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This study compares the accuracy of dosimetry calculations using the Monte Carlo (MC) method and the MIRD method for 99mTc-HMPAO, 99mTc-DMSA, and 99mTc-sulfur colloid administered to an adult female patient undergoing SPECT imaging. Comparing the two methods, the dose estimation differences between MC and MIRD methods were found to be 11.57%, 1.70%, and 30.04% for 99mTc-HMPAO, 99mTc-DMSA, and 99mTc-sulfur colloid, respectively. In conclusion, this study emphasizes the importance of accurate dosimetry in nuclear medicine. The MC method perform better than the MIRD method in predicting absorbed doses, making it a valuable tool for optimizing radiation therapies and improving patient outcomes. [ABSTRACT FROM AUTHOR]

This study evaluates the efficacy of [131I]I-ERIC1 in targeting and inhibiting the growth of SCLC tumors in mice, focusing on tumor accumulation and regression and potential side effects. NCAM-positive NCI-H69 SCLC cells were implanted in CB 17 SCID mice, and [131I]I-ERIC1 biokinetics were measured in organs and tissues at four post-injection time points (24, 72, 96, and 120 h). The experimental series compared tumor growth, survival, and changes in blood counts among three treatment groups (1, 2, or 3 MBq) and a control group, with treatments initiated either two or five days post implantation. [131I]I-ERIC1 was synthesized with >95% radiochemical purity and a specific activity of 15 TBq/mmol. Tumor activity peaked at 31.5 ± 6.6% ID/g after four days, demonstrating significant antitumor efficacy, which resulted in sustained remission and extended survival. Hematological toxicity was observed, with the optimal dose identified as 2 MBq per animal administered two days post implantation. [131I]I-ERIC1 shows promise as a theranostic agent for personalized cancer treatment by effectively targeting SCLC tumors with manageable side effects. However, further studies are required to optimize dosing strategies and minimize toxicity. [ABSTRACT FROM AUTHOR]

Chronic inflammation underpins many severe diseases, often requiring anti-inflammatory drugs that can have adverse effects. Medicinal herbs offer an alternative but suffer from poor solubility, limiting their efficacy. Nanotechnology, particularly zinc oxide nanoparticles (ZnO NPs), presents a promising solution to enhance the therapeutic potential of herbal compounds. This review examines the nature and benefits of ZnO NPs in drug delivery systems compared to other nanomaterials. It highlights the advantages of biogenic synthesis of ZnO NPs, detailing the eco-friendly formation mechanisms and common characterization methods. The anti-inflammatory effects of biosynthesized ZnO NPs over the last five years are comprehensively reviewed, with insights into their mechanisms of action. Additionally, the pharmacokinetic and toxicokinetic profiles of ZnO NPs are explored to understand their biokinetics post-drug release. In conclusion, biogenically synthesized ZnO NPs enhance the bioavailability of medicinal plant compounds, offering a compelling alternative for treating inflammatory conditions. [ABSTRACT FROM AUTHOR]

Global fertilizer production and mismanagement significantly contribute to many harmful environmental impacts, revealing the need for a greater understanding of crop growth and nutrient uptake, which can be used to optimize fertilizer management. This study experimentally adapts first-principles microbial modeling techniques to the hydroponic cultivation of Bibb lettuce (Lactuca sativa) under nitrogen-limited conditions. Monod and Michaelis–Menten's approaches are applied to predict biomass productivity and nutrient uptake and to evaluate the feasibility of reclaimed wastewater as a nutrient source of nitrogen. Experimental and modeling results reveal significantly different kinetic saturation constants ( K s = 1.331 and K m = 17.887 mg L−1) and a corresponding cell yield strongly dependent on nutrient concentration, producing visually and compositionally distinct tissue between treatments receiving ≤ 26.2 and ≥ 41.7 m g N L−1. The resulting Monod model overestimates dry mass predictions during low nutrient conditions, and the collective results support the development of a dynamic Monod curve that is temporally dependent during the plants' lifecycle. Despite this shortcoming, these results support the feasibility of reclaiming nitrogen from wastewater in hydroponic agriculture, expecting to produce lesser biomass lettuce exhibiting healthy tissue. Furthermore, this study provides a mathematical foundation for agricultural simulations and nutrient management. [ABSTRACT FROM AUTHOR]

Introduction: The biokinetics of radioiodine (RAI) in thyroid cancer patients are complex. This study aims to develop a practical approach for assessing RAI biokinetics to predict patient discharge time and estimate radiation exposure to caregivers. Methods: We retrospectively reviewed data from patients with differentiated thyroid carcinoma undergoing RAI treatment. Serial radiation dose rates were dynamically collected during hospitalization and fitted to a biexponential model to assess the biokinetic features: RAI uptake fraction of thyroid tissue (Ft) and effective half-life of extra-thyroid tissue (Tet). Correlations with 99mTc thyroid uptake ratio (TcUR), radiation retention ratio (RR), renal function, and body mass index (BMI) were analyzed. Results: Thirty-five patients were enrolled. The derived Ft was 0.08 ± 0.06 and Tet was 7.57 ± 1.45 h. Pearson's correlation analysis revealed a significant association between Ft and both TcUR and RR (p < 0.05), while Tet correlated with renal function and BMI (p < 0.05). Conclusion: This novel and practical method assessing RAI biokinetics demonstrates consistency with other parameters and related studies, enhancing the model reliability. It shows promise in predicting an appropriate discharge time and estimating radiation exposure to caregivers, allowing for modifications to radiation protection precautions to follow ALARA principle and minimize the potential risks from radiation exposure. [ABSTRACT FROM AUTHOR]

Kinetic analysis of the interaction of four N­substituted nortropane derivatives with the dopamine transporter was made to characterize the mechanism of the binding process. The kinetics were studied by radioligand binding experiments. It was found that the studied compounds initiate a slow isomerization process of the initially formed ligandâtransporter complex, but at higher concentrations, the same compounds inhibit the isomerization process. The results suggest that the studied ligands interact with two distinct binding sites of the transporter protein that have different ligand binding specificities. The interaction of ligands with different binding sites must be taken into consideration when analyzing the ligand recognition patterns of the transporter protein.

