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Towards an indicator-based morphological informality model for Sub-Saharan Africa using open building footprint and road data (Version 1)
Get PDFThis study addresses the challenge of accurately mapping informal settlements, which are home to over a billion people globally. Current maps often simplify these areas into binary categories, ignoring the nuanced dimensions of deprivation. The research focuses on ”unplanned urbanization,” a key domain in informal settlement mapping, and proposes a method to classify morphological informality into three deprivation levels (low, medium, and high) based on two subdomains: small, dense structures (SDS) and irregular settlement layouts (ISL). The methodology involves analyzing building footprints and road network data using urban morphometrics, clustering these metrics into subdomains with k-means, and validating results with community-sourced reference data. Tested in Nairobi, Kenya, and Lagos, Nigeria, the model achieves good performance (F1 > 65 for indicator maps) but faces challenges in the medium informality class, particularly in Nairobi, where community feedback diverges significantly. Despite an overall accuracy of 48 % for Nairobi and 60 % for Lagos, the model offers a framework for continuous improvement. This work highlights the value of integrating local perspectives into mapping efforts and provides a scalable, transferable approach for identifying levels of morphological informality
Reduction of radiofrequency induced implant heating via flexible metasurface shielding at 7 T
Get PDFPassive implanted devices are commonly contraindicated at ultra-high field MRI due to the risk of radiofrequency heating. Mitigation of this risk has come in many forms, such as modifying implant materials or creating novel radiofrequency coils. These methods require substantial involvement from manufacturers and may not benefit patients with existing implants. In this study, a tailored metasurface design is demonstrated to improve implant safety at 7 T by shielding the local B1+ field. A prototype metasurface was designed and implemented with a unit cell size of 15 mm using discrete capacitors of 30 pF values. Phantom and human body model simulations were used to validate differences in the SAR distribution with and without the metasurface. Fiber optic temperature probes were used to measure temperature increase across two representative orthopedic screws placed inside a tissue mimicking phantom during a high-SAR sequence. Phantom and in-vivo imaging were performed to assess the metasurface effect on image quality. With the metasurface, an average maximum temperature decrease of 0.50 °C or 34.9 % near the implant was observed. RF field simulations yielded similar decreases in SAR for the phantom (40.7 %) and substantial decreases for the in-vivo leg model (97 %). Phantom image SNR showed a global 8.5 % decrease with the metasurface while in-vivo images showed a 4.8 % decrease in SNR, with the region in its immediate vicinity experiencing substantial signal drop. These results demonstrate the feasibility of a metasurface designed to substantially reduce local RF induced heating with only minor degradation of image quality. Future work will focus on refinement of the metasurface design and further in-vivo testing.</p
Electrochemical CO2 reduction to alcohols using flexible and rigid MOF electrocatalysts
No full textMetal–organic frameworks (MOFs) are a versatile class of materials with significant potential for electrochemical CO2 reduction to multicarbon products. Most MOFs for electrocatalysis rely on benzene-ring-containing linkers, but their limited electrocatalytic activity hinders progress. Flexible MOFs, constructed from aliphatic-chain-containing linkers, offer an alternative due to their ability to respond to external stimuli such as electricity. Despite their potential, few studies have explored flexible MOFs for electrochemical CO2 reduction to value-added liquid products. This work synthesized two MOFs using metal nuclei (Mg and Zn) and distinct organic linkers: oxalic acid and 2,5-dihydroxyterephthalic acid (H4DOBDC, MOF-74). Electrochemical analysis revealed that the flexible MOF derived from oxalic acid exhibited superior charge transport properties, as confirmed by electrochemical impedance spectroscopy (EIS). Structural and chemical analyses, such as TEM, XRD, XPS, and acidity tests with pyridine, were performed using the synthesized MOFs. In situ ATR-FTIR during electrolysis and post-electrolysis using 1H NMR revealed the production of diverse carbon products, including ethanol, isopropanol, and methanol. The oxalic acid MOF demonstrated superior selectivity over well-known MOF-74 at −0.19 V vs. RHE. This study highlights the advantages of flexible MOFs over conventional benzene-based frameworks and paves the way for their application in CO2 electroreduction to liquid products
Immunogenic cell death as interplay between physical anticancer modalities and immunotherapy
No full textCurrent cancer treatment strategies in practice nowadays often face limitations in effectiveness due to factors such as resistance, recurrence, or suboptimal outcomes. Traditional approaches like chemotherapy often come with severe systemic side effects due to their non-specific action, prompting the development of more targeted therapies. Among these, physical ablation techniques such as radiotherapy (RT) and focused ultrasound (FUS) have gained attention for their ability to precisely target malignant tissues, reduce physical and mental stress for the patients, and minimize recovery time. These therapies also aim to stimulate the immune system through a process referred to as immunogenic cell death (ICD), enhancing the body's ability to fight cancer, explaining abscopal effects. RT has been the most established of the abovementioned techniques for decades, and will not be included in the review. While initially focused on complete tumor ablation, these techniques are now shifting towards milder, more controlled applications that induce ICD without extensive tissue damage. This review explores how physical ablation therapies can harness ICD to boost anticancer immunity, emphasizing their potential to complement immunotherapies and improve outcomes for cancer patients.</p
Develop to last:The impact of operating systems on smartphone longevity
