Morteza Mollazadeh, A. Fakhari, T. Mortezazadeh, F. B. Mofrad, Ali Jamali Nazarie
In this study, a new nano-structure, N,P-doped graphene quantum dots (N,P-GQDs), were synthesized as multipurpose imaging agent for performing scintigraphy and magnetic resonance imaging (MRI). Some standard characterization methods were used to identify the nano-structure. In vitro cytotoxicity evaluation using MTT assay revealed that N,P-GQDs nanoparticles had no significant cytotoxicity after 24 and 48 h against normal (MCF-10A) and cancerous (MCF 7) human breast cell line in concentration up to 200 μg/mL. The N,P-GQDs were radiolabeled with Technetium-99m as 99mTc-(N,P-GQDs) and the radiochemical purity was assayed by ITLC concluding RCP ≥ 95 %. The passing of 99mTc-(N,P-GQDs) through 0.1 µm filter demonstrated that 70.8 % of particles were <0.1 µm. In order to perform scintigraphy, the 99mTc-(N,P-GQDs) were injected to female healthy Wistar rats. The results showed that the radio-complex was captured and eliminated just by kidneys. Moreover, in vitro T1-weighted phantom MRI imaging showed that the N,P-GQDs have proper relaxivity in comparison to Dotarem® as a clinically available contrast agent. The results showed that the N,P-GQDs have potential to be considered as a novel and encouraging agent for both molecular MRI and nuclear medicine imagings.
{"title":"Synthesis, MTT assay, 99m-Technetium radiolabeling, biodistribution evaluation of radiotracer and in vitro magnetic resonance imaging study of P,N-doped graphene quantum dots as a new multipurpose imaging nano-agent","authors":"Morteza Mollazadeh, A. Fakhari, T. Mortezazadeh, F. B. Mofrad, Ali Jamali Nazarie","doi":"10.1515/ract-2023-0180","DOIUrl":"https://doi.org/10.1515/ract-2023-0180","url":null,"abstract":"\u0000 In this study, a new nano-structure, N,P-doped graphene quantum dots (N,P-GQDs), were synthesized as multipurpose imaging agent for performing scintigraphy and magnetic resonance imaging (MRI). Some standard characterization methods were used to identify the nano-structure. In vitro cytotoxicity evaluation using MTT assay revealed that N,P-GQDs nanoparticles had no significant cytotoxicity after 24 and 48 h against normal (MCF-10A) and cancerous (MCF 7) human breast cell line in concentration up to 200 μg/mL. The N,P-GQDs were radiolabeled with Technetium-99m as 99mTc-(N,P-GQDs) and the radiochemical purity was assayed by ITLC concluding RCP ≥ 95 %. The passing of 99mTc-(N,P-GQDs) through 0.1 µm filter demonstrated that 70.8 % of particles were <0.1 µm. In order to perform scintigraphy, the 99mTc-(N,P-GQDs) were injected to female healthy Wistar rats. The results showed that the radio-complex was captured and eliminated just by kidneys. Moreover, in vitro T1-weighted phantom MRI imaging showed that the N,P-GQDs have proper relaxivity in comparison to Dotarem® as a clinically available contrast agent. The results showed that the N,P-GQDs have potential to be considered as a novel and encouraging agent for both molecular MRI and nuclear medicine imagings.","PeriodicalId":21167,"journal":{"name":"Radiochimica Acta","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2024-05-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141099969","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Erik C. Abbott, Logan D. Gibb, Cody A. Nizinski, Elijah W. Allen, Hiram E. E. O’Connor, Luther W. McDonald IV
An important challenge in utilizing particle morphology in nuclear forensic or fuel fabrication applications is understanding why differences in morphologies are observed following varying processing conditions. This is often due to competition and interplay between thermodynamic and kinetic influences. To that end, some of the kinetic influences in the uranyl peroxide precipitation reaction were evaluated and compared to thermodynamic influences studied previously. Metastudtite (UO2O2·2H2O) was synthesized from solutions of uranyl nitrate or chloride, and the reaction time was varied from 100 s to 230 min enabling an evaluation of kinetic and thermodynamic influences. The metastudtite was then calcined to U3O8, and all materials were analyzed by powder X-ray diffraction (p-XRD) and scanning electron microscopy (SEM). Analysis by p-XRD confirmed the sample purity of metastudtite and U3O8. SEM images were analyzed using the Morphological Analysis for Materials (MAMA) software to measure the size and shape of the nanoparticles for a statistical comparison between materials. Metastudtite produced at shorter reaction times exhibited a kinetically controlled shape by forming smaller and rounder particles than metastudtite produced at longer reaction times. Metastudtite produced at the longer reaction times exhibited differences between the uranyl nitrate and uranyl chloride routes with the nitrate exhibiting a more angular and faceted morphology than the chloride. Overall, the control of the supersaturation ratio (S) played a significant role in determining the morphology of the metastudtite. Morphological differences between the U3O8 confirmed the role of nanoparticle agglomeration in forming larger sintered particles. The results help demonstrate the importance of understanding particle formation mechanisms in the long-term development of morphology in nuclear forensics or in developing advanced fuels with specific characteristics.
