Carbonate Research Articles

CO2 Loss into Solution: An Experimental Investigation of CO2 Electrolysis with a Membrane Electrode Assembly Cell.

In pursuit of commercial viability for carbon dioxide (CO2) electrolysis, this study investigates the operational challenges associated with membrane electrode assembly (MEA)-type CO2 electrolyzers, with a focus on CO2 loss into the solution phase through bicarbonate (HCO3 -) and carbonate (CO3 2-) ion formation. Utilizing a silver electrode known for selectively facilitating CO2 to CO conversion, the molar production of CO2, CO, and H2 is measured across a range of current densities from 0 to 600 mA/cm2, while maintaining a constant CO2 inlet flow rate of 58 mL/min. The dynamics of CO2 loss are monitored through measurements of pH changes in the electrolyte and carbon elemental balance analysis. Employing the concept of conservation of elemental carbon, a chemical reaction analysis is conducted, identifying the critical role of the hydroxide (OH-) ion. At lower current densities below 125 mA/cm2, where CO2 reduction predominates, it is observed that CO2 loss is proportional to current density, reaching up to 0.18 mmol/min, and directly correlates with the rate of OH- ion production, indicative of HCO3 -/CO3 2- ion formation. Conversely, at higher current densities above 450 mA/cm2, where hydrogen evolution is the dominant process, CO2 loss is shown to decouple from the OH- ion production rate with a constant limit condition of 0.12 mmol/min, regardless of the current density. This suggests that electrolyte-induced cathode flooding restricts CO2 access to cathode sites. Additionally, pH change in the electrolyte during the electrolysis further infers differing ion populations in the CO2 reduction and hydrogen evolution regimes, and their movement across the membrane. Continued monitoring of the pH change after the cessation of electricity offers insights into the accumulation of HCO3 -/CO3 2- ion at the cathode, influencing salt formation.

Clinical Outcomes of Carbon Ion Radiation Therapy for Malignant Peripheral Nerve Sheath Tumors

Purposeto investigate outcome and toxicity of patients affected by malignant peripheral nerve sheath tumors (MPNSTs) treated with high-dose carbon ion radiotherapy (CIRT). Patients and methodswe retrospectively analyzed the outcome of 23 patients with MPNST treated between July 2013 and December 2020. Out of these, 13 patients (56.5%) had incompletely resected tumors, 8 patients (34.7%) experienced recurrence after surgery, and 2 patients (8.7%) had unresectable tumors. Before CIRT treatment, 4 patients underwent a second surgery after the first local recurrence (LR), and 1 patient underwent a third surgery for the second local relapse of disease. Six (26%) of patients received neoadjuvant chemotherapy. The most frequent tumor site was brachial plexus (N=9; 39.1%). In five patients (21.7%) neurofibromatosis type 1 (NF1) disorder was found, while 4 patients (17, 4%) had radiation-induced MPNST. The median CIRT prescribed total dose was 69.8 Gy [RBE] (range, 54-76.8) delivered in a median of 16 fractions (range, 15-22). Eleven patients (47.82%) were treated according to a sequential boost protocol with a median prescribed dose to CTV-LR of 45 Gy[RBE] (range, 41.4 – 54). ResultsAfter a median follow-up time of 23 months (range 3-100 months), the OS rates at 1-year and 2-year were respectively: 82.38%, 61.51%. The 1-year and 2-year LRFS rates were respectively: 65.07%, 48.80%; the 1-year and 2-year PFS rates were respectively: 56.37%, 40.99%. No patients showed acute or late Grade 4 toxicity or any treatment-related deaths. Ten patients (43.48%) reported acute toxicities of Grade ≥2: dermatitis in 6 patients, mucositis in 2 patients, peripheral neuropathy in 4 patients. Eight patients (34.78%) reported late toxicities of Grade ≥2, mainly due to loco-regional neuropathy. Conclusionshigh dose CIRT shows favorable local effect with acceptable toxicities in patients with gross residual and LR after surgery, or unresectable malignant peripheral nerve sheath tumors. Advanced treatment modalities such as particle therapy should be considered for MPNSTs.

