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Dissolved air flotation of Chlorella sp. using chitosan: influence of algal organic matter and growth phase on coagulant dose
No full textThis study investigates the efficient separation of Chlorella sp. microalgae using dissolved air flotation with chitosan as a coagulant. Improving the harvesting process, which significantly contributes to total costs and carbon footprint, could lead to competitive microalgae products and commodities. The exponential phase required 0.20 mg⋅mg 1 1 chitosan, which is almost two times more than the chitosan dose of 0.12 mg⋅mg required for the stationary phase of growth, although the algal biomass concentration had increased from 0.26 ± 0.06 to 0.53 ± 0.01 mg⋅L and the concentration of algal organic matter from 8 to 32 mg C⋅L 1 1 in dissolved organic carbon, respectively. It is also shown, via Microscope Force Spectroscopy, that the cell measured directly from the culture had bound algal organic matter to their surface at pH 8.5, increasing their softness (Young’s Modulus = 8.1 ± 10 kPa), roughness (4.2 ± 2.4 nm) and interaction with bubbles (2.5 ± 2.1 nN, adhesion 64.4 %), compared to the washed cells in PBS buffer at pH 7.4 (1474 ± 1053 kPa; 1.3 ± 0.4 nm; 0.8 ± 0.5 nN, adhesion 9.1 %, respectively). Polysaccharides, mainly containing arabinose (29.2 ± 6.9 % and 33.0 ± 1.7 % dw polysaccharide) and galactose (34.2 ± 8.1 % and 17.43 ± 1.3 % dw), while acidic residues of the polysaccharides (6.7 ± 2.1 % and 13.1 ± 5.8 % Area) were also present along with protein (9.1 ± 2.2 % and 0.9 ± 0.2 % dw AOM) in exponential and stationary growth phase, respectively. Nevertheless, the relationship between AOM composition and its underlying structure and functionality is not yet fully understood.This work was supported by Research Foundation Flanders (FWO junior fundamental research project - G050220N, FWO scientific exchange program Tournesol - VS01322N).
Acknowledgements We would like to acknowledge the technicians’ support of Guy Reggers, Jenny Put, Elsy Thijssen, Martine Vanhamel, Bernard Noppen for TGA analyses, Ion Chromatography, HPAEC-PAD, FTIR, and PY-GC/ MS
Elucidating Carrier Dynamics and Interface Engineering in Sb2S3: Toward Efficient Photoanode for Water Oxidation
No full textConjugation of low-cost and high-performance semiconductors is essential in solar-driven photoelectrochemical (PEC) energy conversion. Sb2S3 is a wide-bandgap (approximate to 1.7 eV) semiconductor with the potential to deliver a maximum photocurrent density of 24.5 mA cm-2, making it highly attractive for PEC water splitting applications. However, bulk Sb2S3 exhibits intrinsic recombination issues and low electron-hole separation, posing a limit to photocurrent generation. This study clarifies the carrier dynamics by ultrafast spectroscopy measurements and proposes the design of a heterojunction between Sb2S3 and SnO2, with suitable band-edge energy offset. The SnO2/Sb2S3 heterojunction enhances the charge separation efficiency, resulting in improvement of the photocurrent. The SnO2/Sb2S3 photoanode, fabricated entirely by vapor deposition processes, demonstrates photoelectrochemical water oxidation with a photocurrent density up to approximate to 3 mA cm-2 at 1.38 V versus RHE.I.D.T. and A.S. are first authors and equally contributed to this work. S.S. acknowledges European Union’s Horizon Europe program for funding under the Marie Skłodowska-Curie Grant Agreement No. 101067667. S.S. and B.V. acknowledge Catalisti VLAIO (Vlaanderen Agentschap Innoveren & Ondernemen) through the Moonshot SYN-CAT project (HBC.2020.2614), KESPER (M-ERA.NET), and Interreg FOTON project. S.S., B.V., and V.K.S. acknowledge support from Belgian federal government through the Energy Transition Fund for T-REX project. A.S. acknowledges CeSAR (Centro Servizi Ateneo per la Ricerca) at University of Cagliari and Dr. Marco Marceddu for technical
assistance. A.S. was supported by PON R&I 2014-2020 CCI2014IT16M2OP005 Azione IV.4. Green—CUP F35F21002390008. I.D.T. thanks FWO for the funding through the Fundamental Research Ph.D. Fellowship (11PNM24N) and Travel Grant for a short stay abroad (V434524N)
Value of information of static and modal data for a concrete bridge exposed to reinforcement corrosion
No full textMeasurements performed on ageing bridges can provide information on the remaining capacity of these structures. Nevertheless, these measurements come at a cost, whereas the budgets for maintenance are limited. Based on pre-posterior analyses, the Value of Information (VoI) of these measurements can be determined on beforehand and the most optimal measuring strategy can be chosen. However, applying these VoI analyses to real- world structures, considering the time-dependent and spatial character of degradation, can be challenging. In this work, a case study is considered where the VoI analysis is applied to a reinforced concrete girder bridge subjected to corrosion, considering two situations: one with corrosion due to carbonation and one with corrosion due to chlorides. The influence of different assumptions in the VoI analysis is investigated
