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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]

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.

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]

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.

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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]

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]

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]

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]

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.

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]

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]

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.

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.

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]

Considerable progress has been made in various fields of applied research on the use of carbon nanotubes (CNTs). Because CNTs are fibrous nanomaterials, biosafety of CNTs has been discussed. The biokinetic data of CNTs, such as using the radioisotope of carbon and surface labeling of CNTs, have been reported. However, the use of radioisotopes requires a special facility. In addition, there are problems in the surface labeling of CNTs, including changes in surface properties and labels eliminating over time. In order to solve these problems and properly evaluate the biokinetics of CNTs, the authors synthesize peapods with platinum (Pt) encapsulated within the hollow region of Double-Walled CNTs (DWCNTs) and develop a new system to evaluate biokinetics using widely available imaging equipment. In the cell assay, no significant difference is observed with and without Pt in CNTs. In animal studies, radiography of the lungs of rats that inhaled Pt-peapods show the detectability of Pt inside the CNTs. This new method using Pt-peapods enables image evaluation with a standard radiographic imaging device without changing the surface property of the CNTs and is effective for biokinetics evaluation of CNTs.

Abstract Background Renal scans are among the most frequent exams performed on infants and toddlers. Due to the young age, this patient group can be classified as a high-risk group with a higher probability for developing stochastic radiation effects compared to adults. As there are only limited data on biokinetics and dosimetry in this patient group, the aim of this study was to reassess the dosimetry and the associated radiation risk for infants undergoing 99mTc-MAG3 renal scans based on a retrospective analysis of existing patient data. Consecutive data were collected from 20 patients younger than 20 months (14 males; 6 females) with normal renal function undergoing 99mTc-MAG3 scans. To estimate the patient-specific organ activity, a retrospective calibration was performed based on a set of two 3D-printed infant kidneys filled with known activities. Both phantoms were scanned at different positions along the anteroposterior axis inside a water phantom, providing depth- and size-dependent attenuation correction factors for planar imaging. Time-activity curves were determined by drawing kidney, bladder, and whole-body regions-of-interest for each patient, and subsequently applying the calibration factor for conversion of counts to activity. Patient-specific time-integrated activity coefficients were obtained by integrating the organ-specific time-activity curves. Absorbed and effective dose coefficients for each patient were assessed with OLINDA/EXM for the provided newborn and 1-year-old model. The risk estimation was performed individually for each of the 20 patients with the NCI Radiation Risk Assessment Tool. Results The mean age of the patients was 7.0 ± 4.5 months, with a weight between 5 and 12 kg and a body size between 60 and 89 cm. The injected activities ranged from 12 to 24 MBq of 99mTc-MAG3. The patients’ organ-specific mean absorbed dose coefficients were 0.04 ± 0.03 mGy/MBq for the kidneys and 0.27 ± 0.24 mGy/MBq for the bladder. The mean effective dose coefficient was 0.02 ± 0.02 mSv/MBq. Based on the dosimetry results, an evaluation of the excess lifetime risk for the development of radiation-induced cancer showed that the group of newborns has a risk of 16.8 per 100,000 persons, which is about 12% higher in comparison with the 1-year-old group with 14.7 per 100,000 persons (all values are given as mean plus/minus one standard deviation except otherwise specified). Conclusion In this study, we retrospectively derived new data on biokinetics and dosimetry for infants with normal kidney function after undergoing renal scans with 99mTc-MAG3. In addition, we analyzed the associated age- and gender-specific excess lifetime risk due to ionizing radiation. The radiation-associated stochastic risk increases with the organ doses, taking age- and gender-specific influences into account. Overall, the lifetime radiation risk associated with the 99mTc-MAG3 scans is very low in comparison to the general population risk for developing cancer.