在核鉴识或燃料制造应用中利用颗粒形态学的一个重要挑战是了解在不同加工条件下观察到形态差异的原因。这通常是由于热力学和动力学影响之间的竞争和相互作用造成的。为此，我们对过氧化铀沉淀反应中的一些动力学影响因素进行了评估，并与之前研究的热力学影响因素进行了比较。从硝酸铀酰或氯化物溶液中合成了偏闪石（UO2O2-2H2O），反应时间从 100 秒到 230 分钟不等，从而对动力学和热力学的影响进行了评估。然后将偏闪石煅烧为八氧化三铀，并通过粉末 X 射线衍射（p-XRD）和扫描电子显微镜（SEM）对所有材料进行分析。粉末 X 射线衍射分析证实了偏闪长岩和八氧化三铀样品的纯度。使用材料形态分析（MAMA）软件对扫描电子显微镜图像进行了分析，以测量纳米颗粒的大小和形状，从而对不同材料进行统计比较。与反应时间较长的偏闪长岩相比，反应时间较短的偏闪长岩形成的颗粒更小、更圆，从而呈现出受动力学控制的形状。用较长的反应时间制备的偏闪长岩在硝酸铀和氯化铀路线上表现出差异，硝酸铀比氯化铀表现出更多的棱角和切面形态。总之，过饱和比（S）的控制在决定偏闪长岩的形态方面起着重要作用。八氧化三铀之间的形态差异证实了纳米颗粒团聚在形成较大烧结颗粒中的作用。这些结果有助于证明，在核鉴识或开发具有特定特性的先进燃料时，了解颗粒形成机制对形态的长期发展具有重要意义。
{"title":"Kinetic evaluation of the uranyl peroxide synthetic route on morphology","authors":"Erik C. Abbott, Logan D. Gibb, Cody A. Nizinski, Elijah W. Allen, Hiram E. E. O’Connor, Luther W. McDonald IV","doi":"10.1515/ract-2024-0277","DOIUrl":"https://doi.org/10.1515/ract-2024-0277","url":null,"abstract":"\u0000 An important challenge in utilizing particle morphology in nuclear forensic or fuel fabrication applications is understanding why differences in morphologies are observed following varying processing conditions. This is often due to competition and interplay between thermodynamic and kinetic influences. To that end, some of the kinetic influences in the uranyl peroxide precipitation reaction were evaluated and compared to thermodynamic influences studied previously. Metastudtite (UO2O2·2H2O) was synthesized from solutions of uranyl nitrate or chloride, and the reaction time was varied from 100 s to 230 min enabling an evaluation of kinetic and thermodynamic influences. The metastudtite was then calcined to U3O8, and all materials were analyzed by powder X-ray diffraction (p-XRD) and scanning electron microscopy (SEM). Analysis by p-XRD confirmed the sample purity of metastudtite and U3O8. SEM images were analyzed using the Morphological Analysis for Materials (MAMA) software to measure the size and shape of the nanoparticles for a statistical comparison between materials. Metastudtite produced at shorter reaction times exhibited a kinetically controlled shape by forming smaller and rounder particles than metastudtite produced at longer reaction times. Metastudtite produced at the longer reaction times exhibited differences between the uranyl nitrate and uranyl chloride routes with the nitrate exhibiting a more angular and faceted morphology than the chloride. Overall, the control of the supersaturation ratio (S) played a significant role in determining the morphology of the metastudtite. Morphological differences between the U3O8 confirmed the role of nanoparticle agglomeration in forming larger sintered particles. The results help demonstrate the importance of understanding particle formation mechanisms in the long-term development of morphology in nuclear forensics or in developing advanced fuels with specific characteristics.","PeriodicalId":21167,"journal":{"name":"Radiochimica Acta","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2024-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140968343","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Radioactive radium (Ra) mainly comes from the mining and milling of uranium and other metal or non-metal mines, phosphate production and fertilizer use, production of oil and gas, coal combustion, wastewater treatment, and various wastes from the above activities, which is ubiquitous in the environment. Phytoremediation is a green and cheap remediation technology for metal/radionuclide-contaminated sites. Radium is often of particular interest and there are many literatures on parameters of Ra concentration in plants and transfer factors from soil to plant from a radiological impact assessment point of view. However, review articles on phytoremediation of Ra-polluted soil are relatively few. This review focused on radium-polluted soil phytoremediation, involving two main strategies of phytoextraction and phytostabilization, which covered the potential (hyper)accumulators for Ra, characteristics of Ra uptake from soil by plants, influencing factors, and phytostabilization application. In future research works, more attention should be paid to the deep insights and mechanism researches of Ra uptake/immobilization by plants. This review will deepen the understanding of the relationship of radium-soil-plants, and to enhance the potential application of phytoremediation as an alternative treatment technology for remediation of Ra-polluted soil site.
