240106 research outputs found
Sort by
Artificial Intelligence-Based Modeling and Control Strategy for Dual Active Bridge Converter with Triple Phase Shift Modulation
No full textDual active bridge (DAB) converter, known for its exceptional performance in bidirectional power transmission, has emerged as a crucial power conversion unit in energy storage systems and dc power systems. To improve the efficiency under wide voltage variations, the triple phase shift (TPS) modulation is typically used. However, the existing analytical models and control strategies of DAB with TPS modulation mostly depend on complex theoretical derivations, neglecting nonideal factors or exhibit heavy computational burdens. To tackle this issue, an artificial intelligence (AI)-based modeling and control strategy is proposed. First, a numerical simulation model incorporating the dynamic behavior of DAB circuit during dead time and parasitic parameters is developed to efficiently generate the training dataset. Building upon this, a general AI model of TPS modulation is precisely formulated, which is concise and applicable to various circuit parameters and all switching modes. Subsequently, a multilayer heuristic algorithm is employed to effectively derive optimal steady-state strategies. In addition, a concise artificial neural network is constructed to fit the offline control law and generate the optimal strategies online. Furthermore, an adaptive neural network sliding mode controller is designed. It integrates the general AI model with nonlinear sliding mode control theory, while a recurrent neural network compensates for errors adaptively, exhibiting excellent robustness and transient performance. Finally, comparative experiments demonstrate the effectiveness and superiority of the proposed approach.</p
Efficient co-removal of aqueous Cr(VI) and ciprofloxacin by alkali lignin-derived carbon supported nanoscale zero-valent iron via adsorption and redox synergistic mechanisms
No full textDeveloping an efficient co-removal strategy is crucial for the treatment of combined contaminants with heavy metals and antibiotics due to their great threat to sustainable advancement and ecological preservation. Herein, the efficient co-removal of aqueous hexavalent chromium (Cr(VI)) and ciprofloxacin (CIP) is achieved via a newly developed composite of nanoscale zero-valent iron particles embedded into alkali lignin-derived carbon (nZVI/ALC) without external assistance (such as light, advanced oxidants). nZVl/ALC demonstrates superior co-removal efficiencies of Cr(VI) (99.9 %) and CIP (89.9 %) with high removal kinetic rate constants of 1.595 and 0.779 min−1, respectively. The underlying mechanisms involving the co-removal of Cr(VI) and CIP verify that Cr(VI) ions are adsorbed onto the skeleton of nZVI/ALC originating from the electrostatic interaction, and CIP molecules adsorbed on nZVl/ALC act as a bridge, complexing with the Cr(VI) ions to promote Cr(VI) removal. Meanwhile, the CIP adsorption by nZVI/ALC involves hydrogen bonding, π-π interaction, and complexation. The coexisting Cr(VI) ions are transformed into Cr(III) components with abundant electron transfer, leading to the generation of more •O2– radicals, thus the self-generating reactive oxygen species (•OH, •O2– and 1O2) in ambient-air condition promote CIP degradation in the binary system. The CIP molecules’ degradation pathways mainly include piperazine ring cracking, piperazine epoxidation, quinolone ring opening and defluorination according to the analysis of HPLC-MS and FuKui function, along with the gradual reduction in toxicity throughout the degradation process of CIP molecules. This study offers a new insight on the co-removal of Cr(VI) and CIP, which would provide promising guidance for the remediation of compound wastewater with heavy metals and antibiotics
Diversitet og lighedsarbejde i organisationer:Affekt og handling i en dekolonial univers
No full textShaping Power Dynamics and Social Imaginaries in Volunteer Efforts with Ukrainian Refugees
No full textIntensity and enjoyment of play-based HIIT in children and adolescents with obesity
No full textHigh-intensity interval training (HIIT) has been suggested as an effective treatment approach of childhood obesity. The objective of the present study was to examine intensity, enjoyment, and perceived exertion of a 4x4-minute play-based HIIT program for children and adolescents with obesity. 83 participants (42.2% girls, 12.3±1.5 years, 57.8% boys, 12.0±1.6 years) completed a 12-week intervention comprising three weekly sessions. After nine sessions (weeks 2, 6, and 11), participants rated perceived exertion (RPE) with a Borg scale and enjoyment of activities using the Physical Activity Enjoyment Scale (PACES). Heart rate (HR) was recorded to assess time spent in high- and moderate-intensity. Participants spent more time in high-intensity during strength-based(P=0.004) and running-based(P=0.007) activities compared to ball games, and more time was spent in moderate-intensity during ball games compared to strength-based(P=0.033) and running-based(P=0.028) activities. Overall, boys spent more time in moderate-intensity than girls(P=0.007). Participants rated RPE lower for ball games than for strength-based(P<0.001) and running-based(P<0.001) activities. Boys rated running-based activities more enjoyable than girls(P=0.021). Exercise intensity and RPE vary by activity in HIIT for children and adolescents with obesity. Ball games led to less high-intensity time and were seen as less exhausting. No differences in RPE or enjoyment were found over time.</p
Bipolar disorder in people with HIV: A nationwide, population-based matched case-control and matched cohort study