Pharmacokinetic modeling of the radiopharmaceuticals used in molecular radiotherapy is an important step towards accurate radiation dosimetry of such therapies. In this paper, we present a pharmacokinetic model for CLR1404, a phospholipid ether analog that, labeled with 124I/131I, has emerged as a promising theranostic agent. We follow a systematic approach for the model construction based on a decoupling process applied to previously published experimental data, and using the goodness-of-fit, Sobol’s sensitivity analysis, and the Akaike Information Criterion to construct the optimal form of the model, investigate potential simplifications, and study factor prioritization. This methodology was applied to previously published experimental human time-activity curves for 9 organs. The resulting model consists of 17 compartments involved in the CLR1404 metabolism. Activity dynamics in most tissues are well described by a blood contribution plus a two-compartment system, describing fast and slow uptakes. The model can fit both clinical and pre-clinical kinetic data of 124I/131I. In addition, we have investigated how simple fits (exponential and biexponential) differ from the complete model. Such fits, despite providing a less accurate description of time-activity curves, may be a viable alternative when limited data is available in a practical case.

Abstract Background We previously showed that cerium oxide (CeO2), barium sulfate (BaSO4) and zinc oxide (ZnO) nanoparticles (NPs) exhibited different lung toxicity and pulmonary clearance in rats. We hypothesize that these NPs acquire coronas with different protein compositions that may influence their clearance from the lungs. Methods CeO2, silica-coated CeO2, BaSO4, and ZnO NPs were incubated in rat lung lining fluid in vitro. Then, gel electrophoresis followed by quantitative mass spectrometry was used to characterize the adsorbed proteins stripped from these NPs. We also measured uptake of instilled NPs by alveolar macrophages (AMs) in rat lungs using electron microscopy. Finally, we tested whether coating of gold NPs with albumin would alter their lung clearance in rats. Results We found that the amounts of nine proteins in the coronas formed on the four NPs varied significantly. The amounts of albumin, transferrin and α-1 antitrypsin were greater in the coronas of BaSO4 and ZnO than that of the two CeO2 NPs. The uptake of BaSO4 in AMs was less than CeO2 and silica-coated CeO2 NPs. No identifiable ZnO NPs were observed in AMs. Gold NPs coated with albumin or citrate instilled into the lungs of rats acquired the similar protein coronas and were cleared from the lungs to the same extent. Conclusions We show that different NPs variably adsorb proteins from the lung lining fluid. The amount of albumin in the NP corona varies as does NP uptake by AMs. However, albumin coating does not affect the translocation of gold NPs across the air-blood barrier. A more extensive database of corona composition of a diverse NP library will develop a platform to help predict the effects and biokinetics of inhaled NPs.

Abstract A bioremedial approach was investigated on the removal of Cr(VI) from aqueous solution using a novel chromium reducing bacteria isolated from coalmine wastewater. Cr(VI) removal efficacy of the bacterium was determined in a series of batch studies under the influence of various parameters viz., pH (1–7), temperature (20–40 °C), initial metal concentration (1–150 mg/L), agitation speed (80–150 rpm) and substrate concentration (1–5 mg/L). Oxygen involvement in the removal process was determined by different incubation conditions. Substrate consumption and its resultant biomass generation were considered for determining the viability of the microbe under varied metal concentration. The microbial isolate survived in Cr(VI) tainted solution with initial concentration of 1–140 mg/L, among which maximum remediation was found in 60 mg/L Cr(VI) loaded solution. The bacterial species also survived in other metal solution viz., Fe(II), As(V), Cu(II), Pb(II), Zn(II), Mg(II), Mn(II) apart from Cr(VI). Multiple approaches were tested to facilitate understanding of the bacterial Cr(VI) removal mechanism. The bacteria accumulated metal ions in the exponential growth phase both on and within the cell. Underlying latent factors which governed the bacterial growth and its removal activity was determined with the classical Monod equation. The isolated bacterium also survived in the bimetallic solutions with significant removal of Cr(VI). The microbial species isolated from mining area was identified as Pseudomonas brenneri by 16s rRNA molecular characterization. Hence, the isolated novel bacterium illustrated promising involvement towards bio-treatment of Cr(VI) laden wastewater. Graphical abstract Image 1 Highlights • Cr(VI) reducing bacterium was isolated from coalmine area. • The isolate was identified as Pseudomonas brenneri by 16s rRNA characterization. • The incubation condition parameters were optimized. • Cr(VI) bioremediation efficiency was tested for both single and bimetallic solutions. • Cr(VI) bioremedial process was substantiated with Monod's equation. [ABSTRACT FROM AUTHOR]

