Refine
Year of publication
Institute
- Fachbereich Medizintechnik und Technomathematik (1563) (remove)
Has Fulltext
- no (1563) (remove)
Language
- English (1563) (remove)
Document Type
- Article (1311)
- Conference Proceeding (133)
- Book (43)
- Part of a Book (43)
- Doctoral Thesis (18)
- Other (6)
- Patent (4)
- Preprint (3)
- Habilitation (1)
- Talk (1)
Keywords
- LAPS (4)
- Natural language processing (4)
- CellDrum (3)
- Field-effect sensor (3)
- Light-addressable potentiometric sensor (3)
- Paired sample (3)
- hydrogen peroxide (3)
- impedance spectroscopy (3)
- Bacillus atrophaeus (2)
- Biocomposites (2)
- Boundary integral equations (2)
- Clustering (2)
- Conductive boundary condition (2)
- Empirical process (2)
- Force (2)
- Goodness-of-fit test (2)
- Incomplete data (2)
- Independence test (2)
- Information extraction (2)
- Iterative learning control (2)
- Limit analysis (2)
- Machine learning (2)
- Natural fibres (2)
- Parametric bootstrap (2)
- Polymer-matrix composites (2)
- Raman spectroscopy (2)
- Shakedown analysis (2)
- Stiffness (2)
- Stress concentrations (2)
- Transmission eigenvalues (2)
- biopotential electrodes (2)
- constructive alignment (2)
- damage (2)
- examination (2)
- field-effect sensor (2)
- frequency mixing magnetic detection (2)
- likelihood ratio test (2)
- locomotion (2)
- long-term retention (2)
- multimodal (2)
- muscle fascicle behavior (2)
- not identically distributed (2)
- practical learning (2)
- tobacco mosaic virus (TMV) (2)
- ultrasound (2)
- ultrasound imaging (2)
- (Bio)degradation (1)
- Acceleration (1)
- Achilles tendon (1)
- Active learning (1)
- Adaptive control (1)
- Afterload (1)
- Ageing (1)
- Agent-based simulation (1)
- AlterG (1)
- Alzheimer's disease (1)
- Anastomotic leakage (1)
- Anatomy (1)
- Annulus Fibrosus (1)
- Architectural gear ratio (1)
- Assistive technology (1)
- Asymptotic efficiency (1)
- Asymptotic relative efficiency (1)
- Autolysis (1)
- Automatic control (1)
- Bacillus atrophaeus spores (1)
- Bacillus sp (1)
- Balance (1)
- Biomechanical simulation (1)
- Biomolecular logic gate (1)
- Biosolubilization (1)
- Bladder (1)
- Bone sawing (1)
- Booster Station (1)
- Bootstrap (1)
- Bootstrapping (1)
- Boundary integral equations, (1)
- Brownian Pillow (1)
- CNOT (1)
- Calorimetric gas sensor (1)
- Capacitive field-effect (1)
- Capacitive model (1)
- Cardiac myocytes (1)
- Cardiac tissue (1)
- Categorial variable (1)
- Cell permeability (1)
- Cellular force (1)
- Cementoblast (1)
- Censored data (1)
- Chance constrained programming (1)
- Chemical images (1)
- Chemical imaging (1)
- Chemical imaging sensor (1)
- Chemical sensor (1)
- Circular Dichroism (1)
- Cloud Computing (1)
- Cloud Service Broker (1)
- Co-managed care (1)
- Coat protein (1)
- Coefficient of ocular rigidity (1)
- Collective risk model (1)
- Competitiveness (1)
- Complex System (1)
- Complex-valued eigenvalues (1)
- Compliance (1)
- Compression (1)
- Computational biomechanics (1)
- Concomitant (1)
- Conductive Boundary Condition (1)
- Conservation laws (1)
- Constitutive model (1)
- Contractile tension (1)
- Contractility (1)
- Corneo-scleral shell (1)
- Coverage probability (1)
- Cramér-von-Mises statistic (1)
- Cramér-von-Mises test (1)
- Cross border adjustment mechanism (1)
- Crámer–von-Mises distance (1)
- C–V method (1)
- DNA (1)