Get PDFConsumers in Europe replace around 136 million smartphones every year. These devices contain numerous critical raw materials essential to the transition to renewable energy. Moreover, mining these materials often involves unsafe and unethical working conditions, and their scarcity increases Europe's dependency on other regions.To preserve critical raw materials within the region, Europe is striving to transition to a circular economy. So far, much of the focus in this transition has been on recycling; however, both return and recycling rates of smartphones remain low. An alternative, and much more effective, strategy is to extend product lifespans. While progress has been made in advancing repairability, the promising opportunity to prolong the lifespan of smartphones by replacing its operating system remains overlooked.It’s a familiar situation many of us have experienced: although your phone still functions perfectly well, certain apps stop working because the operating system (OS) no longer supports the apps. As a result, you're forced to buy a new phone—even though the hardware of your phone still works fine and could last for years to come.This whitepaper explores what the impact is of the operating system (OS) of a smartphone on its lifespan, costs and environmental impact.The study indicates that the OS of Android smartphones can be replaced by another operating system which:• almost doubles the lifespan of a smartphone (from nearly 5 years to over 9 years)• reduces the costs for the user with 66% (from € 9,09 to € 3,10 per month)• has the potential to decrease the environmental impact of smartphones in Europe with 3,677 million ton CO2 emissions every year and• has the potential to reduce the consumption of valuable materials with 7263 ton every year.Promising next steps to these findings are to technically test the hardware with the alternative OS over a longer lifespan with different usage patterns. Furthermore, a similar problem seems to be emerging for televisions. Developing an alternative OS for televisions could bring many benefits to users and the natural environment
Pelvic osteotomies for correction of sagittal imbalance of the spine:An in-silico study comparing four different osteotomies
No full textThree-column spinal osteotomies are common to restore sagittal balance. However, these procedures are challenging. Pelvic osteotomies may be a feasible alternative, although instability and compromised correction are concerning, which dome-shaped osteotomies may mitigate. As a possible and novel alternative for spinal osteotomies, pelvic dome and open wedge osteotomies for correction of sagittal spine balance were compared. Four in-silico pelvic osteotomies were performed on 3D CT-reconstructions: bilateral extending pelvic osteotomy (BEPO) and dome pelvic osteotomies (DPOs) around center of the sacral endplate (SE-DPO), sacroiliac joints (SI-DPO) and centers of the acetabula (A-DPO). We measured pelvic extension and bone contact surface (BCS) after 10°, 15° and 20° extension and the length of the sacropelvic ligaments after 20° extension. In radiographs of five samples of failed back surgery, we measured the effect on sagittal vertical axis (SVA) and Th1 pelvic angle (TPA). Pelvic extension was similar for all types of osteotomy. After 20° extension, BCS was 34.1 % (SE-DPO), 28.2 % (SI-DPO) and 30.6 % (A-DPO). Average shortening of the spinopelvic ligaments was 2.3 % after the BEPO, 22.0 % after SE-SPO, 17.0 % after SI-DPO and 11.8 % after A-DPO. After 15° correction, SVA correction was 12.6 cm and TPA correction 5.8° after BEPO. After SE-DPO, the correction was 14.5 cm and 14.1°, after SI-DPO 13.4 cm and 13.0° and after A-DPO 12.6 cm and 0.0°. A-DPO appeared to the most predictable and reliable pelvic osteotomy. However, this is technically demanding and shortens the pelvic floor ligaments. BEPO is less demanding with minimal effect on the ligaments, however it requires more complex stabilization methods. Feasibility and safety tests are required as a next step.</p
Real-Time Deep-Learning Image Reconstruction and Instrument Tracking in MR-Guided Biopsies
No full textBackground: Transrectal in-bore MR-guided biopsy (MRGB) is accurate but time-consuming, limiting clinical throughput. Faster imaging could improve workflow and enable real-time instrument tracking. Existing acceleration methods often use simulated data and lack validation in clinical settings. Purpose: To accelerate MRGB by using deep learning for undersampled image reconstruction and instrument tracking, trained on multi-slice MR DICOM images and evaluated on raw k-space acquisitions. Study Type: Prospective feasibility study. Population: Briefly, 1289 male patients (aged 44–87, median age 68) for model training, 8 male patients (aged 59–78, median age 65) for prospective feasibility testing. Field Strength/Sequence: 2D Cartesian balanced steady-state free precession, 3 T. Assessment: Segmentation and reconstruction models were trained on 8464 MRGB confirmation scans containing a biopsy needle guide instrument and evaluated on 10 prospectively acquired dynamic k-space samples. Needle guide tracking accuracy was assessed using instrument tip prediction (ITP) error, computed per frame as the Euclidean distance from reference positions defined via pre- and post-movement scans. Feasibility was measured by the proportion of frames with < 5 mm error. Additional experiments tested model robustness under increasing undersampling rates. Statistical Tests: In a segmentation validation experiment, a one-sample t-test tested if the mean ITP error was below 5 mm. Statistical significance was defined as p < 0.05. In the tracking experiments, the mean, standard deviation, and Wilson 95% CI of the ITP success rate were computed per sample, across undersampling levels. Results: ITP was first evaluated independently on 201 fully sampled scans, yielding an ITP error of 1.55 ± 1.01 mm (95% CI: 1.41–1.69). Tracking performance was assessed across increasing undersampling factors, achieving high ITP success rates from 97.5% ± 5.8% (68.8%–99.9%) at 8× up to 92.5% ± 10.3% (62.5%–98.9%) at 16× undersampling. Performance declined at 18×, dropping to 74.6% ± 33.6% (43.8%–91.7%). Data Conclusion: Results confirm stable needle guide tip prediction accuracy and support the robustness of the reconstruction model for tracking at high undersampling. Evidence Level: 2. Technical Efficacy: Stage 2.</p
800Gbps/λ WDM Metro-Access Network by novel photonic integrated EDWA and SOA-based WSS Nodes
No full textWe demonstrate the first high-capacity 800Gbps single-channel WDM metro-access network using photonic-integrated EDWA and 1×4 SOA-based WSS nodes. Results confirm dynamic add/drop switch over multiple nodes with 2.5dB OSNR penalty and 10dB OSNR margin.</p