{"title":"Phytoremediation of radium contaminated soils: recent advances and prospects","authors":"Jianlong Wang, Can Chen","doi":"10.1515/ract-2023-0248","DOIUrl":"https://doi.org/10.1515/ract-2023-0248","url":null,"abstract":"Radioactive radium (Ra) mainly comes from the mining and milling of uranium and other metal or non-metal mines, phosphate production and fertilizer use, production of oil and gas, coal combustion, wastewater treatment, and various wastes from the above activities, which is ubiquitous in the environment. Phytoremediation is a green and cheap remediation technology for metal/radionuclide-contaminated sites. Radium is often of particular interest and there are many literatures on parameters of Ra concentration in plants and transfer factors from soil to plant from a radiological impact assessment point of view. However, review articles on phytoremediation of Ra-polluted soil are relatively few. This review focused on radium-polluted soil phytoremediation, involving two main strategies of phytoextraction and phytostabilization, which covered the potential (hyper)accumulators for Ra, characteristics of Ra uptake from soil by plants, influencing factors, and phytostabilization application. In future research works, more attention should be paid to the deep insights and mechanism researches of Ra uptake/immobilization by plants. This review will deepen the understanding of the relationship of radium-soil-plants, and to enhance the potential application of phytoremediation as an alternative treatment technology for remediation of Ra-polluted soil site.","PeriodicalId":21167,"journal":{"name":"Radiochimica Acta","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2024-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140938131","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A mechanistic modelling of the adsorption processes onto individual minerals presenting in the near- and far-fields can greatly enhance the credibility of long-term safety assessments of granite-based geological repositories. In this study, the titration and U(VI) adsorption characteristics of chlorite, one of the major minerals of rock fractures, have been studied. Potentiometric titration curves at two ionic strengths (0.1 and 0.4 mol/L NaCl) are successfully interpreted by considering protonation/deprotonation reactions on generic edge sites (≡SOH) in the framework of a non-electrostatic surface complexation model (SCM). The adsorption of U(VI) on chlorite was reached after 24 h, the adsorption kinetics can be described by a pseudo-second-order model. A non-electrostatic SCM with three surface complexes (≡SOUO2+, ≡SO(UO2)3(OH)5 and ≡SO(UO2)3(OH)72−) was set up based on pH edges of U(VI) at adsorption equilibrium in the absence of CO2. Additional, experimental data measured as a function of U(VI) concentration, solid-to-liquid ratio and carbonate concentration were well reproduced by the proposed model. Finally, parallel experiments were conducted using X-ray photoelectron spectroscopy (XPS) to analyze the variation of U(VI) surface species speciation at different pH values. The good agreement between SCM prediction and XPS analysis demonstrates the reliability of the model in predicting and quantifying the radionuclides retention by chlorite.