- DNA biosensor (1)
- DNA hybridization (1)
- DPA (dipicolinic acid) (1)
- Damage mechanics theory (1)
- Decomposition (1)
- Deep learning (1)
- Dehydrogenase (1)
- Diaphorase (1)
- Differential tonometry (1)
- Dimensional splitting (1)
- Disc Degeneration (1)
- Discontinuous fractures (1)
- Discrete Optimization (1)
- Drug simulation (1)
- Dry surfaces (1)
- E-Mobility (1)
- EEG (1)
- EIS capacitive sensor (1)
- ES-FEM (1)
- Eigenvalue trajectories (1)
- Elderly (1)
- Electrolyte–insulator–semiconductor (1)
- Electromagnetism (1)
- Electromechanical modeling (1)
- Elemental (1)
- End-to-end colorectal anastomosis (1)
- Endothelial cells (1)
- Endothelial dysfunction (1)
- Energy market design (1)
- Energy-intensive industry (1)
- Entropy solution (1)
- Enzymatic biosensor (1)
- Enzyme biosensor (1)
- Enzyme coverage (1)
- Enzyme logic gate (1)
- Enzyme nanocarrier (1)
- Equivalence test (1)
- Esophageal Doppler monitor (1)
- Evolution of damage (1)
- Exponential Euler scheme, (1)
- Exponential time differencing (1)
- Extension fracture (1)
- Extension strain criterion (1)
- External knee adduction moments (1)
- Eyeball (1)
- FGF23 (1)
- FS-FEM (1)
- Fall prevention (1)
- Field effect (1)
- Field-effect biosensor (1)
- Field-effect device (1)
- Finite difference methods (1)
- Finite element analysis (1)
- Finite element analysis (FEA) (1)
- Finite element modelling (1)
- Floor prices (1)
- Forces (1)
- Fracture configuration (1)
- Fracture simulation (1)
- Freeze–thaw process (1)
- Frequency adaption (1)
- Frequency mixing magnetic detection (1)
- Functional Delta Method (1)
- Gamma distribution (1)
- Glaucoma (1)
- Glucose biosensor (1)
- Glucose oxidase (1)
- Gold nanoparticle (1)
- Goodness-of-fit tests for uniformity (1)
- Grid Computing (1)
- Ground-level falls (1)
- Growth modelling (1)
- Hadamard differentiability (1)
- Haemodialysis (1)
- Handbike (1)
- Heart tissue culture (1)
- Helmholtz equation (1)
- Heterostructure (1)
- Higher-order codes (1)
- Hodgkin–Huxley models (1)
- Hoeffding-Blum-Kiefer-Rosenblatt independence test (1)
- Homogenization (1)
- Hotelling’s T² test (1)
- Human-Computer interaction (1)
- Hydrogen peroxide (1)
- Image Reconstruction (1)
- Impedance Spectroscopy (1)
- Impedance spectroscopy (1)
- Implicit methods (1)
- Induced pluripotent stem cells (1)
- Information Extraction (1)
- Inotropic compounds (1)
- Integrated empirical distribution (survival) function (1)
- Interior Neumann eigenvalues (1)
- Interior transmission eigenvalues (1)
- Interior transmission problem (1)
- Intervertebral Disc (1)
- Intradiscal Pressure (1)
- Inverse Scattering (1)
- Inverse dynamic problem (1)
- Inverse kinematic problem (1)
- Inverse scattering (1)
- Inverse spectral problem (1)
- Ion channels (1)
- Kinetic energy (1)
- Klotho (1)
- Knee (1)
- LPS (1)
- Lab-on-Chip (1)
- Label-free detection (1)
- Langevin theory (1)
- Layer-by-layer adsorption (1)
- LbL films (1)
- Light-addressable Potentiometric Sensor (1)
- Lipopolysaccharide (1)
- Liver (1)
- Load modeling (1)
- Long COVID (1)
- MOS (1)
- Magnetic nanoparticles (1)
- Manipulated variables (1)
- Marginal homogeneity (1)
- Marginal homogeneity test (1)
- Market modeling (1)
- Matrix exponential (1)
- Mechanical simulation (1)
- Mechanotransduction (1)
- Metascintillator (1)
- Microbial adhesion (1)