First Dosimetric and Biological Verification for Spot-Scanning Hadron Arc Radiation Therapy With Carbon Ions

Purpose: Spot-scanning Hadron Arc therapy (SHArc) is a novel delivery technique for ion beams with potentially improved dose conformity and dose-averaged linear energy transfer (LETd) redistribution. The first dosimetric validation and in vitro verification of carbon ion arc delivery is presented. Methods: Intensity Modulated Particle Therapy (IMPT) and SHArc plans were designed to deliver homogenous physical dose or biological dose in a cylindrical PMMA phantom. Additional IMPT carbon plans were optimized for testing different LETd-boosting strategies. Verifications of planned doses were performed with an ionization chamber and clonogenic survival assay was conducted using A549 cancer lung cell line. Radiation-induced nuclear 53BP1 foci were assessed to evaluate the cellular response in both normoxic and hypoxic conditions. Results: Dosimetric measurements and clonogenic assay results showed a good agreement to planned dose and survival distributions. Measured survival fractions and foci confirmed carbon ions SHArc as potential modality to overcome hypoxia-induced radio-resistance. LETd-boosted IMPT plans reached similar LETd in the target as in SHArc plans promising similar features against hypoxia but at the cost of an increased entrance dose. SHArc resulted, however, in a lower dose bath but in a larger volume around the target. Conclusion: The first proof of principle of carbon ions SHArc delivery was performed and experimental evidence suggests this novel modality as an attractive approach for treating hypoxic tumor.

Synthesis, photoluminescence, Judd-Ofelt parameters, and high energy neutron/charged particle transmission efficiencies of Nd3+ ion-activated sodium-borate glasses

Sodium borate glasses doped with Nd3+ ions and having the molar formulations 75B2O3 – 15Na2O – 9.5x – 0.5Nd2O3, where x = Bi2O3; SrO and Li2O were prepared by employing the melt quenching technique. The glasses were coded as BiNd, SrNd, and LiNd for x = Bi2O3; SrO and Li2O, respectively. The prepared glasses were characterized for their physical and optical attributes. The influence of the glass composition on the photoluminescence and fast neutron (FN) and charged radiation (CR) transmission efficiencies were also investigated. The density of BiNd, SrNd, and LiNd is 3.32, 2.43, and 3.32 g/cm3, respectively. Optical constants of the glasses showed variations with glass composition. The FTIR study of the glass also revealed the structure of the glasses. The BiNd glass has the most intense PL of all the samples, followed by SrNd glass, while LiNd had the weakest PL emission. The value of for BiNd, SiNd, and LiNd is 0.1029 cm-1, 0.1009 cm-1, and 0.0987 cm-1, respectively. The projected ranges of electrons, protons, helium ions, and carbon ions were generally lower for denser XNd glass. The XNd glasses are potentially useful of optical, shielding and dosimetry applications.

Effect of inorganic salt impurities on seeded precipitation of silica hydrate from sodium silicate solution

To clarify the precipitation of silica hydrate from the real desilication solutions of aluminosilicate solid wastes by adding seeds and improve integrated waste utilization, the seeded precipitation was studied using synthesized sodium silicate solution containing different inorganic salt impurities. The results show that sodium chloride, sodium sulfate, sodium carbonate, or calcium chloride can change the siloxy group structure. The number of high-polymeric siloxy groups decreases with increasing sodium chloride or sodium sulfate concentration, which is detrimental to seeded precipitation. Calcium chloride favors the polymerization of silicate ions, and even the chain groups precipitate with the precipitation of high-polymeric sheet and cage-like siloxy groups. The introduced sodium cations in sodium carbonate render a more open network structure of high-polymeric siloxy groups, although the carbonate ions favor the polymerization of siloxy groups. No matter how the four impurities affect the siloxy group structure, the precipitates are always amorphous opal-A silica hydrate.

Particle therapy in gastrointestinal cancer-a narrative review.

Radiation therapy is one of the main pillars in the treatment of gastrointestinal (GI) cancers, especially esophageal and anorectal malignancies. The worldwide standard of care is yet an irradiation with photons. Though not commonly used, charged particles offer some physical advantages with a highly conformal dose distribution, which allows an even better sparing of organs at risk. In addition to dosimetric advantages, heavy-ion beams like carbon ions may offer an additional set of biological advantages. Because particle therapy is not standard of care, data are scarce-especially concerning the use in GI malignancies. The aim of this review is to provide a compact overview of the currently available literature. PubMed and Web of Science databases were searched for publications on particle radiotherapy in GI cancer (e.g., proton therapy in esophageal cancer, carbon ion radiotherapy in pancreatic cancer). Here we present a review of the current data on particle therapy with regard to esophageal, pancreatic, hepatic and anorectal malignancies. Data on particle therapy in GI cancer are scarce. Nevertheless, the current literature shows some promising results. Further clinical evidence, especially randomized trials, is crucial to augment the role of particle radiotherapy in GI cancer.