Global fertilizer production and mismanagement significantly contribute to many harmful environmental impacts, revealing the need for a greater understanding of crop growth and nutrient uptake, which can be used to optimize fertilizer management. This study experimentally adapts first-principles microbial modeling techniques to the hydroponic cultivation of Bibb lettuce (Lactuca sativa) under nitrogen-limited conditions. Monod and Michaelis–Menten’s approaches are applied to predict biomass productivity and nutrient uptake and to evaluate the feasibility of reclaimed wastewater as a nutrient source of nitrogen. Experimental and modeling results reveal significantly different kinetic saturation constants (Ks = 1.331 and Km = 17.887 mg L−1) and a corresponding cell yield strongly dependent on nutrient concentration, producing visually and compositionally distinct tissue between treatments receiving ≤26.2 and ≥41.7 mgN L−1. The resulting Monod model overestimates dry mass predictions during low nutrient conditions, and the collective results support the development of a dynamic Monod curve that is temporally dependent during the plants’ lifecycle. Despite this shortcoming, these results support the feasibility of reclaiming nitrogen from wastewater in hydroponic agriculture, expecting to produce lesser biomass lettuce exhibiting healthy tissue. Furthermore, this study provides a mathematical foundation for agricultural simulations and nutrient management.

To calculate the contribution of absorbed dose by organs in the biokinetics of Tc-99m when used for radiodiagnosis of the adult male heart employing a Matlab program. Methods: The absorbed self-dose of the adult male heart and absorbed dose by organs in the biokinetics of the heart when administering Tc-99m are estimated using the MIRD formalism and the Cristy-Eckerman representation, which have been employed to develop the algorithm in Matlab. Results: The results indicate that electron capture emissions of 1.446 (mGy/MBq) and Auger electrons of 0.062 (mGy/MBq) are entirely directed towards the target organ (heart) and contribute 29.33% and 1.25% respectively to its total dose. Additionally, the dosimetric contributions of biokinetic organs correspond to characteristic radiation emissions and gamma photons at 2.578 (mGy/MBq) for Tc-99m, representing 52.29% of its total dose. Conclusion: These dosimetric contributions are significant in estimating the total absorbed dose by the heart in adult males and should not be disregarded. [ABSTRACT FROM AUTHOR]

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Abstract Background Toxicokinetics of nanomaterials, including studies on the absorption, distribution, metabolism, and elimination of nanomaterials, are essential in assessing their potential health effects. The fate of nanomaterials after inhalation exposure to multiple nanomaterials is not clearly understood. Methods Male Sprague–Dawley rats were exposed to similar sizes of silver nanoparticles (AgNPs, 10.86 nm) and gold nanoparticles (AuNPs, 10.82 nm) for 28 days (6-h/day, 5-days/week for four weeks) either with separate NP inhalation exposures or with combined co-exposure in a nose-only inhalation system. Mass concentrations sampled from the breathing zone were AuNP 19.34 ± 2.55 μg/m3 and AgNP 17.38 ± 1.88 μg/m3 for separate exposure and AuNP 8.20 μg/m3 and AgNP 8.99 μg/m3 for co-exposure. Lung retention and clearance were previously determined on day 1 (6-h) of exposure (E-1) and on post-exposure days 1, 7, and 28 (PEO-1, PEO-7, and PEO-28, respectively). In addition, the fate of nanoparticles, including translocation and elimination from the lung to the major organs, were determined during the post-exposure observation period. Results AuNP was translocated to the extrapulmonary organs, including the liver, kidney, spleen, testis, epididymis, olfactory bulb, hilar and brachial lymph nodes, and brain after subacute inhalation and showed biopersistence regardless of AuNP single exposure or AuNP + AgNP co-exposure, showing similar elimination half-time. In contrast, Ag was translocated to the tissues and rapidly eliminated from the tissues regardless of AuNP co-exposure. Ag was continually accumulated in the olfactory bulb and brain and persistent until PEO-28. Conclusion Our co-exposure study of AuNP and AgNP indicated that soluble AgNP and insoluble AuNP translocated differently, showing soluble AgNP could be dissolved into Ag ion to translocate to the extrapulmonary organs and rapidly removed from most organs except the brain and olfactory bulb. Insoluble AuNPs were continually translocated to the extrapulmonary organs, and they were not eliminated rapidly.

In radionuclide therapy, activity kinetics in tissues determine the absorbed doses administered and thus efficacy and side effects of treatment. The objective of this work was to derive expressions for the parameters affecting the absorbed dose to a target tissue for first-order activity kinetics.The activity uptake results from contributions from the first-pass activity flow through the target tissue preceding systemic equilibration and uptake after distribution of the administered compound in the body. The absorbed dose from uptake after equilibration is the product of the mean energy deposited per decay in the target tissue, the time integral of the plasma activity concentration, the plasma volume flow per unit target tissue mass, the probability of activity removal during passage, and the mean lifetime of activity in the target tissue.Quantitative analysis of the determinants of absorbed dose exemplarily for radioiodine therapy indicates that the high uptake often observed in Graves’ disease must be associated with high tissue perfusion and removal probability and that administration of stable iodine increases mean lifetime. For therapies with long residence times of the active compound in the blood, such as radioiodine therapy, the contribution of the first-pass is small compared with uptake after equilibration. The relative first-pass contribution is higher for agents that are rapidly eliminated from the blood pool, such as radiolabelled somatostatin analogues, and may dominate after arterial application.Understanding the determining parameters in radionuclide therapy reveals dose-limiting factors and opens up opportunities to optimise and individualize therapy, potentially improving treatment success rates.