- Microcirculation (1)
- Micromagnetic simulation (1)
- Mild cognitive impairment (1)
- Mobility (1)
- Mobility tests (1)
- Mobility transition (1)
- Mohr–Coulomb criterion (1)
- Monotone methods (1)
- Multi-criteria decision analysis (1)
- Multi-dimensional partial differential equations (1)
- Multi-sample problem (1)
- Multianalyte detection (1)
- Multimode failure (1)
- Multiple TOF kernels (1)
- Muscle (1)
- Muscle Fascicle (1)
- Muscle Force (1)
- Muscle fibers (1)
- Musculoskeletal model (1)
- Musculoskeletal system (1)
- Myocardial infarction and cardiac death (1)
- NONOate (1)
- Natural Language Processing (1)
- Natural language understanding (1)
- Negative impedance convertor (1)
- Neural Network (1)
- Niacin (1)
- Nitric Oxide (1)
- Nitric Oxide Donor (1)
- Non-linear optimization (1)
- Non-parallel fissures (1)
- Nonequilibrium dynamics (1)
- Nonlinear Dynamics (1)
- Nonlinear PDEs (1)
- Nonlinear eigenvalue problems (1)
- Nucleus Pulposus (1)
- Numerical inversion of Laplace transforms (1)
- Numerical linear algebra (1)
- Numerics (1)
- O2 plasma (1)
- Ocular blood flow (1)
- Organic light-emitting diode display (1)
- PTH (1)
- Parabolic SPDEs (1)
- Paralympic sport (1)
- Passive stretching (1)
- Pelvic floor dysfunction (1)
- Pelvic muscle (1)
- Penicillin (1)
- Pharmacology (1)
- Phosphate (1)
- Physiology (1)
- Poly(allylamine hydrochloride) (1)
- Poly(d,l-lacticacid) (1)
- Polyimide (1)
- Post-COVID-19 syndrome (1)
- Potential theory (1)
- Potentiometry (1)
- Preference assessment (1)
- Pressure-volume relationship (1)
- Process model (1)
- Product-integration (1)
- Profile Extraction (1)
- Profile extraction (1)
- Proximal humerus fracture (1)
- Pulsations (1)
- Pump System (1)
- Query learning (1)
- RVA (1)
- Reaction-diffusion systems (1)
- Real distinct pole (1)
- Real-time monitoring (1)
- Recombinant activated protein C (1)
- Reconstruction (1)
- Regionalization (1)
- Rehabilitation Technology and Prosthetics (1)
- Rehabilitation engineering (1)
- Relation classification (1)
- Reliability analysis (1)
- Reliability of structures (1)
- Reproducible research (1)
- Resampling test (1)
- Resolvent Operator (1)
- Resonance-mode measurement (1)
- Retinal vessel analysis (1)
- Retinal vessels (1)
- Riboflavin (1)
- Robotic rehabilitation (1)
- Rotator cuff (1)
- Running (1)
- S-FEM (1)
- Sampling methods (1)
- ScaLAPACK (1)
- Semi-parametric random censorship model (1)
- Septic cardiomyopathy (1)
- Simulation (1)
- Simultaneous determination (1)
- Sleep EEG (1)
- Sn₃O₄ (1)
- Source term (1)
- Spleen (1)
- Steel industry (1)
- Sterilisation process (1)
- Stochastic programming (1)
- Surface microorganisms (1)
- Surgical Navigation and Robotics (1)
- Surgical staplers (1)
- Survival analysis (1)
- Swabbing (1)
- TMV adsorption (1)
- TOF PET (1)
- Ta₂O₅ gate (1)
- Technical Operations Research (TOR) (1)
- Tendon Rupture (1)
- Tendon properties (1)
- Tension (1)
- Text Mining (1)
- Text mining (1)
- Thiamine (1)
- Tinetti test (1)
- Tobacco mosaic virus (1)
- Tobacco mosaic virus (TMV) (1)
- Training (1)
- Transmission Eigenvalues (1)
- Trustworthy artificial intelligence (1)
- Uniaxial compression test (1)
- Ureter (1)
- Vapnik–Čhervonenkis class (1)
- Variable height stapler design (1)
- Vascular response (1)
- Vasomotions (1)
- Velocity (1)
- Visual field asymmetry (1)
