We present the very first worldwide ever-reported electrochemical biosensor based on a memristive effect and DNA aptamers. This novel device is developed to propose a completely new approach in ...cancer diagnostics. In this study, an affinity-based technique is presented for the detection of the prostate specific antigen (PSA) using DNA aptamers. The hysteretic properties of memristive silicon nanowires functionalized with these DNA aptamers provide a label-free and ultrasensitive biodetection technique. The ultrasensitive detection is hereby demonstrated for PSA with a limit of detection down to 23 aM, best ever published value for electrochemical biosensors in PSA detection. The effect of polyelectrolytes on our memristive devices is also reported to further show how positive or negative charges affect the memristive hysteresis. With such an approach, combining memristive nanowires and aptamers, memristive aptamer-based biosensors can be proposed to detect a wide range of cancer markers with unprecedent ultrasensitivities to also address the issue of an early detection of cancer.
•Wearable multi-sensing system for healthcare monitoring with nontoxic materials.•Integration of a flexible RE based on an ionic-liquid junction and of a cotton fluidics.•Integration with paper ...fluidics including a reservoir for already tested sweat.•Reversible and selective response in the physiological ranges with a wearable setup.•Proof-of-concept human trials for prototype's performance.
Despite the huge expansion in recent years of sweat sensing and wearable technologies, several challenges are still open, including poor sample collection, separate sampling and analysis, low multi-sensing capabilities and materials toxicity. In this work, we propose a novel wearable multi-electrode platform efficiently tackling some of these issues. The sensing technology is based on one-step electrodeposited platinum nanostructures to achieve reproducibility and biocompatibility. The platform is highly flexible and includes four electrodes for the simultaneous sensing of analytes, a temperature sensor and a stable reference electrode (RE) with an ionic-liquid junction. A low-cost cotton fluidics is designed to continuously bring fresh sweat to the sensing area, while disposing the already-tested sample. The excellent analytical performance of the proposed technology is proved for different applications: Li+ for Therapeutic Drug Monitoring (TDM) in psychiatric disorders, Pb2+ for the control of heavy metal contamination, K+ and Na+ for sport tracking. The sensors offer linear responses in artificial sweat in the ranges of clinical interest. A simulated wearable setup on a mannequin is used to test reversibility and selectivity. Finally, potassium and sodium are successfully tracked on five human volunteers during physical exercise. The accuracy of the in-situ measurements is demonstrated (Pearson coefficients of 0.97 and 0.81 for Na+ and K+, respectively). With its high biocompatibility, selectivity and accurate sample-handling, this wearable platform represents an important step towards the development of non-invasive monitoring devices for m-Health, paving the way for a better understanding of physiological parameters and clinical needs of each individual.
LUT-Based Hierarchical Reversible Logic Synthesis Soeken, Mathias; Roetteler, Martin; Wiebe, Nathan ...
IEEE transactions on computer-aided design of integrated circuits and systems,
2019-Sept., 2019-9-00, Letnik:
38, Številka:
9
Journal Article
Recenzirano
We present a synthesis framework to map logic networks into quantum circuits for quantum computing. The synthesis framework is based on lookup-table (LUT) networks, which play a key role in ...conventional logic synthesis. Establishing a connection between LUTs in an LUT network and reversible single-target gates in a reversible network allows us to bridge conventional logic synthesis with logic synthesis for quantum computing, despite several fundamental differences. We call our synthesis framework LUT-based hierarchical reversible logic synthesis (LHRS). Input to LHRS is a classical logic network representing an arbitrary Boolean combinational operation; output is a quantum network (realized in terms of Clifford+ T gates). The framework allows one to account for qubit count requirements imposed by the overlying quantum algorithm or target quantum computing hardware. In a fast first step, an initial network is derived that only consists of single-target gates and already completely determines the number of qubits in the final quantum network. Different methods are then used to map each single-target gate into Clifford+ T gates, while aiming at optimally using available resources. We demonstrate the versatility of our method by conducting a design space exploration using different parameters on a set of large combinational benchmarks. On the same benchmarks, we show that our approach can advance over the state-of-the-art hierarchical reversible logic synthesis algorithms.
This letter demonstrates the first fabricated four-transistor logic gates using polarity-configurable, gate-all-around silicon nanowire transistors. This technology enhances conventional CMOS ...functionality by adding the degree of freedom of dynamic polarity control n- or p-type. In addition, devices are fabricated with low, uniform doping profiles, reducing constraints at scaled technology nodes. We demonstrate through measurements and simulations how this technology can be applied to fabricate logic gates with fewer resources than CMOS. In particular, full-swing output XOR and NAND logic gates are demonstrated using the same physical four-transistor circuit.
We report on the electrochemical detection of anti-cancer drugs in human serum with sensitivity values in the range of 8-925 nA/μM. Multi-walled carbon nanotubes were functionalized with three ...different cytochrome P450 isoforms (CYP1A2, CYP2B6, and CYP3A4). A model used to effectively describe the cytochrome P450 deposition onto carbon nanotubes was confirmed by Monte Carlo simulations. Voltammetric measurements were performed in phosphate buffer saline (PBS) as well as in human serum, giving well-defined current responses upon addition of increasing concentrations of anti-cancer drugs. The results assert the capability to measure concentration of drugs in the pharmacological ranges in human serum. Another important result is the possibility to detect pairs of drugs present in the same sample, which is highly required in case of therapies with high side-effects risk and in anti-cancer pharmacological treatments based on mixtures of different drugs. Our technology holds potentials for inexpensive multi-panel drug-monitoring in personalized therapy.
