Uptake Rate Research Articles

Increasing intraspecific diversity of wheat affects plant nutrient contents but not N recovery in the plant-soil system

Crop homogenization in conventional agriculture has been pervasive while ecology has shown positive effects of biodiversity on ecosystem functioning, that arise from complementarity/facilitation and sampling/selection effects. These effects are well documented for interspecific diversity in both natural ecosystems and agroecosystems but remain less documented at an intraspecific level, particularly for the rates of nutrient uptake by plants and nutrient losses from ecosystems. We conducted a field experiment with 88 experimental plots cultivated with 1, 2, 4 or 8 wheat varieties and 1, 2, 3 or 4 functional groups to assess the effects of the number of varietal and functional diversity of winter wheat on plant biomass production, plant nutrient contents (N, Ca, Cu, Fe, Mg, Mn, P, K, Na and Zn) and fertilizer N recovery in the plant-soil system using a 15N labeling method. We found both negative and positive effects of the number of varieties or number of functional groups on shoot Cu, Fe, Zn, Na and P contents, but no significant effects of intraspecific diversity on biomass production, N content and 15N recovery in the plant-soil system. Our results show differential responses to an increase of intraspecific diversity of wheat on the contents of several essential nutrients in plants and highlight the need to jointly analyze multiple nutrients. Our study also suggests that increasing intraspecific diversity had no overall negative effects on biomass production or N content. Using knowledge on variety functional traits to target specific complementarity mechanisms when designing variety mixtures could thus lead to a positive effect on nutrient absorption and biomass production.

A model-based approach for evaluating the effects of sludge rheology on methane production during high solid anaerobic digestion: Focusing on mass transfer resistance

Mass transfer process is vital for biochemical reactions, which is related to sludge rheology. But this inherent interaction has not yet been established for sewage sludge anaerobic digestion (AD). This work investigated the role of sludge rheology in bio-kinetics of AD. AD of sodium acetate and microcrystalline cellulose under different total solids (TS of 6.29%, 7.63%, 9.02%, 11.06%) of digested sludge was set up to identify the role of sludge rheology. Results showed that rheological properties, e.g., viscosity and viscoelasticity, increased with the increase of TS content. These resulted in negative effect on methane production of sodium acetate with lag phase increased from 0.93 d to 1.57 d, but almost no effect was observed for microcrystalline cellulose. An extended ADM1 model was developed, which revealed that enhanced sludge rheological properties increased mass diffusion resistance and reduced uptake rate of acetate. This effect can be described explicitly by mass transfer coefficient (kla_Sac). However, from the original ADM1, this effect was indistinctly lumped in apparent half-saturation coefficient (ksac). Based on the role of sludge rheology in mass transfer and bio-kinetics, it is suggested that modeling the methane production based on TS contents and sludge rheology is possible, which should be considered in giving an insight into the micro-scale phenomena (e.g. mass transport, bio-kinetics) in high solid AD.

Uptake of COVISHIELD vaccine and post-vaccination symptoms among healthcare workers at an academic primary care facility in Ghana.

Background: The emergence of the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has affected health systems globally. Although a safe, effective, and widely accessible vaccine is crucial to ending the pandemic, the results of studies on the acceptability of vaccines among healthcare workers (HCWs) globally have been conflicting. Documented post-vaccination experiences are also limited. This study describes the uptake of the first dose of the COVISHIELD vaccine and analyses the pattern of post-vaccination symptoms among HCWs in Ghana. Objective: This study sought to assess the uptake of the first dose of the COVISHIELD vaccine and analyse the pattern of post-vaccination symptoms among HCWs. Methods: A cross-sectional survey was conducted at the Korle Bu Polyclinic/ Family Medicine Department (KPFMD) of the Korle Bu Teaching Hospital, Accra, in March 2021. Survey participants (n=188) were staff of the department who completed a structured questionnaire within one week of receiving their first dose of the vaccine. The vaccine uptake rate was estimated from those who received the vaccine (n=255) as a percentage of the total staff number at the department (n=314). Results: The uptake rate of the first dose of the COVISHIELD vaccine among HCWs was 81.2% (n=255/314). The most frequently occurring post-vaccination symptoms were general malaise, headache, injection site pain and swelling, tiredness, muscle aches and fever. These symptoms were largely mild to moderate in severity and occurred mostly within 24 hours after vaccination. Of the 84.6% (n=159) respondents who reported at least one post-vaccination symptom, 77.4% (n=123) took analgesics to manage their symptoms. There was no significant association between age, sex, chronic health condition, a previous positive test for COVID-19 and experiencing post-vaccination symptoms. Conclusion: A high proportion of HCWs received the COVISHIELD vaccine in this study. The study's findings are comparable with prior studies that indicated that the vaccine is generally safe and well-tolerated. Various stakeholders in Ghana should continue to educate, reassure and encourage the population to accept the vaccine as a key intervention towards containing the pandemic.