- Vitamin A (1)
- Vitamin B (1)
- Vitamin D (1)
- Volterra integral equation (1)
- Volume of confidence regions (1)
- Volume status (1)
- Volumes of confidence regions (1)
- Workflow (1)
- Workflow Orchestration (1)
- XOR (1)
- acetoin (1)
- achilles tendon (1)
- actin cytoskeleton (1)
- adipose-derived stromal cells (ASCs) (1)
- adsorption (1)
- agility (1)
- allocation (1)
- anaesthetic complications (1)
- anisotropy (1)
- annealing (1)
- aortic perfusion (1)
- aquaculture (1)
- artificial olfactory image (1)
- asymptotic relative efficiency (1)
- barium strontium titanate (1)
- biaxial tensile experiment (1)
- biomechanics (1)
- biosensor (1)
- biosensors (1)
- bootstrap (1)
- calorimetric gas sensor (1)
- calorimetric gas sensor;hydrogen peroxide;wireless sensor system (1)
- capacitive field-effect biosensor (1)
- capacitive field-effect sensor (1)
- carbonized rice husk (1)
- cardiomyocyte biomechanics (1)
- catalytic metal (1)
- cell aerosolization (1)
- cell atomization (1)
- central symmetry test (1)
- cerebral small vessel disease (1)
- chance constrained programming (1)
- chemical sensor (1)
- chip-based sensor setup (1)
- cognitive impairment (1)
- community dwelling (1)
- complete block symmetry (1)
- computational fluid dynamics analysis (1)
- conditional excess distribution (1)
- conditional expectation principle (1)
- confidence interval (1)
- connective tissue (1)
- constitutive modeling (1)
- contactless conductivity sensor (1)
- correlation (1)
- coupled Néel–Brownian relaxation dynamics (1)
- covariance principle (1)
- dental trauma (1)
- dialysis (1)
- difficult airway (1)
- distorted element (1)
- double-lumen tube intubation (1)
- drop jump (1)
- eigensolvers (1)
- elastic scattering (1)
- electrical conductivity of liquids (1)
- electrolyte-insulator semiconductor sensor (EIS) (1)
- electromyography (1)
- electronic nose (1)
- endoluminal (1)
- endospores (1)
- energy absorption (1)
- energy dissipation (1)
- enzymatic (bio)degradation (1)
- enzyme cascade (1)
- enzyme immobilization (1)
- exchangeability test (1)
- extracorporeal membrane oxygenation (1)
- field-effect structure (1)
- force generation (1)
- forecast (1)
- forehead EEG (1)
- frequency mixing (1)
- functional data (1)
- gait (1)
- gas sensor (1)
- glucose oxidase (GOx) (1)
- goodness-of-fit test (1)
- healthy aging (1)
- heavy metals (1)
- hiPS cardiomyocytes (1)
- high-intensity exercise (1)
- high-k material (1)
- horseradish peroxidase (HRP) (1)
- huge dimensional data (1)
- humic acid (1)
- hydroxylation (1)
- hyper-gravity (1)
- hyperelastic (1)
- hypo-gravity (1)
- immobilization (1)
- in-ear EEG (1)
- in-situ monitoring (1)
- independence test (1)
- intraclass correlation coefficient (1)
- key performance indicators (1)
- lable-free detection (1)
- light-addressable potentiometric sensor (1)
- light-addressing technologies (1)
- lignite (1)
- limit analysis (1)
- lipopolysaccharide (1)
- magnetic actuation (1)
- magnetic beads (1)
- magnetic biosensing (1)
- magnetic nanoparticles (1)
- magnetic relaxation (1)
- magnetic sandwich immunoassay (1)
- magnetic sensing (1)
- magnetic separation (1)
- magnetic tweezers (1)
- magnetophoretic velocity (1)
- mechanical buffer (1)
- metal-oxide-semiconductor structure (1)
- method of fundamental solutions (1)
- microfluidics (1)
- micromagnetic simulation (1)