{"title":"The adsorption of U(VI) on chlorite: batch, modeling and XPS study","authors":"Qiang Jin, Yuxiong Wang, Xin Zhao, Ye Fan, Xinya Diao, Zongyuan Chen, Zhijun Guo","doi":"10.1515/ract-2024-0278","DOIUrl":"https://doi.org/10.1515/ract-2024-0278","url":null,"abstract":"A mechanistic modelling of the adsorption processes onto individual minerals presenting in the near- and far-fields can greatly enhance the credibility of long-term safety assessments of granite-based geological repositories. In this study, the titration and U(VI) adsorption characteristics of chlorite, one of the major minerals of rock fractures, have been studied. Potentiometric titration curves at two ionic strengths (0.1 and 0.4 mol/L NaCl) are successfully interpreted by considering protonation/deprotonation reactions on generic edge sites (≡SOH) in the framework of a non-electrostatic surface complexation model (SCM). The adsorption of U(VI) on chlorite was reached after 24 h, the adsorption kinetics can be described by a pseudo-second-order model. A non-electrostatic SCM with three surface complexes (≡SOUO<jats:sub>2</jats:sub> <jats:sup>+</jats:sup>, ≡SO(UO<jats:sub>2</jats:sub>)<jats:sub>3</jats:sub>(OH)<jats:sub>5</jats:sub> and ≡SO(UO<jats:sub>2</jats:sub>)<jats:sub>3</jats:sub>(OH)<jats:sub>7</jats:sub> <jats:sup>2−</jats:sup>) was set up based on pH edges of U(VI) at adsorption equilibrium in the absence of CO<jats:sub>2</jats:sub>. Additional, experimental data measured as a function of U(VI) concentration, solid-to-liquid ratio and carbonate concentration were well reproduced by the proposed model. Finally, parallel experiments were conducted using X-ray photoelectron spectroscopy (XPS) to analyze the variation of U(VI) surface species speciation at different pH values. The good agreement between SCM prediction and XPS analysis demonstrates the reliability of the model in predicting and quantifying the radionuclides retention by chlorite.","PeriodicalId":21167,"journal":{"name":"Radiochimica Acta","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2024-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140937955","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In proton therapy, the protons are used to destroy the cancer cells efficiently at the Bragg peak without much damage to normal cells. The protons can also produce neutrons, protons, and high-energy gamma rays through nuclear reactions with cancerous and healthy tissues as well as with beamline components. The effective observed dose in the therapy is enhanced due to the interaction of nuclear particles with cancerous tissues. Such nuclear particles can have several effects on drugs used in immunotherapy, such as immunotherapy in combination with proton therapy, which has been used to treat cancer. In the present investigations, the gamma, neutron, and protons interaction parameters of some immunotherapy drugs, such as dostarlimab, atezolizumab, ipilimumab, nivolumab, and pembrolizumab, are determined by using EpiXs, NGCal, and PSTAR software. It is found that the EBF and EABF for all selected immunotherapy drugs increase with increasing penetration depth, peaking at 100 keV. The peaking is more symmetric at a higher penetration depth of 40 mfp than at a lower one of 1 mfp. At lower energies of gamma photons, the EBF values increase exponentially, and at higher energies, they increase linearly with increasing penetration depth for all selected drugs. Mass attenuation factors are slightly higher for thermal neutrons than for fast neutrons for selected immunotherapeutic drugs, indicating that thermal neutrons more actively participate in these drugs than fast neutrons. The mass attenuation factor for both fast and thermal neutrons increases with increasing weight percentages of hydrogen and is found to be higher for thermal neutrons. This is the first study in the literature to investigate the radiation interaction parameters for immunotherapy drugs, and it is helpful in radiation therapy and dosimetry.