C-end rule peptide-guided niosomes for prostate cancer cell targeting

The use of nanoformulations in drug delivery has a significant impact to increase the drug therapeutic efficacy and improve their safety in anticancer treatments. Non-ionic surfactant vesicles (NSVs), or niosomes, are a class of nanocarriers that are low-cost, physiochemical stable, and represent a promising alternative to liposomes. Tumor-penetrating C-end Rule (CendR) peptides, that target neuropilin-1 (NRP-1), a cell surface receptor commonly overexpressed on solid tumor cells, are widely used for precise delivery of diagnostic and therapeutic nanoparticles to malignant lesions. In this study, we investigated the impact of NSV functionalization with prototypic CendR peptide RPARPAR (abbr. RPAR) on NRP-1-dependent targeting of prostate cancer cells. Doxorubicin (DOX)-loaded NSVs, with or without RPAR conjugation, were prepared, physicochemical characterized, and finally tested for NRP-1 binding in human primary prostate carcinoma-1 and prostate carcinoma epithelial cell lines (PPC-1 and 22Rv1, respectively) that are NRP-1 positive, and melanoma (M21) cells that are NRP-1 negative. We demonstrated that the cellular uptake of RPAR-NSVs was NRP-1-dependent and the uptake rate of RPAR-NSVs was ca. ten times higher than un-targeted NSVs in PPC-1 cells; while no significant differences, between targeted and un-targeted nanocarriers, were obtained in M21 cell line. These data were further confirmed by using NRP-1 CendR-binding pocket-blocking (mAb7E8) antibody, which significantly inhibited the internalization of RPAR-NSVs in PPC-1 cells from ca. 80%–3%. The resulting data obtained of cytotoxic studies agreed the uptake results, thus showing a significant increase of cytotoxic effect for RPAR-NSVs@DOX in PPC-1 and 22Rv1 cells compared to NSVs@DOX. These results provide a proof of concept that the conjugation of CendR peptides on the surface of NSVs can increase the specific targeting of nanoparticles in NRP-1 positive cells, thus improving the therapeutic efficacy of resulting targeted nanocarriers for cancer treatment. Our results have important implications for the development of more efficient and selective cancer therapies and support further in vivo studies by using more complex targeting peptides, such as iRGD or other CendR peptides, that are also targeting primary recruitment receptors (i.e. integrins) and are then proteolytically activated into CendR peptides in the tumor microenvironment.

The effects of dissolved organic matter supplements on the metabolism of corals under heat stress

AbstractOctocorals represent a major alternative group in the benthic community of reefs that have diverged from hexacoral dominance. Despite their phototrophic symbionts, supplementing their diet with heterotrophic sources may promote their growth, particularly when compared to hexacorals in bleaching conditions. However, limited comprehensive data exists on octocorals' trophic ecology, especially regarding their ability to feed on dissolved organic matter (DOM), which comprises the largest pool of organic matter in reefs. This study aims to investigate the ability of two octocorals (Sarcophyton glaucum and Lobophytum sp.) to feed on DOM and compare this ability to that of hexacorals, such as Stylophora pistillata and Turbinaria reniformis. The study measured the net fluxes of DOM under varying DOM concentrations and under heat stress. The results demonstrate that all coral species were net producers of DOM at ambient concentrations, but became net consumers once seawater was supplemented with DOM. Furthermore, our study highlights a relationship between coral physiological responses to heat stress and DOM uptake. Corals that increased (S. pistillata) or maintained (S. glaucum and Lobophytum sp.) their DOM uptake rates at high temperature were the most resilient to heat stress. In contrast, T. reniformis exhibited lower DOM uptake rates at high temperatures, which was associated with significant bleaching. Understanding the ability of corals to feed on DOM may, therefore, provide insight into the resilience of species under ocean warming conditions.