Comprehensive approach integrating water quality index and toxic element analysis for environmental and health risk assessment enhanced by simulation techniques

Due to water shortages and the potential impact of Ethiopia’s new dam on the Nile River, Egypt is seeking new water resources. This study assesses the drinking water quality and associated risks from potentially toxic elements (PTEs) in the Quaternary aquifer (QA) in Beni-Suef, Egypt. Using a comprehensive approach, including PHREEQC geochemical modeling, ionic ratios, multivariate statistical analyses, and the integrated weight water quality index (WQI), the study evaluated the sources of ion contamination and the mixing of Nile water with QA. Various indices, such as the Heavy Metal Pollution Index (HPI), ecological Risk Index (RI), Hazard Quotient (HQ), and Hazard Index (HI), were used to assess ecological and health risks. Monte Carlo simulations provided probabilistic assessments of non-carcinogenic risks for adults and children. GIS tools were used to map risk indices, identifying the most deteriorated locations for sustainable management. The hydrochemical analysis revealed water facies including Na–Cl, Ca–Mg–HCO3, and mixed types, influenced by carbonate dissolution, ion exchange, and silicate weathering. Contamination sources, particularly in the north and south, were linked to agricultural activities, irrigation return flow, municipal waste, and evaporation. The WQI indicated that 10.14% of samples were extremely poor, 21.7% were poor, 26% were medium, and 42% were good to excellent. PTE contamination varied, with HPI values indicating good water quality in the central area in 53.6% of the collected samples (HPI < 30), but contamination in the north and south is high (HPI > 51). Ecological Risk Index values were below the threshold in 100% of samples (RI < 30), confirming water safety regarding PTEs. In comparison, for hazard index (HI) through oral/ingestion, adults exhibited HI values ranging from 0.012 to 2.16, while children showed higher values, ranging from 0.045 to 8.25. However, the hazard index for oral/ingestion exceeded safe limits in the north and south (HI oral > 1), posing non-carcinogenic risks. Monte Carlo simulations revealed significant risks from oral exposure to manganese (HQ oral > 1), particularly in El-Wasta and El-Fashn, necessitating further treatment and management.

1413: Can NRAS mutation status predict outcome in head and neck mucosal melanoma treated with carbon ions?

1413: Can NRAS mutation status predict outcome in head and neck mucosal melanoma treated with carbon ions?

1872: Apparent diffusion coefficient maps as early biomarker for carbon ion RT in adenoid cystic carcinoma

1872: Apparent diffusion coefficient maps as early biomarker for carbon ion RT in adenoid cystic carcinoma

Pilot study to assess the early cardiac safety of carbon ion radiotherapy for intra- and para-cardiac tumours.

Modern photon radiotherapy effectively spares cardiac structures more than previous volumetric approaches. Still, it is related to non-negligible cardiac toxicity due to the low-dose bath of surrounding normal tissues. However, the dosimetric advantages of particle radiotherapy make it apromising treatment for para- and intra-cardiac tumours. In the current short report, we evaluate the cardiac safety profile of carbon ion radiotherapy (CIRT) for radioresistant intra- and para-cardiac malignancies in areal-world setting. We retrospectively analysed serum biomarkers (TnI, CRP and NT-proBNP), echocardiographic, and both 12-lead and 24-hour Holter electrocardiogram (ECG) data of consecutive patients with radioresistant intra- and para-cardiac tumours irradiated with CIRT between June 2019 and September 2022. In the CIRT planning optimization process, to minimize the delivered doses, we contoured and gave ahigh priority to the cardiac substructures. Weekly re-evaluative 4D computed tomography scans were carried out throughout the treatment. Atotal of 16patients with intra- and para-cardiac localizations of radioresistant tumours were treated up to atotal dose of 70.4 Gy relative biological effectiveness (RBE) and amean heart dose of 2.41 Gy(RBE). We did not record any significant variation of the analysed serum biomarkers after CIRT nor significant changes of echocardiographic features, biventricular strain, or 12-lead and 24-hour Holter ECG parameters during 6months of follow-up. Our pilot study suggests that carbon ion radiotherapy is apromising radiation technique capable of sparing off-target side effects at the cardiac level. Alarger cohort, long-term follow-up and further prospective studies are needed to confirm these findings.