{"title":"Study of gamma, neutron, and proton interaction parameters of some immunotherapy drugs using EpiXs, NGCal, and PSTAR software","authors":"Gangadharayya Hiremath, Vishwanath Singh, Narasimha Ayachit, Nagappa Badiger","doi":"10.1515/ract-2023-0255","DOIUrl":"https://doi.org/10.1515/ract-2023-0255","url":null,"abstract":"In proton therapy, the protons are used to destroy the cancer cells efficiently at the Bragg peak without much damage to normal cells. The protons can also produce neutrons, protons, and high-energy gamma rays through nuclear reactions with cancerous and healthy tissues as well as with beamline components. The effective observed dose in the therapy is enhanced due to the interaction of nuclear particles with cancerous tissues. Such nuclear particles can have several effects on drugs used in immunotherapy, such as immunotherapy in combination with proton therapy, which has been used to treat cancer. In the present investigations, the gamma, neutron, and protons interaction parameters of some immunotherapy drugs, such as dostarlimab, atezolizumab, ipilimumab, nivolumab, and pembrolizumab, are determined by using EpiXs, NGCal, and PSTAR software. It is found that the EBF and EABF for all selected immunotherapy drugs increase with increasing penetration depth, peaking at 100 keV. The peaking is more symmetric at a higher penetration depth of 40 mfp than at a lower one of 1 mfp. At lower energies of gamma photons, the EBF values increase exponentially, and at higher energies, they increase linearly with increasing penetration depth for all selected drugs. Mass attenuation factors are slightly higher for thermal neutrons than for fast neutrons for selected immunotherapeutic drugs, indicating that thermal neutrons more actively participate in these drugs than fast neutrons. The mass attenuation factor for both fast and thermal neutrons increases with increasing weight percentages of hydrogen and is found to be higher for thermal neutrons. This is the first study in the literature to investigate the radiation interaction parameters for immunotherapy drugs, and it is helpful in radiation therapy and dosimetry.","PeriodicalId":21167,"journal":{"name":"Radiochimica Acta","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2024-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140929251","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Patient specific treatments for different cancers are currently being actively addressed through nuclear medicine. More recently, the identification of biomarker namely; prostate-specific membrane antigen (PSMA) expressed on the prostate cancer cell surface has been considered as a turning point in prostate cancer management using radiopharmaceuticals. In this treatment method, apart from radionuclide, organic ligands that target PSMA constitute an essential component. PSMA-11 and PSMA-617 are two important ligands that form the radiopharmaceuticals, [68Ga]Ga-PSMA-11, [177Lu]Lu-PSMA-617, which are currently powering the prostate cancer management, especially metastatic castration resistant prostate cancer (mCRPC) in most part of the world. Identification of efficient synthetic routes towards these highly expensive ligands is an important prerequisite to make this treatment modality more popular. In this account, the synthetic challenges that we circumvent during the solution phase synthesis of PSMA-11 and PSMA-617, through different chemical synthetic routes are demonstrated. Post-synthesis, both the ligands, PSMA-11 and PSMA-617 were successfully radiolabelled using 68Ga, and 177Lu, respectively, to generate corresponding labelled products [68Ga]Ga-PSMA-11, and [177Lu]Lu-PSMA-617, in good radiochemical purity.
{"title":"Challenges in the solution phase synthesis of PSMA-11 and PSMA-617: organic ligands for radiopharmaceutical preparations in prostate cancer medication","authors":"K. S. Ajish Kumar, Anupam Mathur","doi":"10.1515/ract-2024-0280","DOIUrl":"https://doi.org/10.1515/ract-2024-0280","url":null,"abstract":"Patient specific treatments for different cancers are currently being actively addressed through nuclear medicine. More recently, the identification of biomarker namely; prostate-specific membrane antigen (PSMA) expressed on the prostate cancer cell surface has been considered as a turning point in prostate cancer management using radiopharmaceuticals. In this treatment method, apart from radionuclide, organic ligands that target PSMA constitute an essential component. PSMA-11 and PSMA-617 are two important ligands that form the radiopharmaceuticals, [<jats:sup>68</jats:sup>Ga]Ga-PSMA-11, [<jats:sup>177</jats:sup>Lu]Lu-PSMA-617, which are currently powering the prostate cancer management, especially metastatic castration resistant prostate