Attached-growth systems are biological wastewater treatment processes with biomass attached to a media for organic matter and nutrient removal from wastewater. In this regard, bioreactors containing biocarriers have been successful by far with few limitations. The impact of bio-carrier materials type and properties on wastewater treatment is one important aspect that needs attention. Different synthetic materials have been utilized. However, this study utilized waste palm oil clinker (POC) as a biocarrier in a sequencing batch reactor (SBR) for syntheticdomestic wastewater treatment. This is to work in line with the attainment of sustainable development goals (SDGs). In this study, the POC was used as a biocarrier submerged in the aeration tank of bioreactor A of an attached growth system. Whereas the bioreactor B acts as a control. The overall working volume of the bioreactor systems was 10 L each. The treatment efficiency was measured by differing the hydraulic retention time (HRT) while organic contaminants were monitored. The HRT was varied at 6, 12, 24, 48, and 72 hours with the organic loading rate (OLR) kept constant at 550 mg/L.d. At all conditions of HRT (6–72 hours), minimum and maximum COD removals were up to 80% and 95.4% respectively. The influence of HRT was found to be more affected. Several biokinetic models, that includes the First order and Stover-Kincannon, were fitted to the steady-state data collected at different HRTs. The COD R2 values of 0.9096 and 0.9269 were obtained for reactors A and B, respectively. The maximum removal rate constant (μmax) and the saturation value constant (KB) for the Stover-Kincannon, were observed as 0.0005 g/L.d and 1 g/L.d, respectively for the bioreactor A. Throughout the study, POC incorporated SBR system demonstrated higher treatment efficiency compared to the control reactor in terms of COD removal. Thus, findings from this study have the potential to answer SDGs 6, 9, and 14.

Background: Toxicokinetics of nanomaterials, including studies on the absorption, distribution, metabolism, and elimination of nanomaterials, are essential in assessing their potential health effects. The fate of nanomaterials after inhalation exposure to multiple nanomaterials is not clearly understood. Methods: Male Sprague–Dawley rats were exposed to similar sizes of silver nanoparticles (AgNPs, 10.86 nm) and gold nanoparticles (AuNPs, 10.82 nm) for 28 days (6-h/day, 5-days/week for four weeks) either with separate NP inhalation exposures or with combined co-exposure in a nose-only inhalation system. Mass concentrations sampled from the breathing zone were AuNP 19.34 ± 2.55 μg/m3 and AgNP 17.38 ± 1.88 μg/m3 for separate exposure and AuNP 8.20 μg/m3 and AgNP 8.99 μg/m3 for co-exposure. Lung retention and clearance were previously determined on day 1 (6-h) of exposure (E-1) and on post-exposure days 1, 7, and 28 (PEO-1, PEO-7, and PEO-28, respectively). In addition, the fate of nanoparticles, including translocation and elimination from the lung to the major organs, were determined during the post-exposure observation period. Results: AuNP was translocated to the extrapulmonary organs, including the liver, kidney, spleen, testis, epididymis, olfactory bulb, hilar and brachial lymph nodes, and brain after subacute inhalation and showed biopersistence regardless of AuNP single exposure or AuNP + AgNP co-exposure, showing similar elimination half-time. In contrast, Ag was translocated to the tissues and rapidly eliminated from the tissues regardless of AuNP co-exposure. Ag was continually accumulated in the olfactory bulb and brain and persistent until PEO-28. Conclusion: Our co-exposure study of AuNP and AgNP indicated that soluble AgNP and insoluble AuNP translocated differently, showing soluble AgNP could be dissolved into Ag ion to translocate to the extrapulmonary organs and rapidly removed from most organs except the brain and olfactory bulb. Insoluble AuNPs were continually translocated to the extrapulmonary organs, and they were not eliminated rapidly. [ABSTRACT FROM AUTHOR]

Heavy metal Zinc is still a pollutant from various industrial and domestic activities whose waste is directly dumped into the waters. The presence of biota in the waters can be used as a bioindicator to identify the presence of heavy metal contaminants. The kinetics of the Zinc bioaccumulation process through the freshwater route using pomfret (Colossoma macropomum) and sepat fish (Trichogaster trichopterus) as bioindicators have been investigated by analyzing the effect on variations in concentration and pH. This research was conducted by determining Zinc speciation's effect and concentration on the bioaccumulation process. The results showed an increase in concentration would also increase the rate of uptake and elimination rate of Zinc by pomfret and sepat, obtained concentration factors (CF) at variations of Zinc concentration in pomfret was 2.56 - 22.97 mL.g-1 and 2.14 - 56.87 mL.g-1 in sepat fish. While the value of the concentration factor (CF) in the variation of pH for pomfret is 0.65 - 13.15 mL.g-1 and for sepat fish is 0.93 - 15.29 mL.g-1, and ZnCl42- was the dominant species containing Zn in most of the electrolytes in fresh water and from each concentration variation. This method is expected to provide information that can be used for environmental studies and against toxic effects for food safety. [ABSTRACT FROM AUTHOR]