- multi-functional material (1)
- multinomial distribution (1)
- multiparametric immunoassays (1)
- multivariate normal distribution (1)
- muscle mechanics (1)
- nanobelts (1)
- non-simplex S-FEM elements (1)
- novel photoexcitation method (1)
- optical sensor setup (1)
- optical spore trapping (1)
- optical trapping (1)
- organosilanes (1)
- overload (1)
- parabolic flight (1)
- performance analysis (1)
- performance testing (1)
- physiology (1)
- plant virus detection (1)
- plug-based microfluidic device (1)
- poly(d, l-lactic acid) (1)
- portfolio risk (1)
- prevention (1)
- psychosocial (1)
- random effects (1)
- random effects meta-regression model (1)
- rehabilitation (1)
- reliability of structures (1)
- retinal microvasculature (1)
- retinal vessels (1)
- running (1)
- sEMG (1)
- sarcomere operating length (1)
- scanned light pulse technique (1)
- sensors (1)
- separable Hilbert space (1)
- series elastic element behavior (1)
- shakedown analysis (1)
- shoulder (1)
- silanization (1)
- simulation (1)
- smooth muscle contraction (1)
- spatial resolution (1)
- sprint start (1)
- standard error of measurement (1)
- sterilisation (1)
- sterilization (1)
- sterilization conditions (1)
- stiffness (1)
- stochastic programming (1)
- strain energy function (1)
- stretch reflex (1)
- stretch-shortening cycle (1)
- superparamagnetic bead (1)
- superparamagnetic nanoparticles (1)
- surface functionalization (1)
- surface modification (1)
- survival (1)
- temperature (1)
- tendon rupture (1)
- test-retest reliability (1)
- thermometry (1)
- tilted constant illumination (1)
- training simulator (1)
- tri-lineage differentiation (1)
- turnip vein clearing virus (TVCV) (1)
- twin-fluid atomizer (1)
- ultrasonography (1)
- uniformly most powerful invariant test (1)
- unloading (1)
- videolaryngoscopy (1)
- virgin passive (1)
- virtual reality (1)
- viscoelasticity (1)
- visualization (1)
- walking (1)
- walking gait (1)
The network approach towards the analysis of the dynamics of complex systems has been successfully applied in a multitude of studies in the neurosciences and has yielded fascinating insights. With this approach, a complex system is considered to be composed of different constituents which interact with each other. Interaction structures can be compactly represented in interaction networks. In this contribution, we present a brief overview about how interaction networks are derived from multivariate time series, about basic network characteristics, and about challenges associated with this analysis approach.
The concept of an injective affine embedding of the quantum states into a set of classical states, i.e., into the set of the probability measures on some measurable space, as well as its relation to statistically complete observables is revisited, and its limitation in view of a classical reformulation of the statistical scheme of quantum mechanics is discussed. In particular, on the basis of a theorem concerning a non-denseness property of a set of coexistent effects, it is shown that an injective classical embedding of the quantum states cannot be supplemented by an at least approximate classical description of the quantum mechanical effects. As an alternative approach, the concept of quasi-probability representations of quantum mechanics is considered.