cancer (mCRPC) in most part of the world. Identification of efficient synthetic routes towards these highly expensive ligands is an important prerequisite to make this treatment modality more popular. In this account, the synthetic challenges that we circumvent during the solution phase synthesis of PSMA-11 and PSMA-617, through different chemical synthetic routes are demonstrated. Post-synthesis, both the ligands, PSMA-11 and PSMA-617 were successfully radiolabelled using <jats:sup>68</jats:sup>Ga, and <jats:sup>177</jats:sup>Lu, respectively, to generate corresponding labelled products [<jats:sup>68</jats:sup>Ga]Ga-PSMA-11, and [<jats:sup>177</jats:sup>Lu]Lu-PSMA-617, in good radiochemical purity.","PeriodicalId":21167,"journal":{"name":"Radiochimica Acta","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2024-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140833470","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
D. H. Nhon, Nguyen Van Quan, Phan Son Hai, Bui Van Vuong, Nguyen Ngoc Anh, N. Đ. Ve, Hoang Thi Chien
Using gamma and alpha spectrometers, the radioactive isotopes 226Ra, 210Pb, 232Th, and 40K were determined in three sediment cores from the Tam Giang-Cau Hai (TG), Thi Nai (TN), and Nai (DN) lagoons, and radiation risk indices were computed. The radioactivity concentrations of 210Pb, 40K, 232Th, and 226Ra were 55.46 Bq/kg, 675.78 Bq/kg, 67.22 Bq/kg, and 34.15 Bq/kg, respectively. The Raeq, ADR, AEDE, Iγr, AUI, Hex, and AGDE indices were 182.31 Bq/kg, 84.46 nGy/h, 0.10 mSV/y, 1.35, 1, 18, 0.49, and 598.71 µSV/y, respectively; the values of 40K, 232Th, AEDE, ADR, Iγr, and AGDE were greater than the global average and UNSCEAR values. The radioactivity and radiation risk indices decreased in the order DN > TN > TG.
{"title":"Assessment of radioactivity and radiological risk indices in the sediments of the Tam Giang-Cau Hai, Thi Nai, and Nai lagoons in the Center of Vietnam","authors":"D. H. Nhon, Nguyen Van Quan, Phan Son Hai, Bui Van Vuong, Nguyen Ngoc Anh, N. Đ. Ve, Hoang Thi Chien","doi":"10.1515/ract-2024-0271","DOIUrl":"https://doi.org/10.1515/ract-2024-0271","url":null,"abstract":"\u0000 Using gamma and alpha spectrometers, the radioactive isotopes 226Ra, 210Pb, 232Th, and 40K were determined in three sediment cores from the Tam Giang-Cau Hai (TG), Thi Nai (TN), and Nai (DN) lagoons, and radiation risk indices were computed. The radioactivity concentrations of 210Pb, 40K, 232Th, and 226Ra were 55.46 Bq/kg, 675.78 Bq/kg, 67.22 Bq/kg, and 34.15 Bq/kg, respectively. The Raeq, ADR, AEDE, Iγr, AUI, Hex, and AGDE indices were 182.31 Bq/kg, 84.46 nGy/h, 0.10 mSV/y, 1.35, 1, 18, 0.49, and 598.71 µSV/y, respectively; the values of 40K, 232Th, AEDE, ADR, Iγr, and AGDE were greater than the global average and UNSCEAR values. The radioactivity and radiation risk indices decreased in the order DN > TN > TG.","PeriodicalId":21167,"journal":{"name":"Radiochimica Acta","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2024-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140655752","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The presence of chromate in the aquatic environment poses toxicity and pollution to the environment. Therefore, the needs to establish methods to get rid of this species is a must. The effect of different natural rock minerals; pyrite, magnetite, pyrrhotite, and wurtzite as constituent parts of the Earth’s crust can play a major role in waste treatment. The properties of those minerals towards the behavior of chromium (sorption) were studied under the effect of changes of pH and contact time to treat the waste solution of toxic chromate. The total chromium species in the reaction system was determined using Cr51 as a simpler, faster and more accurate analytical tools. Concerning the effect of types of minerals, the synthetic ones, the results indicated that pyrrhotite and wurtzite were highly effective for the removal of chromate with almost 100 % sorption capacity as it was pH-independent, despite the presence of a degree of reductive ability of both minerals. While, it was 99 % at pH 8.5 and 28 % at pH 3 for pyrite and magnetite, respectively, which was pH dependent. The equilibrium adsorption capacities for chromium adsorption were 0.34 ± 0.15, 0.028 ± 0.01 and 4.27 ± 1.3 mg/g mineral for natural minerals pyrite, magnetite and synthetic one pyrhotite, respectively. However, it was found 117.7 ± 10.9 mg/g for synthetic mineral wurtzite. These results can be attributed to the redox power of oxide and sulfide minerals; magnetite and, pyrite used. For kinetic studies of chromium (VI) adsorption, non linear model approved that the reaction could be described based on pseudo-second-order kinetics in such simulated environmental heterogeneous systems.