Simultaneous decarbonization and phosphorus removal by Tetrasphaera elongata with glucose as carbon source under aerobic conditions

Previous researches have recognized the vital role of Tetrasphaera elongata in enhanced biological phosphorus removal systems, but the underlying mechanisms remain under-investigated. To address this issue, this study investigated the metabolic characteristics of Tetrasphaera elongata when utilizing glucose as the sole carbon source. Results showed under aerobic conditions, Tetrasphaera elongata exhibited a glucose uptake rate of 136.6 mg/(L·h) and a corresponding phosphorus removal rate of 8.6 mg P/(L·h). Upregulations of genes associated with the glycolytic pathway and oxidative phosphorylation were observed. Noteworthily, the genes encoding the two-component sensor histidine kinase and response regulator transcription factor exhibited a remarkable 28.3 and 27.4-fold increase compared with the group without glucose. Since these genes play a pivotal role in phosphate-specific transport systems, collectively, these findings shed light on a potential mechanism for simultaneous decarbonization and phosphorus removal by Tetrasphaera elongata under aerobic conditions, providing fresh insights into phosphorus removal from wastewaters.

Factors affecting diffusion of polar organic compounds in agarose hydrogel applied to control mass transfer in passive samplers.

Diffusive hydrogel-based passive sampler (HPS) based on diffusive gradients in thin films (DGT) is designed for monitoring polar organic contaminants in the aquatic environment. DGT technique controls the compound's overall uptake rate by adding a hydrogel layer of known thickness, which minimizes the importance of the resistive water boundary layer in the compound uptake process. In this work, we investigated several factors which may influence the diffusion of a range of aquatic contaminants in 1.5% agarose hydrogel. Diffusion in hydrogel was tested using the sheet stacking method. We demonstrated that a thin nylon netting incorporated into the diffusive hydrogel for mechanical strengthening does not significantly affect the diffusion of 11 perfluoroalkyl compounds. Further, we investigated the effect of pH in the range from 3 to 11 on the diffusion of a range of 39 aromatic amines (AAs)-36 aromatic, 2 aliphatic, and azobenzene in hydrogel. AAs were chosen as representatives of compounds with pH-dependent dissociation in water. Analysis of variance showed no significant difference in meandiffusion coefficient log D value at five pH values. The demonstration that the diffusion coefficient D and thus the sampling rate Rs are independent on pH simplifies the interpretation of data from field studies because we can neglect the influence of pH on the Rs. log D values (m2 s-1) of tested AAs ranged from to - 9.77 for 3,3'-dimethylbenzidine to - 9.19 for azobenzene. A negative correlation of log D with molar mass (log M) and molecular volume (log Vm) was observed (R = - 0.57 and - 0.56, respectively). The diffusion coefficient presents a critical parameter for the sampling rate estimation of HPS. Theoretical sampling rates Rs of AAs were calculated for a HPS using the average D values. TheoreticalRs values calculated for AAs at 22°C ranged from 29 mL day-1 for 3,3'-dimethylbenzidine to 106 mL day-1 for 2-aminopyridine. Our calculated values of Rs are in the same range as those already published for a range of low-molecular polar organic contaminants, which supports the possibility of deriving sampler performance parameters in the field from laboratory-derived diffusivity of analytes in hydrogel.

Temporal Variability in Soil Greenhouse Gas Fluxes and Influencing Factors of a Primary Forest on the Eastern Qinghai-Tibetan Plateau

Soil greenhouse gas (GHG) fluxes relate to soil carbon and nitrogen budgets and have a significant impact on climate change. Nevertheless, the temporal variation and magnitude of the fluxes of all three major GHGs (CO2, CH4 and N2O) and their influencing factors have not been elucidated clearly in primary forests on the eastern Qinghai-Tibetan Plateau. Herein, field chamber GHG fluxes from May to November, soil microbial community and enzyme activity were analyzed in a fir-dominated (Abies fargesii var. faxoniana) primary forest. The emission rates of CO2 and N2O ranged between 64.69–243.22 mg CO2 m−2 h−1 and 1.69–5.46 ug N2O m−2 h−1, exhibiting a temporally unimodal pattern with a peak in July. The soil acted as a CH4 sink, and the uptake rate varied between 52.96 and 84.67 μg CH4 m−2 h−1 with the higher uptake rates in June and November. The temporal variation in the CO2 flux was significantly correlated with the geometric mean of enzyme activities, suggesting that the soil CO2 flux was determined by microbial activity rather than soil microbial biomass. The soil N2O flux was positively related to nitrate concentration with marginal significance, probably because N2O was a byproduct of nitrification and denitrification processes. The soil CH4 uptake was closely associated with methanotrophic biomass (18:1ω7c). The results highlight divergent temporal dynamics of GHG fluxes owing to different driving mechanisms and an important CH4 sink in the primary forest soil, helping to evaluate the carbon and nitrogen budgets of primary forests on the eastern Qinghai-Tibetan Plateau.

