275003 research outputs found
Sort by
Antimicrobial activity of silver free powder coatings based on biocomponents
No full textIn this work, silver-free, low-temperature-curing epoxy powder coatings with antimicrobial functionality were developed. The cationic biopolymer ε-polylysine (PLY) in its protonated form, as well as its intercalation and co-intercalation products with aminododecanoic acid (ADA) in montmorillonite (MMT), were employed as environmentally friendly bioactive additives. The powder coatings were formulated using epoxy resin and a highly reactive phenolic curing agent and subsequently applied onto steel substrates. The resulting materials were comprehensively characterized in terms of surface morphology, gloss, hardness, adhesion, and wettability. The coating showed a water contact angle of approximately 85°and an antibacterial reduction exceeding 99% against E. coli and S. aureus under laboratory conditions (ISO 22196). Antimicrobial activity is most likely associated with electrostatic interaction between the cationic PLY and bacterial membranes. Overall, this study suggests a promising and sustainable, silver-free strategy for developing antimicrobial powder coatings that may be suitable for hygiene sensitive environments, pending further long-term and safety evaluation.1
A methodical approach to evaluate the potential of Quantum Computing for Manufacturing Simulations
No full text986991In this paper, a methodical approach to evaluate the potential of quantum computing for manufacturing simulation, using the example of multi-axis milling of thin-walled aerospace components, is discussed. A developed approach for identifying bottlenecks in manufacturing simulations, for which the application of quantum computing potentially provides a speed-up or increase in accuracy, is presented. Moreover, indicators of quantum computing suitability and feasibility are defined with the main objective of identifying whether a manufacturing simulation bottleneck is suitable for quantum computing applications. First results of testing a hybrid routine as an application approach for the milling dynamics simulation on quantum machines are presented.13
How ceramides affect the development of colon cancer: from normal colon to carcinoma
No full text18031816The integrity of the colon and the development of colon cancer depend on the sphingolipid balance in colon epithelial cells. In this review, we summarize the current knowledge on how ceramides and their complex derivatives influence normal colon development and colon cancer development. Ceramides, glucosylceramides and sphingomyelin are essential membrane components and, due to their biophysical properties, can influence the activation of membrane proteins, affecting protein–protein interactions and downstream signalling pathways. Here, we review the cellular mechanisms known to be affected by ceramides and their effects on colon development. We also describe which ceramides are deregulated during colorectal carcinogenesis, the molecular mechanisms involved in ceramide deregulation and how this affects carcinogenesis. Finally, we review new methods that are now state of the art for studying lipid-protein interactions in the physiological environment.4761
Transferable calibration coefficients for semi-quantitative analysis by Laser Induced Breakdown Spectroscopy (LIBS) in samples containing calcium
No full textThis work establishes a framework for testing and developing calibration coefficients for multi-elemental analysis by LIBS, that are transferrable to various instruments under specific experimental conditions: measurements in air, full optical collection of the plasma plume, apparent plasma temperature and electron density within 6500-7500 K and 1-2 × 1017 cm-3, respectively. Here, the plasma was produced by ns laser pulses at 1064 nm, with energy of 30 mJ while for its detection we used high resolution compact spectrometers. Calibration coefficients for 14 elements were derived respect to one Ca I line (443.50 nm) considering that Ca is a common element in natural samples. The calibration coefficients were obtained from: (i) extrapolated linear peak growths, produced by changing the sample mass on a solid support (Si wafer or Al); (ii) peaks normalized on the Ca line. Their validity interval is specified while the inherent variations with the element abundance and plasma parameters are explained. The initial calibration involved nine different samples, including a multi-element standard, rock, soils ash, coal, and carbonate's mixture, while the validation was applied on two soil samples, both in form of particles on wafer and pressed into pellets. Calibration coefficients based on the linear slope produced quantification of 13 elements within accuracy of ±30% while the use of the line ratios increased the error for some considered elements. To facilitate transfer of the coefficients to other experiments, we provide practical instructions and limits of applicability. The transition from relative to absolute element concentration measurements is also explained in the text.23
Vectorial Micro Scanning Mirror for Fast Beam Positioning of a Compact Medical Therapy Laser
No full textMiniaturized vectorial beam steering mirrors are required in numerous applications like (i) LIDAR, (ii) diagnostic imaging or (iii) miniaturized therapeutic laser systems. In this article we present a new type of electrostatically driven vectorial (2D quasi-static) MEMS scanning mirror with monolithic integrated position sensors. The vectorial MEMS scanner was specially optimized for the requirements of a compact therapeutic photocoagulation laser system for the treatment of retinal eye diseases. This requires a highly miniaturized MEMS scanning system for fast and precise vectorial beam positioning of the treatment laser with a positioning time of ≤ 5 ms. The quasi-static 2D drive of the presented 2D MEMS scanning mirror is based on electrostatic vertical comb actuators in combination with a non-cardanic suspension of the 2.2 mm circular mirror plate. To measure and control the actual beam position piezoresistive position sensors are monolithically integrated into the MEMS design. The MEMS scanner was designed for a quasi-static (mechanical) 2D tilt angle of ± 2 ° for both scan axes each in two frequency variants with 714 Hz and 1 kHz at 70 V and 130 V drive voltage, respectively. For high laser powers of > 1.5 W (average power) at 519 nm wavelength, highly reflective optical coatings based on a symmetric HRC design of enhanced (hybrid) Al with R ≥ 98 % are used