{"title":"Chromium sorption on synthetic and natural rock minerals with emphasis on speciation behavior and kinetic model using Cr51","authors":"Ashraf A. El-Sayed","doi":"10.1515/ract-2023-0240","DOIUrl":"https://doi.org/10.1515/ract-2023-0240","url":null,"abstract":"\u0000 The presence of chromate in the aquatic environment poses toxicity and pollution to the environment. Therefore, the needs to establish methods to get rid of this species is a must. The effect of different natural rock minerals; pyrite, magnetite, pyrrhotite, and wurtzite as constituent parts of the Earth’s crust can play a major role in waste treatment. The properties of those minerals towards the behavior of chromium (sorption) were studied under the effect of changes of pH and contact time to treat the waste solution of toxic chromate. The total chromium species in the reaction system was determined using Cr51 as a simpler, faster and more accurate analytical tools. Concerning the effect of types of minerals, the synthetic ones, the results indicated that pyrrhotite and wurtzite were highly effective for the removal of chromate with almost 100 % sorption capacity as it was pH-independent, despite the presence of a degree of reductive ability of both minerals. While, it was 99 % at pH 8.5 and 28 % at pH 3 for pyrite and magnetite, respectively, which was pH dependent. The equilibrium adsorption capacities for chromium adsorption were 0.34 ± 0.15, 0.028 ± 0.01 and 4.27 ± 1.3 mg/g mineral for natural minerals pyrite, magnetite and synthetic one pyrhotite, respectively. However, it was found 117.7 ± 10.9 mg/g for synthetic mineral wurtzite. These results can be attributed to the redox power of oxide and sulfide minerals; magnetite and, pyrite used. For kinetic studies of chromium (VI) adsorption, non linear model approved that the reaction could be described based on pseudo-second-order kinetics in such simulated environmental heterogeneous systems.","PeriodicalId":21167,"journal":{"name":"Radiochimica Acta","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2024-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140669783","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Khaled F. El-Nemr, Hamdi Radi, Aman I. Khalaf, Eman M. Hamdy
A comparative study was carried out between ionizing radiation and dicumyl peroxide (Dicup) as two different curing systems for nitrile rubber (NBR) reinforced with different concentrations of multi-walled carbon nanotubes (MWCNTs). Upon ionizing irradiation, the tensile strength (TS) of the composites increases with increasing absorbed dose up to 50 kGy and then decreases with increasing absorbed dose. TS also increases with increasing of MWCNTs content up to 0.75 phr (part per hundred part of rubber). TS values are decreased in the case of Dicup curing as compared with radiation curing. Other characterizations were made, such as the Differential Scanning Calorimeter (DSC), Fourier transform infrared spectroscopies (FTIR), and morphological characterization, which give further implications for the good compatibility between MWCNTs and NBR phases. A study of the effect of fuel on NBR/MWCNTs composites showed that the composites cured by Dicup had lower values for swelling in fuels when compared with others that were cured by radiation.