Pilot study of lung cancer screening for survivors of Hodgkin lymphoma.

Hodgkin lymphoma (HL) treatment increases the risk of lung cancer. Most HL survivors are not eligible for lung cancer screening (LCS) programs developed for the general population, and the utility of these programs has not been tested in HL survivors. We ran a LCS pilot in HL survivors to describe screening uptake, participant characteristics, impact of a decision aid and screen findings. HL survivors treated ≥5 years ago with mustine/procarbazine and/or thoracic radiation, were identified from a follow-up database and invited to participate. Participants underwent a low-dose computed tomography (LDCT) reported using protocols validated for the general population. Two hundred and eighteen individuals were invited, 123 were eligible, 102 were screened (58% response rate): 58% female, median age 52 years, median 22 years since HL treatment; 91.4% were deemed to have made an informed decision; participation was not influenced by age, sex, years since treatment or deprivation. Only three of 35 ever-smokers met criteria for LCS through the program aimed at the general population. Baseline LDCT results were: 90 (88.2%) negative, ten (9.8%) indeterminate, two (2.0%) positive. Two 3-month surveillance scans were positive. Of four positive scans, two patients were diagnosed with small-cell lung cancer; one underwent curative surgery. Coronary artery calcification was detected in 36.3%, and clinically significant incidental findings in 2.9%. LDCT protocols validated in ever-smokers can detect asymptomatic early-stage lung cancers in HL survivors. This finding, together with screening uptake and low false positive rates, supports further research to implement LCS for HL survivors (clinicaltrials gov. Identifier: NCT04986189.).

Full dynamic control of dairy wastewater treatment by aerobic granular sludge using electric conductivity and oxygen uptake rate

Abstract The objective of the current study was to determine the applicability of a sensor-based dynamic control strategy for the treatment of real variable dairy wastewater by aerobic granular sludge (AGS) performing enhanced biological phosphorus removal (EBPR). Two parallel sequencing batch reactors (SBRs) were set up that used only an anaerobic feast/aerobic famine microbial selection strategy to successfully obtain sludge granulation. SBR-STA used a fixed cycle length, while the duration of the reaction steps in SBR-DYN was variable. The control strategy was based solely on (derived) signals from low-cost and common sensors. The profile of the electric conductivity during the anaerobic reaction step was related to the microbial release of phosphate (PO4-P) and the associated uptake of dissolved organic carbon (DOC) by polyphosphate-accumulating organisms (PAOs). Control of the aerobic reaction step was based on the oxygen uptake rate (OUR). This resulted in a dynamic reactor operation with significant efficiency gains, such as 32% shorter cycle times and 42% higher sludge loading rates without impairing the effluent quality. These results extend the existing potential of indirect control strategies to full biological nutrient removal processes, which may be of great assistance to the operators and designers of industrial installations.

The significant contribution of nitrate to a severe haze event in the winter of Guangzhou, China

A severe haze pollution occurred in Guangzhou from January 14 to 16, 2021, during which the mass concentration of PM2.5 ranged from 76 to 243 μg m−3. This level of pollution was rarely observed in recent years considering the improved air quality in Guangzhou. Therefore, it is crucial to comprehensively study the formation mechanisms of this severe haze pollution to prevent its reoccurrence. During the haze period, the concentrations of NO and NO2 sharply increased by 7.4 and 3.8 times, respectively, and total volatile organic compounds (TVOCs) increased 7 times, suggesting enhanced primary emissions from vehicles due to stagnant meteorological conditions. Nitrate concentration (43 ± 20 μg m−3) increased 6.7 times and became the dominant species in PM2.5 during the haze period. Notably, gaseous NH3, HONO and HNO3 also exhibited a sharp increase, suggesting the important role of nitrate chemistry in the evolution of haze pollution. The simulation results from chemical box model revealed that the OH + NO2 reaction was the dominant formation pathway for nitrate production (82 %) during the haze period. The net production rate of ROx radicals (including OH, HO2 and RO2) was 4.4 times higher during the haze period (5.8 ppb h−1) compared to the pre-haze period (1.3 ppb h−1). This was mainly attributed to the enhanced HONO and OVOCs photolysis, which increased from 0.6 ppb h−1 to 3.1 ppb h−1 and 0.4 ppb h−1 to 2.1 ppb h−1, respectively. Furthermore, the sensitivity tests demonstrated the reductions in VOCs and NOx were both beneficial for controlling nitrate production by influencing OH production and N2O5 uptake rate. These findings provide insights into the formation mechanisms of nitrate production during severe haze pollution and suggest that joint mitigation of PM2.5 and O3 can be achieved through the control of VOCs emission.