No full textObjectives: To assess whether bipolar disorders are associated with the risk of HIV infection and whether the risk of bipolar disorders is increased among people with HIV (PWH) and their siblings.Design: Nationwide, population-based, combined matched nested case-control and cohort study of PWH of Danish origin (1995–2021), a comparison cohort from the background population, matched on date of birth and sex, and sibling cohorts.Methods: Conditional logistic regression and Cox regression was used to calculate adjusted odds ratios (aORs) for HIV infection and hazard ratios among PWH for bipolar disorder and receipt of lithium.Results: We included 5322 PWH and 53 220 comparison cohort members. In the case–control study, bipolar disorder was associated with an increased risk of HIV infection [aOR: 1.9, 95% confidence interval (CI): 1.2–3.0], especially when injection drug use was the route of infection (aOR: 7.6, 95% CI: 2.0–28.9). In the cohort study, we observed an increased risk of bipolar disorders among PWH, especially in the first 2 years of observation (hazard ratio: 4.2, 95% CI: 2.4–7.4), whereas the risk of receipt of lithium was lower and the CI crossed 1. The 20-year risk of bipolar disorders for PWH was approximately 1%. Siblings of PWH also had an increased risk of bipolar disorder but not to the same degree as PWH and not of receipt of lithium.Conclusion: Bipolar disorders are associated with the risk of HIV infection, and PWH have increased risk of bipolar disorder and receipt of lithium beyond what familial factors could explain
A nociceptor excitability test for identifying alterations of the Nav1.7 channels in humans
No full textSodium channel variants are associated with small fiber neuropathy. While in vitro recordings allow detailed assessment of sodium channel function, their contribution to peripheral small nerve fiber excitability remains unstudied. The perception threshold tracking (PTT) method allows indirect assessment of small fiber function by transcutaneous electrical stimulation and psychophysics. Here, we developed a Sodium channel Excitability Nociceptor Test that allows for the identification of alterations in selected subtypes of sodium channels in small fibers of awake humans. We hypothesize that due to the unique dynamics of sodium channels, it is possible to derive a nerve excitability test to uniquely identify alterations in the Nav1.7 channel. Using a multicompartmental nerve fiber model, a set of 5 electrical pulse shapes was developed. These pulse shapes consist of rectangular and ramp test pulses preceded by either a hyperpolarizing or depolarizing prepulse. To validate the predictive power of our in silico simulations, we used an automated whole-cell patch clamp on Nav1.7 expressed in HEK293T cells and a PTT experiment in healthy participants. The computational model predicted that an alteration of Nav1.7 can be classified with an accuracy of 92% (n = 30) when the standard deviation of the perception threshold is 11%, which was measured by the PTT experiment. The peak Nav1.7 current elicited in vitro corresponded well with the prediction of the in silico model. The study thus provides an excitability test to predict the involvement of Nav1.7, and potentially also Nav1.8 and Nav1.9, in the generation of neuropathic pain in small fiber neuropathy.</p
Protein distribution in SBA-15:Insights from thermal decomposition and advanced imaging
No full textOrdered Mesoporous Silica (OMS) materials, particularly SBA-15, are widely used in drug delivery due to their structural stability and high porosity. However, the role of macroporosity (pores >50 nm) in influencing protein adsorption and spatial distribution remains poorly understood. In this study, three SBA-15 variants were produced by changing the synthesis temperature and stirring speed, and combined evolved gas analysis (EGA), Raman imaging, and X-ray micro-computed tomography (micro-CT) were used to investigate the adsorption and distribution of lysozyme, a model protein, in the samples. While thermal analysis showed comparable overall protein uptake across all variants, Raman imaging and micro-CT demonstrated that SBA-15 with the larger macropore distribution exhibited a less uniform lysozyme distribution. These observations suggest that macroporosity affects protein localization within SBA-15, which is critical for optimizing antigen delivery and release. Our results advance understanding of how OMS morphology impacts biomolecule encapsulation, offering insights valuable for the design of advanced drug delivery systems and oral vaccines.</p
Effects of culture conditions on cell morphology and differentiation responses to PMA in THP-1 cells
Get PDFThe THP-1 monocyte cell line can be differentiated into macrophage-like cells upon stimulation with phorbol 12-myristate 13-acetate (PMA) and therefore widely used in inflammatory research. However, there is a lack of evidence-based protocols for cell culture and differentiation. In this study, we highlight how culture conditions influence THP-1 cells and their response to PMA stimulation. After thawing, THP-1 cells were cultured for up to 4 weeks and monitored by phase-contrast microscopy. Stressed cells (>1 × 10 6 cells/mL for 72 h without medium replenishment) were assessed for CD80 and MHC-II expression and the subset distribution by flow cytometry. For PMA stimulation (10 μg/mL), standard cells under normal nutrient conditions (5 × 10 5 cells/mL), low (2 × 10 5 cells/mL), and high (1 × 10 6 cells/mL) cell densities, along with stressed cells at 1 × 10 6 cells/mL density, were seeded and observed at 24 and 48 h. Cells formed aggregates containing more than 10 cells during the first week in suspension but gradually transitioned to single cells with continuous culture. Metabolically stressed cells developed protrusions, showed increased adherence, and expressed higher levels of MHC-II compared to standard cells ( p = 0.02). These cells also displayed signs of partial differentiation, with fewer MHC-II −CD80 − cells ( p < 0.001) and more MHC-II +CD80 − cells ( p < 0.001) than non-stressed cells. Optimal and uniform differentiation was observed after 3–4 weeks of recovery, at seeding densities below 1 × 10 6 cells/mL, and under non-stressed conditions. These findings show that THP-1 culture conditions, including recovery time post-thawing, stress status and seeding density, have a major impact on their responsiveness to PMA.</p