Penile venous malformation in a child: case report and literature review
No full textcitation ID: qdaf077.241 Objectives: Venous malformations (VMs) are the most common vascular anomalies. Given the potential for aesthetic and psychological impacts, management can be challenging. Here, we present the case of a rare VM of the glans, and give an overview of the published literature on the subject. Methods: For the literature review, a PubMed search was conducted using the keywords "venous malformation", "penis", "glans", "child", "sirolimus". Results: We report the case of a 17-year-old patient presenting with a mass on the glans (Image 1), present since the age of 11. There was no history of trauma or urinary dysfunction. Medical history includes circumcision in childhood and excision of a a capillary hemangioma at age 14. Clinical examination revealed a 11 mm diameter, bluish, compressible mass on the glans. The appearance was typical of a venous malformation, and a doppler ultrasound confirmed that the malformation was confined to the skin. No CT scan or IRM were requested due to the small size and location of the lesion. Surgical excision was suggested to the patient and his parents, who preferred to defer treatment. The primary goal of treatment is to reduce pain, functional consequences, bleeding, and thromboembolic complications. The size and extent of the lesion define the choice of treatment. Curative treatments include surgery, sclerotherapy, cryother-apy, laser ablation or the use of the mTOR inhibitor sirolimus. In the most complex cases, a multimodal approach can achieve optimal results. Conclusions: Concerning diagnosis, a thorough clinical examination and anamnesis are often enough for the practitioner to identify a venous malformation. Imaging by ultrasound or MRI is often indicated to assess the extent of the lesions. Management always requires interdisciplinary discussion. The location and extent of the VM on the penis are key factors in deciding the best management option. For the management of VMs, each technique has its own indications, advantages, and disadvantages, and can be used multimodally to achieve optimal long-term results. Targeted therapies such as sirolimus appear promising, but further studies are needed to prove their efficacy compared with conventional treatments such as surgery or sclerotherapy
A Review on Disability-Inclusive Public Transportation: Current Barriers and Prospects
No full textPeople with disabilities face significant barriers in using public transport, limiting their access to healthcare, employment, education, and daily life activities. A comprehensive review of existing research critically identifies these barriers, analyzes efficient interventions, and uses modern technology to create inclusive public transport systems that empower people with disabilities and foster a more equitable society. The current review systematically identifies the key barriers and prospects of disability-inclusive public transportation. It also highlights the policy shortcomings, accessibility gaps, and current technological advancements to foster inclusivity and improve mobility needs for disabled individuals. Searching scientific databases Scopus and Web of Science yielded 1100 articles; 35 met the inclusion criteria. The selected studies were conducted in various countries, emphasizing the topic's geographical importance. Several studies in the last five years indicated the topic's growing interest and potential impact. The present study categorized the key barriers into five types: inaccessible infrastructure, information and communication, attitudinal, economic, and safety and security. Case studies from diverse geographical and social settings correlated the barriers with the satisfaction levels of people with disabilities. The case studies highlighted the critical problems disabled people face that should be considered while designing successful transportation systems and travel chains. The study also illustrates the key features of a successful transportation system for disabled people based on best practices adopted worldwide. The prospects of using advanced technology, such as machine learning and modern imagery techniques, are also discussed.Deanship of Graduate Studies and Scientific Research, Qassim Universit
“Postural control and emotions – are center of pressure parameters affected by emotional imagery in healthy individuals?”
