic modulation of ion channels by hypoxia, causing adaptive changes in cell excitability, contractility and secretory activity in specialized tissues. The most widely studied oxygen-sensitive ion channels are potassium channels, but oxygen sensing by members of both the calcium and sodium channel families has also been demonstrated. Given the explosion of information on this topic, in this review, we will focus on the mechanisms of physiological oxygen chemotransduction by PO2-dependent K+ channels, with particular emphasis on their function in carotid body chemoreceptor cells (CBCC) and pulmonary artery smooth muscle cells (PASMC), highlighting areas of consensus and controversy within the field. We will first describe the most well-established concepts, those reproduced in multiple laboratories, and then discuss selected observations or questions that remain unresolved, and that limit our progress in this field.
{"title":"The Thirty-Fifth Anniversary of K+ Channels in O2 Sensing: What We Know and What We Don’t Know","authors":"Asuncion Rocher, Philip I. Aaronson","doi":"10.3390/oxygen4010004","DOIUrl":"https://doi.org/10.3390/oxygen4010004","url":null,"abstract":"On the thirty-fifth anniversary of the first description of O2-sensitive K+ channels in the carotid body chemoreceptors O2 sensing remains a salient issue in the literature. Whereas much has been learned about this subject, important questions such as the identity of the specific K+ channel subtype(s) responsible for O2 sensing by chemoreceptors and the mechanism(s) by which their activities are altered by hypoxia have not yet been definitively answered. O2 sensing is a fundamental biological process necessary for the acute and chronic responses to varying environmental O2 levels which allow organisms to adapt to hypoxia. Whereas chronic responses depend on the modulation of hypoxia-inducible transcription factors which determine the expression of numerous genes encoding enzymes, transporters and growth factors, acute responses rely mainly on the dynamic modulation of ion channels by hypoxia, causing adaptive changes in cell excitability, contractility and secretory activity in specialized tissues. The most widely studied oxygen-sensitive ion channels are potassium channels, but oxygen sensing by members of both the calcium and sodium channel families has also been demonstrated. Given the explosion of information on this topic, in this review, we will focus on the mechanisms of physiological oxygen chemotransduction by PO2-dependent K+ channels, with particular emphasis on their function in carotid body chemoreceptor cells (CBCC) and pulmonary artery smooth muscle cells (PASMC), highlighting areas of consensus and controversy within the field. We will first describe the most well-established concepts, those reproduced in multiple laboratories, and then discuss selected observations or questions that remain unresolved, and that limit our progress in this field.","PeriodicalId":516952,"journal":{"name":"Oxygen","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-02-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139895416","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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