In radionuclide therapy, activity kinetics in tissues determine the absorbed doses administered and thus efficacy and side effects of treatment. The objective of this work was to derive expressions for the parameters affecting the absorbed dose to a target tissue for first-order activity kinetics. The activity uptake results from contributions from the first-pass activity flow through the target tissue preceding systemic equilibration and uptake after distribution of the administered compound in the body. The absorbed dose from uptake after equilibration is the product of the mean energy deposited per decay in the target tissue, the time integral of the plasma activity concentration, the plasma volume flow per unit target tissue mass, the probability of activity removal during passage, and the mean lifetime of activity in the target tissue. Quantitative analysis of the determinants of absorbed dose exemplarily for radioiodine therapy indicates that the high uptake often observed in Graves' disease must be associated with high tissue perfusion and removal probability and that administration of stable iodine increases mean lifetime. For therapies with long residence times of the active compound in the blood, such as radioiodine therapy, the contribution of the first-pass is small compared with uptake after equilibration. The relative first-pass contribution is higher for agents that are rapidly eliminated from the blood pool, such as radiolabelled somatostatin analogues, and may dominate after arterial application. Understanding the determining parameters in radionuclide therapy reveals dose-limiting factors and opens up opportunities to optimise and individualize therapy, potentially improving treatment success rates. [ABSTRACT FROM AUTHOR]

The hard-shell mussels Mytilus coruscus have been extensively employed in pollution biomonitoring. Earlier studies indicated that metal concentrations in Mytilus coruscus may not accurately reflect the true metal contamination levels in the sampling areas, possibly due to their modified metal uptake and efflux. Given the likelihood of mussels in the field being exposed to intermittent metal contaminants, this study investigated whether different Cu pre-exposures significantly affected its uptake and efflux upon Cu exposure. We found significant reduction in Cu uptake rate constant (k u) and efflux rate constant (k e) in the mussels with varying Cu pre-exposure regimes. Specifically, the k u decreased from 1.55 ± 0.37 L g−1 d−1 in the control group to 0.65 ± 0.19 after 5 days and 0.53 ± 0.28 after 15 days of exposure to 20 μg L−1 Cu, respectively, and then was further reduced to as low as 0.096 ± 0.046 L g−1 d−1 following a 5-day exposure at 50 μg L−1 Cu. Similarly, the k e decreased from 0.18 ± 0.020 to 0.15 ± 0.015 d−1 following 5–15 days of exposure to 20 μg L−1 Cu, and further decreased to 0.081 ± 0.023 d−1 after a 5-day exposure at 50 μg L−1 Cu. Our subcellular distribution analysis underscored the critical role of the metallothionein-like protein (MTLP) fraction in modifying both Cu k u and k e during the rapid-depuration phase (k e1), whereas the metal-rich granule (MRG) fraction influenced the k e during the second depuration phase (k e2). This study demonstrated that environmental assessments utilizing biomonitoring species should consider the exposure of these organisms to ensure accurate interpretations of metal contamination in marine ecosystems and enhance the effectiveness of these species in environmental monitoring. This crucial factor is often overlooked, potentially skewing data and leading to misinterpretations of environmental health and pollution levels. [Display omitted] • Pre-exposure to Cu reduces the uptake and efflux rates of Cu in hard-shell mussels. • Pre-exposure to Cu alters Cu accumulation capacities in hard-shell mussels. • Metal pollution biomonitoring should consider organisms' pre-exposure history. • MTLP are associated with Cu uptake and rapid-efflux rates in hard-shell mussels. • MRG are associated with Cu second-efflux rates in hard-shell mussels. [ABSTRACT FROM AUTHOR]

Background: The rehabilitative nature of biokinetics and physiotherapy in osteoarthritis management highlights a complex interaction between different professions to achieve effective outcomes for the patient. The success of a team approach is dependent on key competencies for optimal patient-focused care and appropriate cross-referral systems. Objectives: To explore and describe the viewpoints of biokineticists and physiotherapists regarding a team approach to osteoarthritis management in the South African public and private healthcare setting. Methods: A descriptive methodology with a convenience sampling technique was used. The target population consisted of biokineticists (n=47) and physiotherapists (n=165) located within the South African healthcare sectors. A selfadministered, online questionnaire surveyed rehabilitative professionals’ views of a team approach to osteoarthritis management. Results: There is no evidence that the biokineticists and physiotherapists differ with respect to how they rate the communication between team members in osteoarthritis management (p=0.68). Communication was viewed as neither of a high nor low quality by biokineticists (43%) and physiotherapists (36%). Biokineticists (54%) and physiotherapists (69%) felt adequately equipped on their understanding of the role of various healthcare professions involved in osteoarthritis management (p=0.22). However, 43% of rehabilitative professionals indicated that they had not been exposed to interprofessional education initiatives (p=0.61). Conclusion: Both professions were well-versed on the roles of various professions involved in osteoarthritis management, however, communication was not optimal. While this study creates an awareness of the benefits of team-based management for osteoarthritis, the findings could stimulate debate on the optimal implementation of key competencies required for effective teamwork, thereby facilitating patientfocused care and referral systems. [ABSTRACT FROM AUTHOR]

A mathematical model for estimating the characteristics of the process of thermal inactivation of vegetative bacterial cells and their spores is presented. The model relates the change rate of the number of living cells as a nonlinear kinetic dependence of the p-th order, and the temperature constant of their inactivation rate is the Arrhenius function. A method for solving the inverse kinetic problem of identifying the parameters of this model from experimental data is proposed. The method is implemented through the minimization of the original functional, which reduces the number of variable parameters. The solution results of inverse problems for determining the kinetic model parameters based on the experimental data of thermal inactivation of bacterial spores B. subtilis and B. anthracis are presented. The obtained parameters are used to solve the direct problems of the dynamics of micro-organism inactivation. The calculation results represent the dependence on the time of the change number of inactivated micro-organisms, and the thermal exposure time for 99% of their deaths at different temperatures. A comparison of the results with other authors' calculations and experimental data confirms the adequacy of the model, the high accuracy of the new solution method and the algorithm for its implementation. The developed model of thermal sterilization can be used for the selective deactivation of pathogens in the food products. [ABSTRACT FROM AUTHOR]