Messenger apps like WhatsApp and Telegram are frequently used for everyday communication, but they can also be utilized as a platform for illegal activity. Telegram allows public groups with up to 200.000 participants. Criminals use these public groups for trading illegal commodities and services, which becomes a concern for law enforcement agencies, who manually monitor suspicious activity in these chat rooms. This research demonstrates how natural language processing (NLP) can assist in analyzing these chat rooms, providing an explorative overview of the domain and facilitating purposeful analyses of user behavior. We provide a publicly available corpus of annotated text messages with entities and relations from four self-proclaimed black market chat rooms. Our pipeline approach aggregates the extracted product attributes from user messages to profiles and uses these with their sold products as features for clustering. The extracted structured information is the foundation for further data exploration, such as identifying the top vendors or fine-granular price analyses. Our evaluation shows that pretrained word vectors perform better for unsupervised clustering than state-of-the-art transformer models, while the latter is still superior for sequence labeling.
We consider recent reports on small-world topologies of interaction networks derived from the dynamics of spatially extended systems that are investigated in diverse scientific fields such as neurosciences, geophysics, or meteorology. With numerical simulations that mimic typical experimental situations, we have identified an important constraint when characterizing such networks: indications of a small-world topology can be expected solely due to the spatial sampling of the system along with the commonly used time series analysis based approaches to network characterization.
Light-addressable potentiometric sensors (LAPS) are semiconductor-based potentiometric sensors, with the advantage to detect the concentration of a chemical species in a liquid solution above the sensor surface in a spatially resolved manner. The addressing is achieved by a modulated and focused light source illuminating the semiconductor and generating a concentration-depending photocurrent. This work introduces a LAPS set-up that is able to monitor the electrical impedance in addition to the photocurrent. The impedance spectra of a LAPS structure, with and without illumination, as well as the frequency behaviour of the LAPS measurement are investigated. The measurements are supported by electrical equivalent circuits to explain the impedance and the LAPS-frequency behaviour. The work investigates the influence of different parameters on the frequency behaviour of the LAPS. Furthermore, the phase shift of the photocurrent, the influence of the surface potential as well as the changes of the sensor impedance will be discussed.
Useful market simulations are key to the evaluation of diferent market designs existing of multiple market mechanisms or rules. Yet a simulation framework which has a comparison of diferent market mechanisms in mind was not found. The need to create an objective view on different sets of market rules while investigating meaningful agent strategies concludes that such a simulation framework is needed to advance the research on this subject. An overview of diferent existing market simulation models is given which also shows the research gap and the missing capabilities of those systems. Finally, a methodology is outlined how a novel market simulation which can answer the research questions can be developed.
Flow visualization by means of PIV of an artificial aortic heart valve fixed into a mock aorta
(2005)
In this study, flexible calorimetric gas sensors are developed for specificdetection of gaseous hydrogen peroxide (H₂O₂) over a wide concentrationrange, which is used in sterilization processes for aseptic packaging industry.The flexibility of these sensors is an advantage for identifying the chemical components of the sterilant on the corners of the food boxes, so-called “coldspots”, as critical locations in aseptic packaging, which are of great importance. These sensors are fabricated on flexible polyimide films by means of thin-film technique. Thin layers of titanium and platinum have been deposited on polyimide to define the conductive structures of the sensors. To detect the high-temperature evaporated H₂O₂, a differential temperature set-up is proposed. The sensors are evaluated in a laboratory-scaled sterilizationsystem to simulate the sterilization process. The concentration range of the evaporated H₂O₂ from 0 to 7.7% v/v was defined and the sensors have successfully detected high as well as low H₂O₂ concentrations with a sensitivity of 5.04 °C/% v/v. The characterizations of the sensors confirm their precise fabrication, high sensitivity and the novelty of low H₂O₂ concentration detections for future inline monitoring of food-package sterilization.
The impact of surgical staplers on tissues has been studied mostly in an empirical manner. In this paper, finite element method was used to clarify the mechanics of tissue stapling and associated phenomena. Various stapling modalities and several designs of circular staplers were investigated to evaluate the impact of the device on tissues and mechanical performance of the end-to-end colorectal anastomosis. Numerical simulations demonstrated that a single row of staples is not adequate to resist leakage due to non-linear buckling and opening of the tissue layers between two adjacent staples. Compared to the single staple row configuration, significant increase in stress experienced by the tissue at the inner staple rows was observed in two and three rows designs. On the other hand, adding second and/or third staple row had no effect on strain in the tissue inside the staples. Variable height design with higher staples in outer rows significantly reduced the stresses and strains in outer rows when compared to the same configuration with flat cartridge.