2642: Comparing Dosimetry and RT pneumonitis risk between carbon ion radiotherapy and SABR in lung cancer

2642: Comparing Dosimetry and RT pneumonitis risk between carbon ion radiotherapy and SABR in lung cancer

1922: Prompt Gamma Imaging for range verification in Carbon Ion Radiation Therapy

1922: Prompt Gamma Imaging for range verification in Carbon Ion Radiation Therapy

2186: Dosimetric comparison of carbon ion and proton beam therapy for large primary renal cell cancer

2186: Dosimetric comparison of carbon ion and proton beam therapy for large primary renal cell cancer

1883: Benefits and limitations of LETd optimization for carbon ion radiotherapy in sacral chordomas

1883: Benefits and limitations of LETd optimization for carbon ion radiotherapy in sacral chordomas

2990: Monte Carlo calculated beam quality correction factors for ionization chambers in carbon ion beams

2990: Monte Carlo calculated beam quality correction factors for ionization chambers in carbon ion beams

The Potential for Targeting G2/M Cell Cycle Checkpoint Kinases in Enhancing the Efficacy of Radiotherapy.

Radiotherapy is one of the main cancer treatments being used for ~50% of all cancer patients. Conventional radiotherapy typically utilises X-rays (photons); however, there is increasing use of particle beam therapy (PBT), such as protons and carbon ions. This is because PBT elicits significant benefits through more precise dose delivery to the cancer than X-rays, but also due to the increases in linear energy transfer (LET) that lead to more enhanced biological effectiveness. Despite the radiotherapy type, the introduction of DNA damage ultimately drives the therapeutic response through stimulating cancer cell death. To combat this, cells harbour cell cycle checkpoints that enables time for efficient DNA damage repair. Interestingly, cancer cells frequently have mutations in key genes such as TP53 and ATM that drive the G1/S checkpoint, whereas the G2/M checkpoint driven through ATR, Chk1 and Wee1 remains intact. Therefore, targeting the G2/M checkpoint through specific inhibitors is considered an important strategy for enhancing the efficacy of radiotherapy. In this review, we focus on inhibitors of Chk1 and Wee1 kinases and present the current biological evidence supporting their utility as radiosensitisers with different radiotherapy modalities, as well as clinical trials that have and are investigating their potential for cancer patient benefit.

Utilizing Magnesium Carbonate Induced by CO2 to Modify the Performance of Plastic Clay

Highly plastic clays pose significant challenges in engineering projects. Various techniques have been employed to enhance their properties, though many face difficulties related to implementation and environmental impact. This study examines the effect of CO2-induced magnesium carbonate on improving the geotechnical behavior of plastic clay. CO2-induced magnesium carbonate was produced via mineral carbonation and used to improve the behavior of highly plastic natural clay. CO2 gas was injected into a sodium hydroxide solution to produce carbonate ions (CO32−). Magnesium carbonate was precipitated on a laboratory scale by adding magnesium sulfate solution to the carbonate ion solution. Clayey soil samples were obtained from test pits in the Meyghan Plain near Arak, Iran. The clay samples were treated with different percentages of the produced magnesium carbonate. Various parameters of the treated and untreated samples, including index properties, unconfined compressive strength, consolidation behavior, and swelling potential, were studied. It was found that the liquid limit and plasticity index of the treated clay decreased as the magnesium carbonate content increased. The soil classification changed from high plastic clay (CH) to low plastic silt (ML) with the addition of 15% magnesium carbonate to the highly plastic clay. The unconfined compressive strength of the treated clay increased. Additionally, the consolidation behavior and swelling index of the treated clay improved as the magnesium carbonate content increased. This study confirms that CO2-induced magnesium carbonate is a promising material for improving the behavior of highly plastic clays, offering a sustainable approach to environmental management.