The practice of Recreational Therapy/Therapeutic recreation (RT/TR) in South Africa (SA) is currently unrecognized, and whether some of the existing health professions in SA are providing services like those of RT/TR, as practised in the United States of America, is unclear. Biokinetics, physiotherapy and occupational therapy are the three professions currently registered with the Health Professions Council of South Africa with similarities in their definitions of scopes of practice to the definition of RT/TR. A qualitative interpretive descriptive study-design was followed, consisting of thematic analysis of 30 semi-structured telephonic interviews, which were conducted with biokineticists, physiotherapists and occupational therapists in private practice. Data analysis resulted in the identification of three themes. Although functional intervention programmes are presented by biokineticists, physiotherapists and occupational therapists, their programmes could not be classified as RT/TR orientated. There is a gap that could be filled by RT/TR in SA, in terms of the provision of leisure education and recreation participation programmes. This study provides information about the services available and identifies the gaps in the services of the three healthcare professions. The study concludes with a proposed continuum that indicates which services are currently provided and where RT/TR can fit into the current healthcare sector. [ABSTRACT FROM AUTHOR]

In South Africa (SA), recreational therapy (RT)/therapeutic recreation (TR) as profession ended in June 1978 and currently remains unrecognized as a profession. Some of the existing health professions in SA may provide services similar to those of RT/TR as practised in the United States of America (USA). In particular, the scopes of practice of biokinetics (a SA profession similar to clinical exercise physiology), physiotherapy and occupational therapy show some similarities to the international concept of RT/TR. The study aimed to interpret and describe RT/TR, as practised in the USA, within the curricula of biokinetics, physiotherapy and occupational therapy. The credentialing document for the speciality of RT/TR published by the US National Council for Therapeutic Recreation Certification: Certification Standards: Information for New Applicants, 2018 was subjected to inductive content analysis, followed by a deductive analysis of the biokinetics, physiotherapy and occupational therapy curricula detailed in the yearbooks of seven SA universities. Some similarities were observed between the requirements of RT/TR in the USA and biokinetics, physiotherapy and occupational therapy curricula, especially in terms of foundational knowledge. However, knowledge about recreation, specifically RT/TR, was lacking from the biokinetics, physiotherapy and occupational therapy curricula, suggesting that RT/TR is not featured in them. [ABSTRACT FROM AUTHOR]

Background: Head-loading, as a mode of transporting food, water and firewood, is a longstanding tradition assigned to female South African youth and has been associated with adverse health consequences. Objectives: This study determined the impact of head-loading on the neuromusculoskeletal health and proprioception of female South African youth. Method: This study comprised a counterbalanced, within-subject, single-factor experimental design which compared the changes that occurred when the same independent variable (head-loading) within two homogenous groups was measured in terms of the dependent variables (outcomes: neuromusculoskeletal pain and proprioception) at two time periods, before and after the introduction of the independent variable. A cohort of South African female youth (n = 100), aged 9–17 years, voluntarily partook in the study. The participants were randomly distributed into an experimental (n = 50) and a control (n = 50) group. The experimental group stood in a head-loaded state with their respective habitual head-load mass. Their proprioception measurements were compared during their unloaded versus loaded states, with the proprioceptive measurements including the total proprioception index, the anterior–posterior (front–back) index and the medial–lateral (side-to-side) index. Participants furthermore completed a head-loading health-related questionnaire. Results: Participants had a mean age of 12.3 ± 2.5 years, body mass of 44.4 ± 13.7 kg, stature of 145 ± 10 cm and a head-load mass of 8.0 ± 2.5 kg. Participants had poorer medial–lateral proprioception during head-loading as compared to their unloaded state (1.4 ± 0.8 as compared to 1.6 ± 0.9) (p 0.05). Most youth (96%) experienced neuromusculoskeletal pain in their cervical vertebrae (40.9%), shoulders (27.3%), lumbar vertebrae (10.7%), arms (8.3%), legs (8.3%), knees (1.9%), fingers (1.5%), toes (0.5%) and thoracic vertebrae (0.5%) (χ2: p 0.05). Conclusion: Head-loading adversely affects the medial–lateral proprioception and neuromusculoskeletal health of participants. Contribution: The findings of this study confirms that head-loading produces musculoskeletal pain.

Decommissioning fission and fusion facilities can result in the production of airborne particles containing tritium that could inadvertently be inhaled by workers directly involved in the operations, and potentially others, resulting in internal exposures to tritium. Of particular interest in this context, given the potentially large masses of material involved, is tritiated steel. The International Commission on Radiological Protection (ICRP) has recommended committed effective dose coefficients for inhalation of some tritiated materials, but not specifically for tritiated steel. The lack of a dose coefficient for tritiated steel is a concern given the potential importance of the material. To address this knowledge gap, a "dissolution" study, in vivo biokinetic study in a rodent model (1 MBq intratracheal instillation, 3-month follow-up) and associated state-of-the-art modelling were undertaken to derive dose coefficients for model tritiated steel particles. A committed effective dose coefficient for the inhalation of 3.3 × 10−12 Sv Bq−1 was evaluated for the particles, reflecting an activity median aerodynamic diameter (AMAD) of 13.3 µm, with the value for a reference AMAD for workers (5 µm) of 5.6 × 10−12 Sv Bq−1 that may be applied to occupational inhalation exposure to tritiated steel particles. [ABSTRACT FROM AUTHOR]

The bioluminescence activity and biokinetics of a recombinant Pseudomonas putida mt-2 were investigated in the presence of various inducers: three chlorotoluenes (CTs) and two nitrotoluenes (NTs). The effects of binary mixtures (40 combinations) of eleven inducers on the bioluminescence activity were also studied. Different responses and toxicities were observed depending on the type of inducers and concentrations. The intensity of the bioluminescent response at 1 mM of individual inducers was in the following order: o-CT > p-CT > m-CT > o-NT and p-NT. The biokinetics calculated based on the bioluminescence activity was in the range of 0.109–8.417 mM for the half-saturation constant (Ks) and 6.083–19.880 h−1 for the maximum SBR (µmax). In the case of binary mixtures, the observed bioluminescence was 4–810% (avg. 80.4%) of the expected bioluminescence intensity depending on the combinations (0.0001 < p < 0.5226). Among these binary mixture combinations, 27 out of 40 combinations indicated antagonistic effects (3–83% of expected activity; p < 0.0391) under the exposure of inducer mixtures. Overall, this study demonstrated that the proper biomonitoring for specific chemicals could be established by considering the characteristics of mixture pollutants for their possible usages as a preliminary rapid and field analytical bio-tool.