No full textBackground and aim
The relationship between postural control and emotions is intricately intertwined in our behaviors (e.g., stiffening strategies when exposed to threat). However, it is very complex and largely unexplored. A potential way to elucidate the effects of emotions on postural control is through script-driven emotional imagery, which is known to be a valid and reliable way to induce emotions. As it has not yet been used in the research field of postural control we aimed to examine the effect of script-driven emotional imagery on center of pressure (CoP) in healthy individuals.
Methods
Participants listened to four emotional imagery scripts by means of stories exposed through headphones. The first was a neutral script, the other three were designed to induce emotions of acceptance, hostile-resistance, and relaxation. The subjects were instructed to imagine the stories as vividly as possible while standing upright on a foam pad with their eyes closed and arms hanging next to their body in a darkened room. Each emotional imagery script consisted of a baseline, imagery, and recovery phase. After each script, the subjects rated valence (pleasant to unpleasant), arousal (excited to calm), and dominance (dominated to in control) with the Self-Assessment Manikin (SAM) to check whether emotion induction was successful. Postural control was quantified by various CoP parameters: mean sway and standard deviation of sway, total sway, and sway velocity in both anteroposterior direction (AP) and mediolateral direction (ML), as well as the 95% confidence interval of the total sway area. Effects of the emotional imagery scripts on CoP and whether or not the emotions were successfully induced were analyzed using a mixed model. For CoP, the mixed model was based on difference scores between the baseline and imagery phases of each script.
Results
Based on the SAM, the scripts successfully induced the intended emotions, as participants felt less pleasant (p< 0.0001), more aroused (p< 0.0001), and less in control (p< 0.0001) during the hostile-resistance script compared to the acceptance and relaxation scripts and during the acceptance script compared to the relaxation script. However, with an exception for mean CoP sway AP, which was smaller during the relaxation script in comparison to the acceptance script (p= 0.04), none of the scripts revealed any effect on CoP variables.
Conclusion
Although script-driven emotional imagery was successfully induced in healthy individuals, the scripts minimally affected postural control. These findings may suggest that healthy individuals adopt flexible compensation strategies (both postural and emotional) to successfully adjust for induced perturbations
Van klacht naar kans? Hoe hotels omgaan met taalklachten
No full textStel je boekt via Booking.com een hotel in Amsterdam voor een weekendje weg. Bij de check-in word je in het Engels begroet. En zelfs als je duidelijk maakt dat je Nederlands spreekt, zegt de baliemedewerker: “In English, please”. In online reviews zien we dat Nederlandse toeristen klagen over het Engelse taalgebruik in hotels in eigen land. En hotels pareren dit niet altijd effectief in hun online reacties, laat onderzoek van Mariet Raedts en Irene Roozen zien
Smart Transfection: In-flow electroporation with self-learning capabilities using integrated impedance cytometry modalities
No full textIntracellular delivery of exogenous cargo is an essential step in many cell engineering applications. The limitations and stringent safety
requirements of viral methods have researchers looking at physical methods. However, the optimization remains to be a time-consuming
procedure, making the development a long and costly process.