Renal Cortical Glucose Uptake Is Decreased in Insulin Resistance and Correlates Inversely With Serum Free-fatty Acids.

Studies on human renal metabolism are scanty. Nowadays, functional imaging allows the characterization of renal metabolism in a noninvasive manner. We have recently demonstrated that fluorodeoxyglucose F18 (18F FDG) positron emission tomography can be used to analyze renal glucose uptake (GU) rates, and that the renal cortex is an insulin-sensitive tissue. To confirm that renal GU is decreased in people with obesity and to test whether circulating metabolites are related to renal GU. Eighteen people with obesity and 18 nonobese controls were studied with [18F]FDG positron emission tomography during insulin clamp. Renal scans were obtained ∼60 minutes after [18F]FDG injection. Renal GU was measured using fractional uptake rate and after correcting for residual intratubular [18F]FDG. Circulating metabolites were measured using high-throughput proton nuclear magnetic resonance metabolomics. Cortical GU was higher in healthy nonobese controls compared with people with obesity (4.7 [3.4-5.6] vs 3.1 [2.2-4.3], P = .004, respectively), and it associated positively with the degree of insulin sensitivity (M value) (r = 0.42, P = .01). Moreover, cortical GU was inversely associated with circulating β-OH-butyrate (r = -0.58, P = .009), acetoacetate (r = -0.48, P = .008), citrate (r = -0.44, P = .01), and free fatty acids (r = -0.68, P < .0001), even when accounting for the M value. On the contrary, medullary GU was not associated with any clinical parameters. These data confirm differences in renal cortical GU between people with obesity and healthy nonobese controls. Moreover, the negative correlations between renal cortex GU and free fatty acids, ketone bodies, and citrate are suggestive of substrate competition in the renal cortex.

Accurate low-dose exposure assessment of benzene and monoaromatic compounds by diffusive sampling: sampling and analytical method validation according to ISO 23320 for radiello® samplers packed with activated charcoal.

The research study aimed at providing an accurate low-dose benzene exposure assessment method, by validating diffusive monitoring techniques for benzene personal exposure measurements at workplaces where benzene concentrations are expected in the low ppb range, such as in the present-day chemical, petrochemical, foundry, and pharmaceutical industry. The project was aimed at addressing the need for a robust and fully validated method to perform personal exposure measurements considering that the occupational exposure limit value for benzene is going to be significantly lowered in the next few years. Diffusive sampling offers a reliable alternative to pumped sampling methods, intrinsic safety in potentially explosive atmospheres, lightness, and ease of use. In this study, the radiello® diffusive sampler, with the packed activated charcoal RAD130 adsorbing substrate [suitable for solvent desorption and analysis by high-resolution gas chromatography-flame ionization detection (HRGC-FID)], was used. The experiments have been conducted following the ISO 23320 standard in the range from 0.005 to 0.1 ppm (16 to 320 μg/m3), yielding a full validation of the sampling and analytical method. The sampler performances have fulfilled all requisites of the ISO 23320 standard, in particular: bias due to the selection of a non-ideal sorbent is lower than 10% (no significant back diffusion of benzene due to concentration change in the atmosphere); bias due to storage of samples for up to 2 months is lower than 10%; nominal uptake rate for benzene on RAD130 is 74.65 mL/min; and expanded uncertainty of the sampling and analytical method is 20.6%. The sampling and analytical method is therefore fit-for-purpose for the personal exposure measurements aimed at testing compliance with occupational exposure limit values for benzene. The method is also fit for short-duration exposure monitoring related to specific tasks, and other volatile organic compounds, usually found in the same workplaces, such as aliphatic and aromatic hydrocarbons and some oxygenated compounds, have also been studied. In particular, n-hexane and isopropyl benzene, whose classification is currently under revision, can be efficiently monitored by this technique.