Americium-241 whole body and internal biokinetics were experimentally investigated in the euryhaline diamond sturgeon Acipenser gueldenstaedtii during its uptake from water and food, in fresh (FW) and brackish water (BW; 9 psu). Whole-body uptake rates of 241Am from water and subsequent depuration rates were quantified over 14 and 28 days, respectively, and assimilation efficiency (AE) of 241Am from diet (chironomid) was determined over 28 days. FW reduced the biological half-life of 241Am following aqueous uptake by an order of magnitude. In contrast BW greatly reduced 241Am assimilation efficiency (AE) from diet (chironomid) by several orders of magnitude (from an AE of 8.5% (FW) down to 0.003% (BW)). Hence, salinity per se is indicated as a major environmental variable in determining the radiological exposure of A. gueldenstaedtii to 241Am. During aqueous exposure BW appreciably increased 241Am activity concentrations in most body components, but aqueous or dietary exposure pathway at either salinity did not determine marked differences in how 241Am was distributed among six body components. The highly mineralized skin of A. gueldenstaedtii recurred as a major repository of 241Am in all experimental treatments, as high as 50% among body components, due to its internal transfer from diet, surface adsorption and/or active absorption from water. The indicated prominence of the aqueous, compared to the dietary, exposure pathway for 241Am accumulation by A. gueldenstaedtii suggests its radiological exposure would be enhanced by BW as it leads to its greater long-term retention, due to a much longer biological half-life. [Display omitted] • 241Am biokinetics in diamond sturgeon in fresh and brackish water. • Fresh water reduced biological half-life of 241Am following aqueous uptake. • Brackish water greatly reduced 241Am assimilation efficiency from diet. • The highly mineralized skin recurred as a major repository of 241Am. • 241Am exposure generally enhanced by salinity due to greater long-term retention. [ABSTRACT FROM AUTHOR]

Element-specific biokinetic models are used to reconstruct doses to systemic tissues from internal emitters. Typically, a systemic model for a radionuclide explicitly depicts only its dominant repositories. Remaining tissues and fluids are aggregated into a pool called Other tissue in which the radionuclide is assumed to be uniformly distributed. In the systemic biokinetic models used in radiation protection, the brain usually is addressed as an implicit mass fraction of Other tissue rather than an explicitly depicted repository. Due to increasing interest in radiation effects on the brain, efforts are underway to improve brain dosimetry for internal radiation sources. We assessed potential improvements in brain dosimetry for internal emitters by explicitly modeling brain kinetics rather than treating the brain as a mass fraction of Other tissue. We selected 10 elements for which brain kinetics can be modeled using published biokinetic data. Injection dose coefficients were calculated for a relatively long-lived radioisotope of each element using each of two versions of the ICRP's latest systemic biokinetic model for the element, the original version and a modified version differing only in the treatment of brain. If the ICRP model contained an explicit brain pool, the modified version depicted brain instead as a mass fraction of Other tissue. If the ICRP model included brain in Other tissue, the modified version included an explicit brain pool with kinetics based on best available brain-specific data. The result for a given radionuclide is expressed as a ratio A:B, where A and B are the dose coefficients based on the versions of the model with and without an explicit brain pool, respectively. The following ratios A:B were obtained for the 10 radionuclides addressed here: 241Am, 0.13; 207Bi, 0.57; 234U, 0.81; 239Pu, 0.96; 203Hg (vapor), 1.4; 134Cs, 1.5; 54Mn, 1.7; 210Po, 1.7; 226Ra, 1.9; 210Pb, 3.3. These ratios indicate that a dose estimate for brain based on a biokinetic model with brain implicitly contained in Other tissue may substantially underestimate or substantially overestimate a dose estimate that reflects best available brain-specific biokinetic data. Of course, the reliability of the latter estimate depends on the quality of the underlying biokinetic data. Where feasible, the brain should be depicted explicitly in biokinetic models used in epidemiological studies addressing adverse effects of ionizing radiation. [ABSTRACT FROM AUTHOR]