A light-addressable potentiometric sensor (LAPS) can measure the concentration of one or several analytes at the sensor surface simultaneously in a spatially resolved manner. A modulated light pointer stimulates the semiconductor structure at the area of interest and a responding photocurrent can be read out. By simultaneous stimulation of several areas with light pointers of different modulation frequencies, the read out can be performed at the same time. With the new proposed controller electronic based on a field-programmable gate array (FPGA), it is possible to control the modulation frequencies, phase shifts, and light brightness of multiple light pointers independently and simultaneously. Thus, it is possible to investigate the frequency response of the sensor, and to examine the analyte concentration by the determination of the surface potential with the help of current/voltage curves and phase/voltage curves. Additionally, the ability to individually change the light intensities of each light pointer is used to perform signal correction.
Coronavirus disease 2019 (COVID-19) is a novel human infectious disease provoked by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Currently, no specific vaccines or drugs against COVID-19 are available. Therefore, early diagnosis and treatment are essential in order to slow the virus spread and to contain the disease outbreak. Hence, new diagnostic tests and devices for virus detection in clinical samples that are faster, more accurate and reliable, easier and cost-efficient than existing ones are needed. Due to the small sizes, fast response time, label-free operation without the need for expensive and time-consuming labeling steps, the possibility of real-time and multiplexed measurements, robustness and portability (point-of-care and on-site testing), biosensors based on semiconductor field-effect devices (FEDs) are one of the most attractive platforms for an electrical detection of charged biomolecules and bioparticles by their intrinsic charge. In this review, recent advances and key developments in the field of label-free detection of viruses (including plant viruses) with various types of FEDs are presented. In recent years, however, certain plant viruses have also attracted additional interest for biosensor layouts: Their repetitive protein subunits arranged at nanometric spacing can be employed for coupling functional molecules. If used as adapters on sensor chip surfaces, they allow an efficient immobilization of analyte-specific recognition and detector elements such as antibodies and enzymes at highest surface densities. The display on plant viral bionanoparticles may also lead to long-time stabilization of sensor molecules upon repeated uses and has the potential to increase sensor performance substantially, compared to conventional layouts. This has been demonstrated in different proof-of-concept biosensor devices. Therefore, richly available plant viral particles, non-pathogenic for animals or humans, might gain novel importance if applied in receptor layers of FEDs. These perspectives are explained and discussed with regard to future detection strategies for COVID-19 and related viral diseases.
The artificial olfactory image was proposed by Lundström et al. in 1991 as a new strategy for an electronic nose system which generated a two-dimensional mapping to be interpreted as a fingerprint of the detected gas species. The potential distribution generated by the catalytic metals integrated into a semiconductor field-effect structure was read as a photocurrent signal generated by scanning light pulses. The impact of the proposed technology spread beyond gas sensing, inspiring the development of various imaging modalities based on the light addressing of field-effect structures to obtain spatial maps of pH distribution, ions, molecules, and impedance, and these modalities have been applied in both biological and non-biological systems. These light-addressing technologies have been further developed to realize the position control of a faradaic current on the electrode surface for localized electrochemical reactions and amperometric measurements, as well as the actuation of liquids in microfluidic devices.
Field-effect capacitive electrolyte-insulator-semiconductor (EIS) sensors functionalised with citrate-capped gold nanoparticles (AuNP) have been used for the electrostatic detection of macromolecules by their intrinsic molecular charge. The EIS sensor detects the charge changes in the AuNP/macromolecule hybrids induced by the adsorption or binding events. A feasibility of the proposed detection scheme has been exemplary demonstrated by realising EIS sensors for the detection of poly-D-lysine molecules.