Potential of enriched phototrophic purple bacteria for H2 bioconversion into single cell protein

Single cell protein (SCP) has emerged as an alternative protein source, potentially based on the recovery of carbon and nutrients from waste-derived resources as part of the circular economy. From those resources, gaseous substrates have the advantage of an easy sterilization, allowing the production of pathogen-free SCP. Sterile gaseous substrates allow producing pathogen-free SCP. This study evaluated the use of an enriched phototrophic purple bacteria (PPB) consortium for SCP production using H2 and CO2 as electron and C sources. The influence of pH (6.0–8.5), temperature (15–50 °C) and light intensity (0–50 W·m−2) on the growth kinetics and biomass yields was investigated using batch tests. Optimal conditions were found at pH 7, 25 °C and light intensities over 30 W·m−2. High biomass and protein yields were achieved (~ 1 g CODbiomass·g CODH2consumed−1 and 3.9–4.4 g protein·g H2−1) regardless of the environmental conditions, being amongst the highest values reported from gaseous streams. These high yields were obtained thanks to the use of light as a sole energy source by the PPB consortium, allowing a total utilization of H2 for growth. Hydrogen uptake rates varied considerably, with values up to 61 ± 5 mg COD·d−1 for the overall H2 consumption rates and 2.00 ± 0.14 g COD·g COD−1·d−1 for the maximum specific uptake rates under optimal growth conditions. The latter value was estimated using a mechanistic model able to represent PPB growth on H2. The biomass exhibited high protein contents (>50 % w/w) and adequate amino acid profiles, showing its suitability as SCP for feed. PPB were the dominant bacteria during the experiments (relative abundance over 80 % in most tests), with a stable population dominated by Rhodobacter sp. and Rhodopseudomonas sp. This study demonstrates the potential of enriched PPB cultures for H2 bioconversion into SCP.

Characterizing nitrogen dynamics and their response to sediment dredging in a lowland rural river

It is challenging to quantify nitrogen (N) balance in a lowland rural river covered by macrophytes due to its multiple N sources and complex cycling processes. In order to address the challenge, we developed a N-cycling model (River-N) for lowland rural rivers covered by macrophytes, and coupled it with Nitrogen Dynamic Polder (NDP) and Environmental Fluid Dynamics Code (EFDC) model. A two-year (2020–2021) dataset was used to calibrate and validate the coupled model. The coupled model was used to investigate a lowland rural river’s N imports, exports and its response to sediment dredging, and resulted in an acceptable performance for total N concentrations (TN) (R2 = 0.57). Our investigation conducted in the study river revealed a considerable N retention (difference between imports and exports) ability (955.5 kg yr−1). The river’s N imports were mainly from connected-river import (55.6 %), surrounding-polder export (31.4 %), sediment N release (7.4 %). N exports were mainly from connected-river export (59.0 %), denitrification (31.7 %) and macrophyte uptake (4.4 %). Compared with scenario without dredging, the rates of particulate nitrogen (PN) resuspension and settling increased, and the rates of ammonia nitrogen (NH4+) release, denitrification and macrophyte uptake decreased under the scenario with dredging. During dredging period, the rates of NH4+ release, PN resuspension, PN settling were 2.6, 7.0 and 4.3 times higher than that during pre-dredging period, respectively. The denitrification rate during dredging period was decreased to 43.5 % of that during pre-dredging period. Our investigation results implied that sediment dredging can be a pathway to remove high-N sediment, but did not necessarily decrease TN in river due to external N imports. Considering the critical role of macrophytes in N-cycling, macrophytes should be a critical component requiring our attention in water management practices.

Temporal Evolution and Associated Factors of Adherence to Mammography Screening among Women in Spain: Results from Two National Health Surveys (2017-2020).

Ensuring equity in cancer screening is recommended by the European Commission. Despite the fact that breast cancer screening is a free population-based program in Spain, there remains considerable variation in the adherence to screening rate among population groups. This study was designed to describe the adherence of breast cancer screening in women in Spain, to evaluate the evolution in the period from 2017 to 2020, and to determine the variables that influence choosing to undergo breast cancer screening. A nationwide cross-sectional study with 7220 females aged 50-69 years from the 2017 Spanish National Health Survey and the 2020 European Health Survey for Spain was performed. We investigated mammography uptake rates, with socio-demographic factors, lifestyle habits, and health-related characteristics as independent variables. Multivariable logistic regression was used to identify the associated factors of mammography adherence. Of the women, 78% had undergone mammography in the previous two years, and there was a significant decrease in the uptake rate for breast cancer screening from 2017 (81.23%) to 2020 (74.68%) (p < 0.001). Educational level, marital status, residential location, nationality, smoking status, alcohol consumption, and leisure-time physical activity were all associated factors of mammography uptake.