Purpose: We present here a Zr-89-labeled inhibitor of prostate-specific membrane antigen (PSMA) as a complement to the already established F-18- or Ga-68-ligands. Procedures: The precursor PSMA-DFO (ABX) was used for Zr-89-labeling. This is not an antibody, but a peptide analogue of the precursor for the production of [177Lu]Lu-PSMA-617. The ligand [89Zr]Zr-PSMA-DFO was compared with [68Ga]Ga-PSMA-11 and [18F]F-JK-PSMA-7 in vitro by determination of the Kd value, cellular uptake, internalization in LNCaP cells, biodistribution studies with LNCaP prostate tumor xenografts in mice, and in vivo by small-animal PET imaging in LNCaP tumor mouse models. A first-in-human PET was performed with [89Zr]Zr-PSMA-DFO on a patient presenting with a biochemical recurrence after brachytherapy and an ambiguous intraprostatic finding with [18F]F-JK-PSMA-7 but histologically benign cells in a prostate biopsy 7 months previously. Results: [89Zr]Zr-PSMA-DFO was prepared with a radiochemical purity ≥ 99.9% and a very high in vitro stability for up to 7 days at 37 °C. All radiotracers showed similar specific cellular binding and internalization, in vitro and comparable tumor uptake in biodistribution experiments during the first 5 h. The [89Zr]Zr-PSMA-DFO achieved significantly higher tumor/background ratios in LNCaP tumor xenografts (tumor/blood: 309 ± 89, tumor/muscle: 450 ± 38) after 24 h than [68Ga]Ga-PSMA-11 (tumor/blood: 112 ± 57, tumor/muscle: 58 ± 36) or [18F]F-JK-PSMA-7 (tumor/blood: 175 ± 30, tumor/muscle: 114 ± 14) after 4 h (p < 0.01). Small-animal PET imaging demonstrated in vivo that tumor visualization with [89Zr]Zr-PSMA-DFO is comparable to [68Ga]Ga-PSMA-11 or [18F]F-JK-PSMA-7 at early time points (1 h p.i.) and that PET scans up to 48 h p.i. clearly visualized the tumor at late time points. A late [89Zr]Zr-PSMA-DFO PET scan on a patient with biochemical recurrence (BCR) had demonstrated intensive tracer accumulation in the right (SUVmax 13.25, 48 h p.i.) and in the left prostate lobe (SUV max 9.47), a repeat biopsy revealed cancer cells on both sides. Conclusion: [89Zr]Zr-PSMA-DFO is a promising PSMA PET tracer for detection of tumor areas with lower PSMA expression and thus warrants further clinical evaluation. [ABSTRACT FROM AUTHOR]

The study investigated the effect of hydrodynamic conditions on the formation of enhanced biological phosphorus removal (EBPR) granular sludge without losing the EBPR capacity, and its structure. The effect of hydrodynamic conditions on the formation of EBPR granular sludge was evaluated by using the minimum settling velocity, (Vs)min, and superficial air velocity. The application of (Vs)min strategy was proved to be beneficial in maintaining granular biomass without losing the EBPR capacity. Microscale structure, the chemical composition and chemically stored phosphorus of the matured EBPR granular sludge were determined by using ESEM‐EDX and cold perchloric acid (PCA) analyses. The results of both the ESEM‐EDX and PCA analyses proved that the poly‐P granules were stored extracellular in EPS structure of EBPR granular sludge. Therefore, the EBPR granular sludge has a high potential for both removal and recovery of phosphorus from wastewater, which needs to be investigated in future studies. [ABSTRACT FROM AUTHOR]

Background: Blood flow restriction (BFR) training uses a cuff to partially occlude venous blood flow and improve musculoskeletal training outcomes. Over the past 25 years, numerous studies have demonstrated its relative safety and efficacy. Objectives: Blood flow restriction training is under review by the Health Professions Council of South Africa due to safety and ethical concerns. The objective of this roundtable discussion is to gain better insight into the current use and perception of blood flow restriction training in South Africa. Formation of panel: The expert panel had experience with the use of BFR training and included one representative from each of the following professions, namely, sports medicine, physiotherapy and biokinetics. Discussion: The panellists provided their unique perspectives on BFR training, whilst reaching a relative consensus on its safety, screening, efficacy, and appropriate use. Agreement on appropriate loading and occlusion pressure protocols during different phases of rehabilitation was less clear. Conclusion: Although BFR is a safe and effective modality, the development of evidence-based protocols among different health professionals in South Africa is required to ensure good clinical practice. [ABSTRACT FROM AUTHOR]

Background: Head-loading, as a mode of transporting food, water and firewood, is a longstanding tradition assigned to female South African youth and has been associated with adverse health consequences. Objectives: This study determined the impact of head-loading on the neuromusculoskeletal health and proprioception of female South African youth. Method: This study comprised a counterbalanced, within-subject, single-factor experimental design which compared the changes that occurred when the same independent variable (head-loading) within two homogenous groups was measured in terms of the dependent variables (outcomes: neuromusculoskeletal pain and proprioception) at two time periods, before and after the introduction of the independent variable. A cohort of South African female youth (n = 100), aged 9–17 years, voluntarily partook in the study. The participants were randomly distributed into an experimental (n = 50) and a control (n = 50) group. The experimental group stood in a head-loaded state with their respective habitual head-load mass. Their proprioception measurements were compared during their unloaded versus loaded states, with the proprioceptive measurements including the total proprioception index, the anterior–posterior (front–back) index and the medial–lateral (side-to-side) index. Participants furthermore completed a head-loading health-related questionnaire. Results: Participants had a mean age of 12.3 ± 2.5 years, body mass of 44.4 ± 13.7 kg, stature of 145 ± 10 cm and a head-load mass of 8.0 ± 2.5 kg. Participants had poorer medial–lateral proprioception during head-loading as compared to their unloaded state (1.4 ± 0.8 as compared to 1.6 ± 0.9) (p < 0.05). Most youth (96%) experienced neuromusculoskeletal pain in their cervical vertebrae (40.9%), shoulders (27.3%), lumbar vertebrae (10.7%), arms (8.3%), legs (8.3%), knees (1.9%), fingers (1.5%), toes (0.5%) and thoracic vertebrae (0.5%) (χ2: p < 0.05). Conclusion: Head-loading adversely affects the medial–lateral proprioception and neuromusculoskeletal health of participants. Contribution: The findings of this study confirms that head-loading produces musculoskeletal pain. [ABSTRACT FROM AUTHOR]

A mathematical model for estimating the characteristics of the process of thermal inactivation of vegetative bacterial cells and their spores is presented. The model relates the change rate of the number of living cells as a nonlinear kinetic dependence of the p-th order, and the temperature constant of their inactivation rate is the Arrhenius function. A method for solving the inverse kinetic problem of identifying the parameters of this model from experimental data is proposed. The method is implemented through the minimization of the original functional, which reduces the number of variable parameters. The solution results of inverse problems for determining the kinetic model parameters based on the experimental data of thermal inactivation of bacterial spores B. subtilis and B. anthracis are presented. The obtained parameters are used to solve the direct problems of the dynamics of micro-organism inactivation. The calculation results represent the dependence on the time of the change number of inactivated micro-organisms, and the thermal exposure time for 99% of their deaths at different temperatures. A comparison of the results with other authors’ calculations and experimental data confirms the adequacy of the model, the high accuracy of the new solution method and the algorithm for its implementation. The developed model of thermal sterilization can be used for the selective deactivation of pathogens in the food products.