Temporal and Multivariate Similarity Clustering of 5G Performance Data
No full text114137114145The performance of 5G mobile network cells is highly impacted by their evolving configuration and temporal environmental conditions, such as the number of connected devices or resource utilization. Evaluation of the performance of such a system is a complex task that requires the simultaneous analysis of multiple indicators and inspires the research community to work on zero-touch network service management. In this paper, we present a novel time series clustering method - Temporal and Multivariate Similarity Clustering (TMSC) - that incorporates Dynamic Time Warping with Limited Warping Length and Spectral Clustering, allowing for radio cell grouping based on realization of multiple Key Performance Indicators. We evaluated TMSC against state-of-the-art algorithms at a practical task of identifying cell configuration differences by clustering their performance metrics with a limited set of observations. The proposed algorithm outperformed other methods regarding the Normalized Mutual Information score achieved for more than 95% of the cases studied. We also display the potential for method generalization by evaluating it at the hand gesture recognition task, which yields satisfactory results.1
Federated Learning with Integrated Over-the-Air Computation and Sensing in IRS-assisted Networks
No full text362367Network intelligence is a key feature to be implemented in future generation networks. Distributed learning schemes such as federated learning (FL) are considered as promising solutions to it while preserving users' privacy and security and saving communication burden. However, in the case of traditional cross-device FL where massive participating devices are considered, only few clients can participate in each communication round of FL training for efficiency. Overthe- air computation (OTA) is well-suited for alleviating this issue by allowing simultaneous transmission to directly obtain the computation results by the superposition property of the wireless channels. The performance of OTA which is significantly impacted by weak channel links could be saved by adapting the wireless environment by means of an intelligent reflecting surface (IRS). Network intelligence systematically requires being aware of the environment. The sensing functionality needs therefore to be included efficiently. Integrated communication and sensing (ISAC), which consists of using the communication signal for achieving sensing at the same time, could introduce additional interference to an FL system. Therefore, an FL system design with integrated OTA and sensing in IRS-assisted networks is investigated. A maximization problem of the number of participating clients has been proposed to optimize the learning performance. A solution based on alternative optimization and difference-of-convex (DC) programming is given. Simulation results confirmed the impact of including the sensing functionality and the role of IRS to the system design
Pruritus and Dysesthesia
No full text110127Pruritus is defined as an unpleasant sensation of the skin that elicits a desire to scratch. It is the most common skin-related symptom. In primary skin diseases, pruritus often accompanies the distinct skin lesions. For pruritus due to underlying systemic diseases (e.g. renal, hepatic, neoplastic, psychiatric) or drug intake, there may be no cutaneous findings or only secondary skin lesions due to scratching (e.g. prurigo nodularis, lichen simplex chronicus). This chapter provides an approach to the evaluation and treatment of patients with pruritus as a chief complaint. Regional forms of pruritus and dysesthesia are also reviewed, including those with neurologic etiologies. Although our incomplete understanding of the pathogenesis of pruritus has hampered therapeutic advances, recent discoveries provide hope for more effective treatments in the future.
Benetzungssteuerung und Klebvorbehandlung von Kunststoffen mittels Ultrakurzpulslaser
No full text10410
D-dimer levels decline after immunosuppressive treatment rather than anticoagulant treatment in severe autoimmune chronic spontaneous urticaria
No full text4244Chronic spontaneous urticaria (CSU) is a common dermatological condition presenting with wheals and/or angioedema for more than 6 weeks. The role of autoimmunity and inflammation in the pathogenesis of CSU have been studied, but the precise mechanism remains unknown. Association with coagulation cascade has been suggested based on the observations of increased coagulation indicators such as serum D-dimer levels. We report an omalizumab refractory case of severe CSU with high D-dimer levels that declined only after disease remission with cyclosporine treatment but not with anticoagulation. Activation of coagulation cascade occurs secondary to the pro-inflammatory state in CSU patients and the correlation between D-dimer levels and disease activity may indicate the need for more studies to better understand the relationship of D-dimer levels and omalizumab resistance. Clinicians should consider this relationship in CSU patients with significant D-dimer levels before considering treatment with anticoagulants.56