Here we combine in-flow electroporation and real-time data from impedance cytometry modalities together with machine learning techniques
to enable a dynamic optimization process. We envision this device to not only reduce optimization times, but also enable real time in-situ
monitoring of the in-flow electroporation process on an individual cell level
Exercise training in heart failure with preserved ejection fraction patients: the importance of resistance training
No full textChronic heart failure with preserved ejection fraction (HFpEF) is the dominant form of HF, with an increasing prevalence and until recently very limited management options (e.g. diuretics, gliflozins, and incretin therapies). 1 Exercise intolerance (EI) presents one of the most common symptoms of HFpEF and is associated with a decreased quality of life (QoL) and increased risk of HF-related hospitalization and mortality. 1 The pathophysiology of EI is however complex and consists of pulmonary, skeletal muscle, vascular, and cardiac abnormalities that can substantially impact cardiac output, oxygen transport, and utilization to the exercising muscles, thereby leading to a substantial reduction in peak oxygen consumption (peak VO 2) and muscle strength. 1 This multiorgan dysfunction cannot be remediated by cardiovascular pharmacotherapy or cardiac implantable electronic devices only; therefore , optimal lifestyle management strategies are needed as well to improve the EI-related symptoms and outcomes. 1 Exercise training (ET), as part of cardiac rehabilitation (CR), may alleviate the symptoms of HFpEF and has been associated with superior improvements in (sub)maximal aerobic capacity, muscle strength, and QoL and decreases the risk of all-cause and HF hospitalization in HF patients. 2 Current evidence on ET in CR was established on mostly patients with HF with reduced EF (HFrEF), 2 while the evidence in HFpEF patients is growing. Recently completed studies have demonstrated superior effects of moderate-intensity continuous or high-intensity interval aerobic training (AT) alone or combined with resistance training (RT) on peak VO 2 over standard care alone. 3,4 While these studies have provided important information for improving exercise-based CR in HFpEF, there may be (emerging) ET approaches that should be adopted for this patient group. For example, recent evidence suggests that moderate-to-high load RT [MHL-RT; 55-80% of one repetition maximum (1-RM)] is safe and can provide greater benefits on peak VO 2 and maximal muscle strength, compared with AT alone in coronary artery disease (CAD) patients. 5 Therefore, it remains interesting to assess whether the implementation of MHL-RT may provide additional benefits on exercise performance in HFpEF patients. In this issue of the European Journal of Preventive Cardiology, Palau et al. 6 sought to determine the effects of novel ET approaches on improving symptoms of EI in HFpEF patients, all with chronotropic incompetence (chronotropic index <0.62 or <0.80 for patients previous on or without β-blocker therapy, respectively). The novelty of this paper is that the authors for the first time targeted the chronotropic incompetence with supervised ET intervention. In the study, the authors rando-mized 80 HFpEF patients to exercise counselling alone (counselling on regular unsupervised aerobic and resistance exercise), high-intensity AT alone (twice weekly, intervals of 1 min of high-intensity aerobic exercise separated by 2 min of active recovery), combination of inspiratory muscle training (20 repetitions at 40-60% of maximal inspiratory pressure performed twice daily), AT and low-load RT (LL-RT) (3 sets of 20 repetitions at 30-50% of 1-RM performed twice weekly), or MHL-RT (3 sets of 12 repetitions at 55-75% of 1-RM performed twice weekly). The study assessed changes in peak VO 2 (mL/kg/min and %), QoL, chronotropic response, and safety of and adherence to exercise intervention. After 12 weeks of intervention, all three supervised ET groups improved peak VO 2 max, health-related QoL, and chronotropic response to a greater extent when compared with exercise counselling alone. The combination of home-based inspiratory muscle training with supervised AT and MHL-RT was superior to AT alone on the improvement in peak VO 2 , while all supervised ET interventions induced similar improvements in QoL and chronotropic response, with 38% of the patients in the ET groups restoring their chronotropic response. In addition, all ET interventions were safe, well tolerated (all patients completed more than 83% of prescribed ET sessions) with no adverse cardiovascular events. This study elegantly presents several novel insights into the benefits of concurrent ET methods (e.g. combination of AT and RT) to tackle the highly prevalent EI symptoms of HFpEF patients. First, the study clearly shows that supervised ET should be offered for HFpEF patients instead of exercise counselling alone that showed no clinical benefits. Second, this study demonstrates the importance of combining A