Purpose: One therapy option for prostate cancer patients with bone metastases is the use of [223Ra]RaCl2. The α-emitter 223Ra creates DNA damage tracks along α-particle trajectories (α-tracks) in exposed cells that can be revealed by immunofluorescent staining of γ-H2AX+53BP1 DNA double-strand break markers. We investigated the time- and absorbed dose-dependency of the number of α-tracks in peripheral blood mononuclear cells (PBMCs) of patients undergoing their first therapy with [223Ra]RaCl2. Methods: Multiple blood samples from nine prostate cancer patients were collected before and after administration of [223Ra]RaCl2, up to 4 weeks after treatment. γ-H2AX- and 53BP1-positive α-tracks were microscopically quantified in isolated and immuno-stained PBMCs. Results: The absorbed doses to the blood were less than 6 mGy up to 4 h after administration and maximally 16 mGy in total. Up to 4 h after administration, the α-track frequency was significantly increased relative to baseline and correlated with the absorbed dose to the blood in the dose range < 3 mGy. In most of the late samples (24 h – 4 weeks after administration), the α-track frequency remained elevated. Conclusion: The γ-H2AX+53BP1 assay is a potent method for detection of α-particle-induced DNA damages during treatment with or after accidental incorporation of radionuclides even at low absorbed doses. It may serve as a biomarker discriminating α- from β-emitters based on damage geometry. [ABSTRACT FROM AUTHOR]

Decommissioning fission and fusion facilities can result in the production of airborne particles containing tritium that could inadvertently be inhaled by workers directly involved in the operations, and potentially others, resulting in internal exposures to tritium. Of particular interest in this context, given the potentially large masses of material involved, is tritiated steel. The International Commission on Radiological Protection (ICRP) has recommended committed effective dose coefficients for inhalation of some tritiated materials, but not specifically for tritiated steel. The lack of a dose coefficient for tritiated steel is a concern given the potential importance of the material. To address this knowledge gap, a “dissolution” study, in vivo biokinetic study in a rodent model (1 MBq intratracheal instillation, 3-month follow-up) and associated state-of-the-art modelling were undertaken to derive dose coefficients for model tritiated steel particles. A committed effective dose coefficient for the inhalation of 3.3 × 10−12 Sv Bq−1 was evaluated for the particles, reflecting an activity median aerodynamic diameter (AMAD) of 13.3 µm, with the value for a reference AMAD for workers (5 µm) of 5.6 × 10−12 Sv Bq−1 that may be applied to occupational inhalation exposure to tritiated steel particles.

Purpose: The radiolabelled somatostatin analogue [177Lu]Lu-DOTA-EB-TATE binds to albumin via Evans blue, thereby increasing the residence time in the blood and potentially allowing more therapeutic agent to be absorbed into the target tissue during peptide receptor radionuclide therapy. It was tested in selected patients whether the substance is superior to [177Lu]Lu-DOTA-TOC. Methods: Activity kinetics in organs and tumours after [177Lu]Lu-DOTA-EB-TATE and [177Lu]Lu-DOTA-TOC were compared intraindividually in five patients with progressive somatostatin receptor-positive disease scheduled for radionuclide therapy. Results: In comparison to [177Lu]Lu-DOTA-TOC, tumour doses per administered activity were higher for [177Lu]Lu-DOTA-EB-TATE in 4 of 5 patients (median ratio: 1.7; range: 0.9 to 3.9), kidney doses (median ratio: 3.2; range: 1.6 to 9.8) as well as spleen doses (median ratio: 4.7; range 1.2 to 6.2) in all patients, and liver doses in 3 of 4 evaluable patients (median ratio: 4.0; range: 0.7 to 4.9). The tumour to critical organs absorbed dose ratios were higher after [177Lu]Lu-DOTA-TOC in 4 of 5 patients. Conclusions: Prior to a treatment with [177Lu]Lu-DOTA-EB-TATE, it should be assessed individually whether the compound is superior to established substances. [ABSTRACT FROM AUTHOR]

Bathroom greywater represent the major portion of the total greywater production from the household activity. These wastes should be subjected to a treatment process before being discharged directly into the environment to avoid the occurrence of the eutrophication phenomenon. Hence, the current work aimed to investigate the potential of phycoremediation process for removing nutrients from artificial bathroom greywater (ABGW) by Botryococcus sp. The phycoremediation process was conducted for 30 d, while the microalgae cell growth in ABGW was measured daily. The biokinetic absorption using Michaelis-Menten were determined for NO3-N and PO4-P. The results revealed that the maximum microalgae cell growth was recorded on the 10th day with 2.0 × 106 cells/mL. The highest removal of NO3-N (97%) and PO4-P (87%) were achieved on the 30th day of phycoremediation. The biokinetic absorption rate using Michaelis-Menten coefficient were K = 0.265 mg NO3-N mg/Chl-a/d and Km = 2.38 mg/L, while for PO4-P were K = 1.057 mg PO4-P mg/Chl-a/d and Km = 12.04 mg/L. In conclusion, phycoremediation using Botryococcus sp. exhibited a high potential for the nutrients removal from ABGW. [ABSTRACT FROM AUTHOR]