In this paper, we propose a paradigm shift in representing and optimizing logic by using only majority (MAJ) and inversion (INV) functions as basic operations. We represent logic functions by ...majority-inverter graph (MIG): a directed acyclic graph consisting of three-input majority nodes and regular/complemented edges. We optimize MIGs via a new Boolean algebra, based exclusively on majority and inversion operations, that we formally axiomatize in this paper. As a complement to MIG algebraic optimization, we develop powerful Boolean methods exploiting global properties of MIGs, such as bit-error masking. MIG algebraic and Boolean methods together attain very high optimization quality. Considering the set of IWLS'05 benchmarks, our MIG optimizer (MIGhty) enables a 7% depth reduction in LUT-6 circuits mapped by ABC while also reducing size and power activity, with respect to similar and-inverter graph (AIG) optimization. Focusing on arithmetic intensive benchmarks instead, MIGhty enables a 16% depth reduction in LUT-6 circuits mapped by ABC, again with respect to similar AIG optimization. Employed as front-end to a delay-critical 22-nm application-specified integrated circuit flow (logic synthesis + physical design) MIGhty reduces the average delay/area/power by 13%/4%/3%, respectively, over 31 academic and industrial benchmarks. We also demonstrate delay/area/power improvements by 10%/10%/5% for a commercial FPGA flow.
Carbon nanotubes have been attracting a lot of interest as electron transfer mediators to enhance electrochemical biosensing. The main reason behind this is usually recognized in terms of augmented ...electrochemical active surface area. The aim of this paper is to review other phenomena that occur at the electrochemical interface. Three distinct features of these phenomena mainly appear in electrochemical biosensing. We introduce the Cottrell, Randle-Sevčick, and Nernst effects to address these features. By using these features, several electrochemical biosensing systems are investigated. Differences among the proposed systems are presented and analyzed in light of these effects. We finally have demonstrated that carbon nanotubes may induce completely opposite effects when dealing with different biosensing systems. This paper also shows that even seemingly small differences (e.g., changing metabolite as detected by the same enzyme) might result in opposite effects on the same carbon nanotube based sensor. Nevertheless, it is shown that carbon nanotubes, in some cases, confirm their exceptional nature in enhancing the sensor performance by orders of magnitude. The sensitivity increases from 87±62 to 3718±73nA/μM ×cm2 and detection limit decreases from 7.5±5.3mM to 84±2μM in case of cyclophosphamide detected by the cytochromes P450 3A4.
A multi-channel front-end for electrochemical sensing is presented. It consists of a multiplexed four-channel readout interface supporting amperometric, voltammetric, and potentiometric measurements. ...The electronic interface is co-designed according to the target biomarker specifications, and exhibits excellent linearity in both current and voltage sensing. The sensing front-end is characterized with lactate, paracetamol, and lithium sensing, yielding sensitivity of 1.2 ± 0.3μA/mM, 69.6 ± 2nA/μM, and 55.6mV/decade, respectively. These performances are comparable with the ones obtained with a bulky commercial Autolab potentiostat. Moreover, the limit of detection achieved are of 37±8 μM, 2.1± 1.22 μM, and 11± 3.5 μM, respectively, for the aforementioned sensors. These values are more than one order of magnitude lower than the relevant detection range. This successful characterization demonstrates the ability of the proposed system to monitor, in a broader sense, metabolites, drugs, and electrolytes. The programmability, versatility and portability of the front-end interface paves the way for a continuous monitoring of different families of biomarkers, suitable for advanced healthcare diagnosis and wearable physiology.
The evaluation of the efficacy of drugs’ action is of crucial importance for preventing adverse effects due to over‐ or under‐dosing. This is especially valuable in the case of propofol, a benchmark ...anesthetic, since its plasma concentration has to be continuously monitored to achieve and maintain a certain level of sedation during the surgery. To this end, long‐term monitoring approaches have to be implemented. Electrochemical sensors have taken great interest for propofol monitoring. However, the problem of fouling of the propofol on the sensing electrodes, as due to compound‐polymerization caused by successive measurements, makes almost impossible the long‐term drug monitoring of such a compound. For the first time by this study, we have shown that long‐term monitoring of propofol can be achieved by electrochemical sensors based on Pencil Graphite Electrode (PGE) with a proper clay/graphite ratio. Our research has shown that a clay/graphite ratio of 0.4 prevents fouling and hence enables monitoring of propofol.up to 4‐hours. Surface analysis of various PGEs has been conducted via Scanning Electron Microscopy (SEM) and Electrochemical Impedance Spectroscopy (EIS) whereas detection of propofol has been investigated by Cyclic Voltammetry (CV).
Exact synthesis is a versatile logic synthesis technique with applications to logic optimization, technology mapping, synthesis for emerging technologies, and cryptography. In recent years, advances ...in SAT solving have led to a heightened research effort into SAT-based exact synthesis. Advantages of exact synthesis include the use of various constraints (e.g., synthesis of emerging technology circuits). However, although progress has been made, its runtime remains unpredictable. This paper identifies two key points as hurdles to further progress. First, there are open questions regarding the design and implementation of exact synthesis systems, due to the many degrees of freedom. For example, there are different CNF encodings, different symmetry breaks to choose from, and different encodings may be suitable for different domains. Second, SAT-based exact synthesis is difficult to parallelize. Indeed, this is a common drawback of logic synthesis algorithms. This paper proposes four ways to close some open questions and to reduce runtime: 1) quantifying differences between CNF encoding schemes and their impacts on runtime; 2) demonstrating impact of symmetry breaking constraints; 3) showing how directed acyclic graph topology information can be used to decrease runtime; and 4) showing how topology information can be used to leverage parallelism.
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