{"title":"Insight on the properties of multi-walled carbon nanotubes reinforced nitrile rubber composites cured by ionizing radiation or peroxide: a comparative study","authors":"Khaled F. El-Nemr, Hamdi Radi, Aman I. Khalaf, Eman M. Hamdy","doi":"10.1515/ract-2023-0244","DOIUrl":"https://doi.org/10.1515/ract-2023-0244","url":null,"abstract":"A comparative study was carried out between ionizing radiation and dicumyl peroxide (Dicup) as two different curing systems for nitrile rubber (NBR) reinforced with different concentrations of multi-walled carbon nanotubes (MWCNTs). Upon ionizing irradiation, the tensile strength (TS) of the composites increases with increasing absorbed dose up to 50 kGy and then decreases with increasing absorbed dose. TS also increases with increasing of MWCNTs content up to 0.75 phr (part per hundred part of rubber). TS values are decreased in the case of Dicup curing as compared with radiation curing. Other characterizations were made, such as the Differential Scanning Calorimeter (DSC), Fourier transform infrared spectroscopies (FTIR), and morphological characterization, which give further implications for the good compatibility between MWCNTs and NBR phases. A study of the effect of fuel on NBR/MWCNTs composites showed that the composites cured by Dicup had lower values for swelling in fuels when compared with others that were cured by radiation.","PeriodicalId":21167,"journal":{"name":"Radiochimica Acta","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2024-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140610898","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Rehab Sokary, Heba A. Raslan, Rasha Mohammad Fathy
The most common ways to produce nanoparticles are through chemical and physical processes, which can be expensive and environmentally hazardous. Using plant extracts (green synthesis) as reducing and capping agents is a simple, cost-effective, and environmentally friendly method of lowering the usage of dangerous chemicals in the synthesis of metal nanoparticles. This study covers the environmentally friendly synthesis of cadmium sulphide nanoparticles (CdS NPs) using a blend of flaxseed extracts (FM), polyvinyl alcohol (PVA), and chitosan (Cs). The composites are then exposed to gamma irradiation at doses of 20 kGy and 40 kGy. UV–VIS absorption spectroscopy, SEM, HRTEM, EDX, and FTIR were used to analyse the produced nanocomposite films. UV–Vis absorption spectra showed considerable surface Plasmon resonance (SPR) bands at 396–440 nm, indicating that CdS NPs had been successfully synthesized. A progressive red shift in wavelength was noted, along with the broadening of the absorption band as the irradiation dose increased. Transmission electron microscopy pictures revealed that the generated CdS nanostructures were dispersed as spherical nanoparticles with remarkable structural homogeneity. Tensile strength and elongation measurements of the films revealed that the inclusion of CdS NPs improved their mechanical properties. The addition of CdS NPs to the current blends limits biodegradation in soil. Thermal gravimetric analysis findings showed that CdS NPs included in FM/PVA films had improved thermal stability. The antimicrobial activities of the tested films were performed against Staphylococcus aureus, Escherichia coli, and Candida albicans. The results revealed that all of the films exhibited more antibacterial activity against S. aureus than the two others, with the highest activity observed in nanocomposites with a high concentration of CdS.
{"title":"Green synthesis of CdS/flaxseed mucilage nanocomposite films using gamma irradiation for packaging applications","authors":"Rehab Sokary, Heba A. Raslan, Rasha Mohammad Fathy","doi":"10.1515/ract-2023-0251","DOIUrl":"https://doi.org/10.1515/ract-2023-0251","url":null,"abstract":"The most common ways to produce nanoparticles are through chemical and physical processes, which can be expensive and environmentally hazardous. Using plant extracts (green synthesis) as reducing and capping agents is a simple, cost-effective, and environmentally friendly method of lowering the usage of dangerous chemicals in the synthesis of metal nanoparticles. This study covers the environmentally friendly synthesis of cadmium sulphide nanoparticles (CdS NPs) using a blend of flaxseed extracts (FM), polyvinyl alcohol (PVA), and chitosan (Cs). The composites are then exposed to gamma irradiation at doses of 20 kGy and 40 kGy. UV–VIS absorption spectroscopy, SEM, HRTEM, EDX, and FTIR were used to analyse the produced nanocomposite films. UV–Vis absorption spectra showed considerable surface Plasmon resonance (SPR) bands at 396–440 nm, indicating that CdS NPs had been successfully synthesized. A progressive red shift in wavelength was noted, along with the broadening of the absorption band as the irradiation dose increased. Transmission electron microscopy pictures revealed that the generated CdS nanostructures were dispersed as spherical nanoparticles with remarkable structural homogeneity. Tensile strength and elongation measurements of the films revealed that the inclusion of CdS NPs improved their mechanical properties. The addition of CdS NPs to the current blends limits biodegradation in soil. Thermal gravimetric analysis findings showed that CdS NPs included in FM/PVA films had improved thermal stability. The antimicrobial activities of the tested films were performed against <jats:italic>Staphylococcus aureus</jats:italic>, <jats:italic>Escherichia coli</jats:italic>, and <jats:italic>Candida albicans</jats:italic>. The results revealed that all of the films exhibited more antibacterial activity against <jats:italic>S. aureus</jats:italic> than the two others, with the highest activity observed in nanocomposites with a high concentration of CdS.","PeriodicalId":21167,"journal":{"name":"Radiochimica Acta","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2024-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140564247","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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