A field-effect biosensor employing tobacco mosaic virus (TMV) particles as scaffolds for enzyme immobilization is presented. Nanotubular TMV scaffolds allow a dense immobilization of precisely positioned enzymes with retained activity. To demonstrate feasibility of this new strategy, a penicillin sensor has been developed by coupling a penicillinase with virus particles as a model system. The developed field-effect penicillin biosensor consists of an Al-p-Si-SiO₂-Ta₂O₅-TMV structure and has been electrochemically characterized in buffer solutions containing different concentrations of penicillin G. In addition, the morphology of the biosensor surface with virus particles was characterized by scanning electron microscopy and atomic force microscopy methods. The sensors possessed a high penicillin sensitivity of ~ 92 mV/dec in a nearly-linear range from 0.1 mM to 10 mM, and a low detection limit of about 50 µM. The long-term stability of the penicillin biosensor was periodically tested over a time period of about one year without any significant loss of sensitivity. The biosensor has also been successfully applied for penicillin detection in bovine milk samples.
The structure of the female pelvic floor (PF) is an inter-related system of bony pelvis,muscles, pelvic organs, fascias, ligaments, and nerves with multiple functions. Mechanically, thepelvic organ support system are of two types: (I) supporting system of the levator ani (LA) muscle,and (II) the suspension system of the endopelvic fascia condensation [1], [2]. Significantdenervation injury to the pelvic musculature, depolimerization of the collagen fibrils of the softvaginal hammock, cervical ring and ligaments during pregnancy and vaginal delivery weakens thenormal functions of the pelvic floor. Pelvic organ prolapse, incontinence, sexual dysfunction aresome of the dysfunctions which increases progressively with age and menopause due toweakened support system according to the Integral theory [3]. An improved 3D finite elementmodel of the female pelvic floor as shown in Fig. 1 is constructed that: (I) considers the realisticsupport of the organs to the pelvic side walls, (II) employs the improvement of our previous FEmodel [4], [5] along with the patient based geometries, (III) incorporates the realistic anatomy andboundary conditions of the endopelvic (pubocervical and rectovaginal) fascia, and (IV) considersvarying stiffness of the endopelvic fascia in the craniocaudal direction [3]. Several computationsare carried out on the presented computational model with healthy and damaged supportingtissues, and comparisons are made to understand the physiopathology of the female PF disorders.
This paper develops a new finite element method (FEM)-based upper bound algorithm for limit and shakedown analysis of hardening structures by a direct plasticity method. The hardening model is a simple two-surface model of plasticity with a fixed bounding surface. The initial yield surface can translate inside the bounding surface, and it is bounded by one of the two equivalent conditions: (1) it always stays inside the bounding surface or (2) its centre cannot move outside the back-stress surface. The algorithm gives an effective tool to analyze the problems with a very high number of degree of freedom. Our numerical results are very close to the analytical solutions and numerical solutions in literature.
A physically coupled finite element method (FEM) model is developed to study the response behavior of a calorimetric gas sensor. The modeled sensor serves as a monitoring device of the concentration of gaseous hydrogen peroxide (H2 O2) in a high temperature mixture stream in aseptic sterilization processes. The principle of operation of a calorimetric H2 O2 sensor is analyzed and the results of the numerical model have been validated by using previously published sensor experiments. The deviation in the results between the FEM model and experimental data are presented and discussed.
FEM shakedown analysis of structures under random strength with chance constrained programming
(2022)
Direct methods, comprising limit and shakedown analysis, are a branch of computational mechanics. They play a significant role in mechanical and civil engineering design. The concept of direct methods aims to determine the ultimate load carrying capacity of structures beyond the elastic range. In practical problems, the direct methods lead to nonlinear convex optimization problems with a large number of variables and constraints. If strength and loading are random quantities, the shakedown analysis can be formulated as stochastic programming problem. In this paper, a method called chance constrained programming is presented, which is an effective method of stochastic programming to solve shakedown analysis problems under random conditions of strength. In this study, the loading is deterministic, and the strength is a normally or lognormally distributed variable.