Towards the Integrative Theory of Alzheimer's Disease: Linking Molecular Mechanisms of Neurotoxicity, Beta-amyloid Biomarkers, and the Diagnosis.

A major gap in amyloid-centric theories of Alzheimer's disease (AD) is that even though amyloid fibrils per se are not toxic in vitro, the diagnosis of AD clearly correlates with the density of beta-amyloid (Aβ) deposits. Based on our proposed amyloid degradation toxicity hypothesis, we developed a mathematical model explaining this discrepancy. It suggests that cytotoxicity depends on the cellular uptake of soluble Aβ rather than on the presence of amyloid aggregates. The dynamics of soluble beta-amyloid in the cerebrospinal fluid (CSF) and the density of Aβ deposits is described using a system of differential equations. In the model, cytotoxic damage is proportional to the cellular uptake of Aβ, while the probability of an AD diagnosis is defined by the Aβ cytotoxicity accumulated over the duration of the disease. After uptake, Aβ is concentrated intralysosomally, promoting the formation of fibrillation seeds inside cells. These seeds cannot be digested and are either accumulated intracellularly or exocytosed. Aβ starts aggregating on the extracellular seeds and, therefore, decreases in concentration in the interstitial fluid. The dependence of both Aβ toxicity and aggregation on the same process-cellular uptake of Aβ-explains the correlation between AD diagnosis and the density of amyloid aggregates in the brain. We tested the model using clinical data obtained from the Alzheimer's Disease Neuroimaging Initiative (ADNI), which included records of beta-amyloid concentration in the cerebrospinal fluid (CSF-Aβ42) and the density of beta-amyloid deposits measured using positron emission tomography (PET). The model predicts the probability of AD diagnosis as a function of CSF-Aβ42 and PET and fits the experimental data at the 95% confidence level. Our study shows that existing clinical data allows for the inference of kinetic parameters describing beta-amyloid turnover and disease progression. Each combination of CSF-Aβ42 and PET values can be used to calculate the individual's cellular uptake rate, the effective disease duration, and the accumulated toxicity. We show that natural limitations on these parameters explain the characteristic distribution of the clinical dataset for these two biomarkers in the population. The resulting mathematical model interprets the positive correlation between the density of Aβ deposits and the probability of an AD diagnosis without assuming any cytotoxicity of the aggregated beta-amyloid. To the best of our knowledge, this model is the first to mechanistically explain the negative correlation between the concentration of Aβ42 in the CSF and the probability of an AD diagnosis. Finally, based on the amyloid degradation toxicity hypothesis and the insights provided by mathematical modeling, we propose new pathophysiology-relevant biomarkers to diagnose and predict AD.

Study on catalytic mechanism of Yb2O3 on RE-Mg based hydrogen storage alloys

Mg90Ce5Y5 + x wt % Yb2O3 (x = 2, 4, 6, 8, 10, 20) samples were prepared by high energy ball milling. The kinetic and thermodynamic properties of the composites were investigated by XRD, TEM, SEM, EDS and PCT. And all samples were tested for hydrogen absorption and desorption. The Mg90Ce5Y5 + 10 wt % Yb2O3 sample displays the fastest hydrogen uptake rate, namely full hydrogenation takes only 125 min at 473 K. And it can fully dehydrogenate in just 75.6 min at 553 K. In addition, the value of Edes is reduced to 95.5 kJ/mol. The improvement of dynamic performance is due to the change of microstructure: Yb2O3/YbH2, YH2 and CeO2 provide plenty of active sites, and abundant defects and grain boundaries lead to the emergence of many high-energy regions and diffusion channels. The ∆H value of Y10 (77.6 kJ/mol H2) is not significantly lower than Mg90Ce5Y5, indicating that the addition of Yb2O3 do not improve the thermodynamic properties.