Radioactive iodine represents the significant therapeutic option in the treatment of benign thyroid disease. Despite a decades-long experience and a large number of treated patients, many issues related to the therapy with radioactive iodine are still under discussion, including the method of therapeutic dose determination and the factors that affect the therapy outcome. Clinical practice, as well as recommendations of the relevant guidelines in terms of the dosing of radioactive iodine, vary widely in the world: from the fixed dose application to the complex dosimetric protocols. A greater presence of dosimetric approach would facilitate the establishment of dose-effect correlation and the study of influence of various factors on the therapy outcome. Development of the new dosing protocols, as well as new insights into factors that affect therapeutic outcome, enable further improvement of both efficacy and safety of the radioactive iodine therapy for an individual patient.

Development of a strategy to mitigate nitrous oxide (N 2 O) emitted from biological sources is important in the nexus of wastewater treatment and greenhouse gas emission. To this end, immobilization of N 2 O-reducing bacteria as a biofilm has the potential to ameliorate oxygen (O 2 ) inhibition of the metabolic activity of the bacteria. We demonstrated the effectiveness of calcium alginate gel entrapment of the nosZ clade II type N 2 O-reducing bacterium, Azospira sp. strain I13, in reducing levels of N 2 O, irrespective of the presence of O 2 . Azospira sp. strain I13 cells in the gel exhibited N 2 O reduction up to a maximum dissolved oxygen concentration of 100 μM in the bulk liquid. The maximum apparent N 2 O uptake rate, V m , N 2 O ′ , by gel immobilization did not appreciably decrease, retaining 72% of the N 2 O reduction rate of the cell suspension of Azospira sp. strain I13. Whereas gel immobilization increased the apparent half-saturation constant for N 2 O, K m , N 2 O ′ , and the apparent O 2 inhibition constant, K I , O 2 ′ , representing the degree of O 2 resistance, correspondingly increased. A mechanistic model introducing diffusion and the reactions of N 2 O consumption was used to describe the experimental observations. Incorporating Thieles modulus into the model determined an appropriate gel size to achieve N 2 O reduction even under aerobic conditions. [ABSTRACT FROM AUTHOR]

In the present paper, the feasibility of citrus wastewater treatment with aerobic granular sludge sequencing batch reactors (AGSBR) was investigated. Two AGSBRs (named R1 and R2, respectively) were operated for 90 days under different organic loading rates (OLR) and pH in two experimental periods. The OLR ranged approximately between 3.0 kg TCOD m −3 d −1 and 7 kg TCOD m −3 d −1 during Period I, whereas between 7 kg TCOD m −3 d −1 and 15 kg TCOD m −3 d −1 during Period II. pH was maintained at 7.0 and 5.5 in R1 and R2, respectively. The results revealed that under high OLR and unbalanced feast/famine regime (Period I), the development of fast-growing microorganisms (fungi and filamentous bacteria) was favoured in both reactors, resulting in granular sludge instability. An extended famine phase and a proper balancing between feast and famine periods (Period II) were favourable for the development of bacteria with low growth rates (0.05 d −1 ) thus enhancing the granules stability. To the benefit of granular sludge stability and effluent quality, the length of the feast period should not exceed 25% of cycle length. Moreover, under OLR lower than 7 kg TCOD m −3 d −1 the removal efficiency of total chemical oxygen demand (TCOD) was approximately 90% in R1 and R2 and no side effects on the organic carbon removal performance related to the pH were observed. In contrast, at higher OLR a significant decrease in the removal efficiency (from 90% to less than 75%) was observed in R2. Results revealed also that under low pH, hydrolysis of proteins occurred and a decrease in the biological kinetic rates proportionally to the applied OLR was observed. [ABSTRACT FROM AUTHOR]