Sea spray allows for the growth of subaerial microbialites at the driest desert on Earth

Due to its extreme conditions, microbial life in the Atacama Desert is known to survive in well-protected micro-habitats (hypolithic, endolithic, etc.), but rarely directly exposed to the environment, that is, epilithic habitats. Here we report a unique site, La Portada, a cliff confronting the Pacific Ocean in the Coastal Range of this desert, in which the constant input of water provided by the sea spray allows for the growth of a black-colored epilithic subaerial microbial ecosystem. Formed by a complex community of halophilic microorganisms belonging to the three domains of life, this ecosystem displays the typical three-dimensional structure of benthic microbialites, coherent with the presence of a diversity of cyanobacteria (including species from the genera that are known to form them), a constant high water activity and an ample availability of carbonate ions. From these microbialites we isolated Hortae werneckii, a fungal species which by producing melanin, not only explains the dark color of these microbialites, but may also play the role of protecting the whole community from extreme UV radiation. A number of biosignatures not only confirmed sea spray as the main source of water, but also suggests that one place to consider for the search of evidences of life on Mars would be on the paleo-coastlines that surrounded vanished oceans such as that on Aeolis Dorsa.

Radiosensitizing Effect of PARP Inhibition on Chondrosarcoma and Chondrocyte Cells Is Dependent on Radiation LET.

Chondrosarcoma is a rare malignant tumor that forms in bone and cartilage. The primary treatment involves surgical removal of the tumor with a margin of healthy tissue. Especially if complete surgical removal is not possible, radiation therapy and chemotherapy are used in conjunction with surgery, but with a generally low efficiency. Ongoing researches are focused on understanding the genetic and molecular basis of chondrosarcoma following high linear energy transfer (LET) irradiation, which may lead to treatments that are more effective. The goal of this study is to evaluate the differential effects of DNA damage repair inhibitors and high LET irradiation on chondrosarcoma versus chondrocyte cells and the LET-dependency of the effects. Two chondrosarcoma cell lines with different IDH mutation status and one chondrocyte cell line were exposed to low LET (X-ray) and high LET (carbon ion) irradiation in combination with an Olaparib PARP inhibitor. Cell survival and DNA repair mechanisms were investigated. High LET irradiation drastically reduced cell survival, with a biological efficiency three times that of low LET. Olaparib significantly inhibited PARylation in all the tested cells. A significant reduction in cell survival of both chondrosarcoma and chondrocyte cells was observed following the treatment combining Olaparib and X-ray. PARP inhibition induced an increase in PARP-1 expression and a reduced effect on the cell survival of WT IDH chondrosarcoma cells. No radiosensitizing effect was observed in cells exposed to Olaparib paired with high LET irradiation. NHEJ was activated in response to high LET irradiation, neutralizing the PARP inhibition effect in both chondrosarcoma cell lines. When high LET irradiation is not available, PARP inhibition could be used in combination with low LET irradiation, with significant radiosensitizing effects on chondrosarcoma cells. Chondrocytes may be affected by the treatment combination too, showing the need to preserve normal tissues from radiation fields when this kind of treatment is suggested.

Characterization of Lithium-Ion Battery Fire Emissions—Part 1: Chemical Composition of Fine Particles (PM2.5)

Lithium-ion batteries (LIB) pose a safety risk due to their high specific energy density and toxic ingredients. Fire caused by LIB thermal runaway (TR) can be catastrophic within enclosed spaces where emission ventilation or occupant evacuation is challenging or impossible. The fine smoke particles (PM2.5) produced during a fire can deposit in deep parts of the lung and trigger various adverse health effects. This study characterizes the chemical composition of PM2.5 released from TR-driven combustion of cylindrical lithium iron phosphate (LFP) and pouch-style lithium cobalt oxide (LCO) LIB cells. Emissions from cell venting and flaming combustion were measured in real time and captured by filter assemblies for subsequent analyses of organic and elemental carbon (OC and EC), elements, and water-soluble ions. The most abundant PM2.5 constituents were OC, EC, phosphate (PO43−), and fluoride (F−), contributing 7–91%, 0.2–40%, 1–44%, and 0.7–3% to the PM2.5 mass, respectively. While OC was more abundant during cell venting, EC and PO43− were more abundant when flaming combustion occurred. These freshly emitted particles were acidic. Overall, particles from LFP tests had higher OM but lower EC compared to LCO tests, consistent with the higher thermal stability of LFP cells.