Abstract 15814: Imaging Local and Systemic Reactive Oxygen Species After Ischemia-reperfusion Injury in Swine With Multimodal 18 F-ROStrace PET/CT and CMR

Introduction Reperfusion injury after myocardial infarction (MI) can cause additional tissue damage and is associated with adverse outcomes, and inflammation of extra-cardiac tissue may occur post-MI. In this study, we used positron emission tomography (PET) radiotracer [18F]ROStrace to image reactive oxygen species (ROS) in myocardium and in extra-cardiac tissues in a swine model of subacute ischemia-reperfusion injury. Methods The mid left anterior descending coronary artery was occluded in three swine for 90 minutes, followed by reperfusion. Baseline and post-MI ROStrace data were acquired 3 days post-MI on the long axial field-of-view PennPET Explorer PET/CT system. A [82]Rb scan was acquired to calculate myocardial blood flow (MBF). Regions of interest (ROIs) were drawn in brain, lungs, bone marrow, spleen, skeletal muscle, myocardium (baseline) and infarcted and non-infarct myocardium (post-MI). ROStrace fractional uptake rate (FUR) was calculated in all ROIs. Cardiac FUR was corrected for MBF. Paired T-tests and Cohen's d effect size (ES) were used to evaluate the effect of MI on ROStrace activity in cardiac and extra-cardiac tissues. Cardiac MRI was done to quantify infarct size. Results In extra-cardiac tissues, MI had a nonsignificant medium effect on ROS in bone marrow (ES = 0.54, p = 0.45) and spleen (ES = 0.60, p=0.41), and a nonsignificant large effect in skeletal muscle (ES = 1.24, p = 0.17). No effect was seen in brain and lungs. In the heart, MI had a significant large effect on ROS in the region of the infarct, compared to baseline (ES = 3.84, p = 0.02) (Fig. 1). Infarct size on late gadolinium enhanced MRI ranged from 16.73 to 33.62% of the myocardium. Conclusion For the first time, systemic and local effects on ROS after MI were directly imaged using whole-body [18F]ROStrace PET. We found that ROS are increased in the infarcted myocardium in the subacute phase, and MI leads to moderate-to-large effects in ROS levels in hematopoietic tissues and skeletal muscle.

240 Prolonged Maternofetal Inflammation in the Pregnant Ewe at Mid-Gestation Increases Subsequent Fetal Inflammatory Tone and Disrupts Skeletal Muscle Growth and Glucose Metabolism Near Term

Abstract Chronic maternofetal inflammation in late gestation (i.e., peak fetal growth) causes fetal intrauterine growth restriction (IUGR) in sheep, which was associated with deficits in growth, body composition, and metabolic function before and after birth. However, the impact of sustained maternofetal inflammation during mid-gestation (i.e., peak placental growth and development) has not been explored. Therefore, our objective was to determine the effects of sustained maternofetal inflammation during this critical window on subsequent fetal inflammatory tone, metabolism, and myoblast (i.e., muscle stem cell) function. Pregnant ewes were injected every 3rd day from the 50th to 65th d of gestational age (dGA; term = 150 dGA) with saline (control; n = 12) or bacterial lipopolysaccharide endotoxin to induce maternofetal inflammation and IUGR (MI-IUGR; n = 12). Fetuses were surgically catheterized on dGA 118 to collect blood samples, and a hyperinsulinemic-euglycemic clamp (HEC) was performed on dGA 123. Fetuses were necropsied on dGA 125 to collect semitendinosus muscle samples. Fetal plasma TNFα concentrations tended to be greater (P = 0.07) for MI-IUGR fetuses (440 ± 45 pg/m l) than for controls (348 ± 24 pg/mL). Fetal blood O2 partial pressures were 12% less (P &amp;lt; 0.05) and maternofetal O2 gradients tended to be 11% greater (P = 0.08) for MI-IUGR fetuses than for controls. Hindlimb-specific glucose uptake rates did not differ between fetal groups, but hindlimb-specific glucose oxidation rates were reduced (P &amp;lt; 0.05) by 15% under basal conditions and by 27% under hyperinsulinemic conditions for MI-IUGR fetuses compared with controls. Semitendinosus glycogen content and β2 adrenoceptor content did not differ between fetal groups, but semitendinosus content of the TNFα receptor, TNFR1, was 41% greater (P &amp;lt; 0.05) for MI-IUGR fetuses than for controls. Immunohistochemistry revealed 18% fewer (P &amp;lt; 0.05) proliferating myoblasts (pax7+/Ki67+) and 38% fewer (P &amp;lt; 0.05) differentiated myoblasts (myogenin+) in semitendinosus from MI-IUGR fetuses compared with controls, which coincided with 13% smaller (P &amp;lt; 0.05) muscle fibers. From these findings, we conclude that sustained maternofetal inflammation during peak placental development at mid-gestation resulted in enhanced fetal inflammatory tone near term, which in turn impaired myoblast function, muscle fiber hypertrophy, and muscle glucose metabolism.