High Precision,Electrochemical Detection of Reversible Binding of Recombinant Proteins on Wide Bandgap GaN Electrodes Functionalized with Biomembrane Models

We report a novel hybrid charge sensor realized by the deposition of phospholipid monolayers on highly doped n‐GaN electrodes. To detect the binding of recombinant proteins with histidine‐tags, lipid vesicles containing chelator lipids were deposited on GaN electrodes pre‐coated with octadecyltrimethoxysilane monolayers. Owing to its optical transparency, GaN allows the confirmation of the fluidity of supported membranes by fluorescence recovery after photo‐bleaching (FRAP). The electrolyte‐(organic) insulator‐semiconductor (EIS) setup enables one to transduce variations in the surface charge density ΔQ into a change in the interface capacitance ΔC _p and, thus, the flat‐band potential ΔU _FB. The obtained results demonstrate that the membrane‐based charge sensor can reach a high sensitivity to detect reversible changes in the surface charge density on the membranes by the formation of chelator complexes, docking of eGFP with histidine tags, and cancellation by EDTA. The achievable resolution of ΔQ ≥ 0.1 μC/cm² is better than that obtained for membrane‐functionalized p‐GaAs, 0.9 μC/cm², and for ITO coated with a polymer supported lipid monolayer, 2.2 μC/cm². Moreover, we examined the potential application of optically active InGaN/GaN quantum dot structures, for the detection of changes in the surface potential from the photoluminescence signals measured at room temperature.     

Evaluation of process parameter space of bulk FinFETs using 3D TCAD

Using full 3D TCAD, an evaluation of process parameter space of bulk FinFET is presented from the point of view of DRAM, SRAM and I/O applications. Process and device simulations are performed with varying uniform fin doping, anti-punch implant dose and energy, fin width, fin height and gate oxide thickness. Bulk FinFET architecture with anti-punch implant is introduced beneath the channel region to reduce the punch-through and junction leakage. For 30 nm bulk FinFET, anti-punch implant with low energy of 15 to 25 keV and dose of 5.0 × 10¹³ to 1.0 × 10¹⁴ cm⁻² is beneficial to effectively suppress the punch-through leakage with reduced GIDL and short channel effects. Our simulations show that bulk FinFETs are approximately independent of back bias effect. With identical fin geometry, bulk FinFETs with anti-punch implant show same I_ON-I_OFF behavior and approximately equal short channel effects like SOI FinFETs.     

X-ray based tools for the investigation of buried interfaces in organic electronic devices

X-ray reflectivity combined with grazing incidence diffraction is a valuable tool for investigating organic multilayer structures that can be used in devices. We focus on a bilayer stack consisting of two materials (poly-(3-hexylthiophene)) (P3HT) and poly-(4-styrenesulfonic acid) (PSSA) spin cast from orthogonal solvents (water in the case of PSSA and chloroform or toluene for P3HT). X-ray reflectivity is used to determine the thickness of all layers as well as the roughness of the organic–organic hetero-interface and the P3HT surface. The surface roughness is found to be consistent with the results of atomic force microscopy measurements. For the roughness of P3HT/PSSA interface, we observe a strong dependence on the solvent used for P3HT deposition. The solvent also strongly impacts the texturing of the P3HT crystallites as revealed by grazing incidence diffraction. When applying the various PSSA/P3HT multilayers in organic thin-film transistors, we find an excellent correlation between the determined interface morphology, structure and the device performance.     

Emission Reduction and Capacity Increase in GSM Networks by Single Antenna Interference Cancellation

There is an increasing demand to utilize the frequency spectrum of mobile communication systems most efficiently. This means in particular to GSM networks that the frequency reuse shall be planned as low as possible. In this case the system may become limited by interference rather than coverage. One promising technology for GSM mobiles in interference-limited systems is single antenna interference cancellation (SAIC). This receiver technology allows both for increasing the network capacity and for reducing the base station transmit power. The aim of this paper is to assess the emission reduction as well as the system capacity capabilities when SAIC technology is applied in downlink receivers.     

MIMO systems with full and reduced hardware complexity

MIMO (multiple-input-multiple-output) systems propose enormous gains in the capacity of wireless systems without requiring more spectral resources. This paper first gives an overview of the use of MIMO for diversity and spatial multiplexing, and the use of channel state information in MIMO systems. It then explores the use of antenna selection as a means for the reduction of the hardware complexity. It is shown that the performance in a spatial-multiplexing application is almost as good as that of full-complexity systems as long as the number of RF chains is at least as large as the number of data streams.     