This paper deliberates the modelling and validation of bacteriocin-like inhibitory substance (BLIS) secretion by Pediococcus acidilactici Kp10 at different agitation speeds in a stirred tank bioreactor. A range of models namely the re-parameterised logistic, Luedeking-Piret and maintenance energy were assessed to predict the culture performance of the said bacterium. Growth of P. acidilactici Kp10 was enhanced with increased agitation speed up to 600 rpm while BLIS secretion was maximum at 400 rpm but decreased at higher agitation speed. Growth of P. acidilactici aptly subscribed to the re-parameterised logistic model while BLIS secretion and lactose consumption fitted well with the Luedeking-Piret model. The models revealed a relationship between growth of the bacterium and BLIS secretion. Bacterial growth and BLIS secretion were largely affected by the agitation speed of the stirred tank bioreactor which regulated the oxygen transfer to the culture. BLIS secretion by P. acidilactici Kp10 was however enhanced in oxygen-limited culture. The study also assessed BLIS from the perspective of its stability when subjected to factors such as temperature, pH and detergents. Results showed that BLIS produced by this strain was not affected by heat (at 25-100 °C for 20 min and at 121 °C for 15 min), surfactant (Tween 40, 60 and 80 and urea), detergents (up to 1% SDS), organic solvents (50% each of acetone, methanol and ethanol) and stable in a wide range of pH (2-10). The above information are pertinent with reference to commercial applications of this bacterial product in food manufacturing which invariably involve various sterilization processes and subjected to a wide pH range. [ABSTRACT FROM AUTHOR]

In this study, an anaerobic moving bed biofilm reactor (AMBBR) was designed to biodegrade atrazine under mesophilic (32 °C) condition and then it was evaluated for approximately 1 year. After biofilm formation, acclimation, and enrichment of microbial population within the bioreactor, the effect of various operation conditions such as changes in the concentration of influent atrazine and sucrose, hydraulic retention time (HRT), and salinity on the removal of atrazine and chemical oxygen demand (COD) were studied. In optimum conditions, the maximum removal efficiency of atrazine and COD was 60.5% and 97.4%, respectively. Various models were developed to predict the performance of atrazine removal as a function of HRT during continuous digestion. Also, coefficients kinetics was studied and the maximum atrazine removal rate was determined by Stover - Kincannon model (r max = 0.223 kg ATZ /m 3 d). Increasing salinity up to 20 g/L NaCl in influent flow could inhibit atrazine biodegradation process strongly in the AMBBR reactor; whereas, the reactor could tolerate the concentrations less than 20 g/L easily. Results showed that AMBBR is feasible, easy, affordable, so suitable process for efficiently biodegrading toxic chlorinated organic compounds such as atrazine. There was no accumulation of atrazine in the biofilm and the loss of atrazine in the control reactor was negligible; this shows that atrazine removal mechanism in this system was due to co-metabolism. [ABSTRACT FROM AUTHOR]

When particles incorporated within a mammalian organism come into contact with body fluids they will bind to soluble proteins or those within cellular membranes forming what is called a protein corona. This binding process is very complex and highly dynamic due to the plethora of proteins with different affinities and fractions in different body fluids and the large variation of compounds and structures of the particle surface. Interestingly, in the case of nanoparticles (NP) this protein corona is well suited to provide a guiding vehicle of translocation within body fluids and across membranes. This NP translocation may subsequently lead to accumulation in various organs and tissues and their respective cell types that are not expected to accumulate such tiny foreign bodies. Because of this unprecedented NP accumulation, potentially adverse biological responses in tissues and cells cannot be neglected a priori but require thorough investigations. Therefore, we studied the interactions and protein binding kinetics of blood serum proteins with a number of engineered NP as a function of their physicochemical properties. Here we show by in vitro incubation tests that the binding capacity of different engineered NP (polystyrene, elemental carbon) for selected serum proteins depends strongly on the NP size and the properties of engineered surface modifications. In the following attempt, we studied systematically the effect of the size (5, 15, 80 nm) of gold spheres (AuNP), surface-modified with the same ionic ligand; as well as 5 nm AuNP with five different surface modifications on the binding to serum proteins by using proteomics analyses. We found that the binding of numerous serum proteins depended strongly on the physicochemical properties of the AuNP. These in vitro results helped us substantially in the interpretation of our numerous in vivo biokinetics studies performed in rodents using the same NP. These had shown that not only the physicochemical properties determined the AuNP translocation from the organ of intake towards blood circulation and subsequent accumulation in secondary organs and tissues but also the the transport across organ membranes depended on the route of AuNP application. Our in vitro protein binding studies support the notion that the observed differences in in vivo biokinetics are mediated by the NP protein corona and its dynamical change during AuNP translocation in fluids and across membranes within the organism.