Nichtlineare Trajektorienfolgeregelung für einen Laborhelikopter

This contribution is devoted to the nonlinear tracking control problem of the laboratory experiment helicopter 3DOF distributed by Quanser. The laboratory experiment belongs to the class of mechanical systems with three degrees-of-freedom and two control inputs. It is well known that the systematic design of nonlinear controllers for underactuated mechanical systems is a challenge compared to fully actuated systems. On certain simplifying assumptions, which very well apply to the operating range of practical interest, we can show that the mathematical model is configuration flat. Thereby, a mechanical system is said to be configuration flat if it is differential flat and the flat outputs solely depend on the generalized coordinates of the mechanical system. The controller design is based on a formulation of the mechanical system on a Riemannian manifold where the kinetic energy serves as a natural Riemannian metric. In a first step a nonlinear tracking controller including an integral part in the linear error system is designed by means of a quasi-static state feedback. In a second step the design of the tracking controller is based on the theory of exact linearization utilizing the so-called dynamic extension algorithm. The experimental results of both controllers are compared and discussed in detail. In particular, the quasi-static state feedback controller shows an excellent tracking behavior. The performance as being obtained by the nonlinear controlled cannot be achieved by conventional linear control strategies.     

Ein Beitrag zur nichtlinearen Fahrdynamik-regelung: die differentielle Flachheit des Einspurmodells

This contribution is primarily concerned with the system analysis of the bicycle dynamics, revealing the differential flatness property as a main result. A physically relevant representative for the flat output is introduced, with its components given as the lateral and the longitudinal velocity of a distinguished point located on the longitudinal axis of the vehicle. This flatness property is shown for the front-, rear- and all-wheel driven vehicle, without referring to particular representatives of the functions modelling the lateral tire forces. Following the flatness based control theory, a novel approach to nonlinear vehicle dynamics control is discussed.     

Short- and long-term joint symbolic dynamics of heart rate and blood pressure in dilated cardiomyopathy

Autonomic cardiovascular control involves complex interactions of heart rate and blood pressure. In patients with dilated cardiomyopathy (DCM), this control is impaired and parameters for its quantification might be of prognostic importance. In this paper, we introduce methods based on joint symbolic dynamics (JSD) for the enhanced analysis of heart rate and blood pressure interactions. To assess the coarse-grained dynamics beat-to-beat changes of heart rate and blood pressure are encoded in symbol strings. Subsequently, the distribution properties of short symbol sequences (words) as well as the scaling properties of the whole symbol string are assessed. The comparison of joint symbolic heart rate and blood pressure dynamics in DCM (n = 75) with those in healthy controls (n = 75) showed significant changes. Both, the distribution of words and the scaling properties indicate a loss in heart rate dynamics associated with blood pressure regulation in DCM. In conclusion, the analyses of short- and long-term JSDs provide insights into complex physiological heart rate and blood pressure interactions and furthermore reveal patho-physiological cardiovascular control in DCM.     

Mobile IPv6 — Wegweiser in eine mobile Zukunft

Since mobile computing is getting more and more common, wireless technology is increasingly being used for Internet access and other IP-based communications. Some years ago, only a few people were using mobile phones to make telephone calls over GSM, whereas today you will hardly find anyone without his mobile companion in his pocket. In the future people will demand to get connected to the Internet by their IP-enabled smart-phones and PDAs always and anywhere. This article presents the upcoming Mobile IPv6 protocol, which will be the base for tomorrow’s worldwide IP-mobility. Mobile IPv6 will be widespread with the introduction of the Next-Generation Internet (IPv6).     

Modular Assembly of Red Blood Cell Superstructures from Metal–Organic Framework Nanoparticle-Based Building Blocks

Bio/artificial hybrid nanosystems based on biological matter and synthetic nanoparticles (NPs) remain a holy grail of materials science. Herein, inspired by the well-defined metal–organic framework (MOF) with diverse chemical diversities, the concept of “armored red blood cells” (armored RBCs) is introduced, which are native RBCs assembled within and protected by a functional exoskeleton of interlinked MOF NPs. Exoskeletons are generated within seconds through MOF NP interlocking based on metal-phenolic coordination and RBC membrane/NP complexation via hydrogen-bonding interactions at the cellular interface. Armored RBC formation is shown to be generalizable to many classes of MOF NPs or any NPs that can be coated by MOF. Moreover, it is found that armored RBCs preserve the original properties of RBCs (such as oxygen carrier capability and good ex ovo/in vivo circulation property) and show enhanced resistance against external stressors (like osmotic pressure, detergent, toxic NPs, and freezing conditions). By modifying the physicochemical properties of MOF NPs, armored RBCs provide the capability for blood nitric oxide sensing or multimodal imaging. The synthesis of armored RBCs is straightforward, reliable, and reversible and hence, represent a new class of hybrid biomaterials with a broad range of functionalities.