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Digital computing is nearing its physical limits as computing needs and energy consumption rapidly increase. Analogue-memory-based neuromorphic computing can be orders of magnitude more energy efficient at data-intensive tasks like deep neural networks, but has been limited by the inaccurate and unpredictable switching of analogue resistive memory. Filamentary resistive random access memory (RRAM) suffers from stochastic switching due to the random kinetic motion of discrete defects in the nanometer-sized filament. In this work, this stochasticity is overcome by incorporating a solid electrolyte interlayer, in this case, yttria-stabilized zirconia (YSZ), toward eliminating filaments. Filament-free, bulk-RRAM cells instead store analogue states using the bulk point defect concentration, yielding predictable switching because the statistical ensemble behavior of oxygen vacancy defects is deterministic even when individual defects are stochastic. Both experiments and modeling show bulk-RRAM devices using TiO 2- X switching layers and YSZ electrolytes yield deterministic and linear analogue switching for efficient inference and training. Bulk-RRAM solves many outstanding issues with memristor unpredictability that have inhibited commercialization, and can, therefore, enable unprecedented new applications for energy-efficient neuromorphic computing. Beyond RRAM, this work shows how harnessing bulk point defects in ionic materials can be used to engineer deterministic nanoelectronic materials and devices., (© 2020 Wiley-VCH GmbH.)

The Oxford MinION, the first commercial nanopore sequencer, is also the first to implement molecule-by-molecule real-time selective sequencing or "Read Until". As DNA transits a MinION nanopore, real-time pore current data can be accessed and analyzed to provide active feedback to that pore. Fragments of interest are sequenced by default, while DNA deemed non-informative is rejected by reversing the pore bias to eject the strand, providing a novel means of background depletion and/or target enrichment. In contrast to the previously published pattern-matching Read Until approach, our RUBRIC method is the first example of real-time selective sequencing where on-line basecalling enables alignment against conventional nucleic acid references to provide the basis for sequence/reject decisions. We evaluate RUBRIC performance across a range of optimizable parameters, apply it to mixed human/bacteria and CRISPR/Cas9-cut samples, and present a generalized model for estimating real-time selection performance as a function of sample composition and computing configuration.

In ultralow Pu analyses, the gold standard is thermal ionization mass spectrometry (TIMS), which requires pure sources to achieve its performance. This purity is achieved through step-wise purifications. In this work single, anion-exchange beads were trapped in the tubing to allow for dynamic solution cycling over the surface of the beads to improve the rates of metal complex uptake. Rates of Pu sorption on single ∼900 μm SIR-1200 and ∼620 μm Reillex-HPQ beads were determined for single beads trapped in a tube with syringe pump driven dynamic solution cycling over the bead, improving sorption and desorption rates. A static control was used as a comparison. Using 238 Pu to enable facile activity-based measurements, rates were determined by measuring the residual Pu after contact with beads using liquid scintillation analysis (LSA) for fixed periods of time. Syringe pump driven dynamic solution cycling results in ∼5 and ∼15-fold improvements in the sorption rates for SIR-1200 and Reillex-HPQ. Impacts on desorption were also examined., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Emerging sequencing technologies are allowing us to characterize environmental, clinical and laboratory samples with increasing speed and detail, including real-time analysis and interpretation of data. One example of this is being able to rapidly and accurately detect a wide range of pathogenic organisms, both in the clinic and the field. Genomes can have radically different GC content however, such that accurate sequence analysis can be challenging depending upon the technology used. Here, we have characterized the performance of the Oxford MinION nanopore sequencer for detection and evaluation of organisms with a range of genomic nucleotide bias. We have diagnosed the quality of base-calling across individual reads and discovered that the position within the read affects base-calling and quality scores. Finally, we have evaluated the performance of the current state-of-the-art neural network-based MinION basecaller, characterizing its behavior with respect to systemic errors as well as context- and sequence-specific errors. Overall, we present a detailed characterization the capabilities of the MinION in terms of generating high-accuracy sequence data from genomes with a wide range of nucleotide content. This study provides a framework for designing the appropriate experiments that are the likely to lead to accurate and rapid field-forward diagnostics.

Advances in molecular biology, microfluidics, and laboratory automation continue to expand the accessibility and applicability of these methods beyond the confines of conventional, centralized laboratory facilities and into point of use roles in clinical, military, forensic, and field-deployed applications. As a result, there is a growing need to adapt the unit operations of molecular biology (e.g., aliquoting, centrifuging, mixing, and thermal cycling) to compact, portable, low-power, and automation-ready formats. Here we present one such adaptation, the rotary zone thermal cycler (RZTC), a novel wheel-based device capable of cycling up to four different fixed-temperature blocks into contact with a stationary 4-microliter capillary-bound sample to realize 1-3 second transitions with steady state heater power of less than 10 W. We demonstrate the utility of the RZTC for DNA amplification as part of a highly integrated rotary zone PCR (rzPCR) system that uses low-volume valves and syringe-based fluid handling to automate sample loading and unloading, thermal cycling, and between-run cleaning functionalities in a compact, modular form factor. In addition to characterizing the performance of the RZTC and the efficacy of different online cleaning protocols, we present preliminary results for rapid single-plex PCR, multiplex short tandem repeat (STR) amplification, and second strand cDNA synthesis.

Next-generation sequencing (NGS) is emerging as a powerful tool for elucidating genetic information for a wide range of applications. Unfortunately, the surging popularity of NGS has not yet been accompanied by an improvement in automated techniques for preparing formatted sequencing libraries. To address this challenge, we have developed a prototype microfluidic system for preparing sequencer-ready DNA libraries for analysis by Illumina sequencing. Our system combines droplet-based digital microfluidic (DMF) sample handling with peripheral modules to create a fully-integrated, sample-in library-out platform. In this report, we use our automated system to prepare NGS libraries from samples of human and bacterial genomic DNA. E. coli libraries prepared on-device from 5 ng of total DNA yielded excellent sequence coverage over the entire bacterial genome, with >99% alignment to the reference genome, even genome coverage, and good quality scores. Furthermore, we produced a de novo assembly on a previously unsequenced multi-drug resistant Klebsiella pneumoniae strain BAA-2146 (KpnNDM). The new method described here is fast, robust, scalable, and automated. Our device for library preparation will assist in the integration of NGS technology into a wide variety of laboratories, including small research laboratories and clinical laboratories.

We have developed an automated quality control (QC) platform for next-generation sequencing (NGS) library characterization by integrating a droplet-based digital microfluidic (DMF) system with a capillary-based reagent delivery unit and a quantitative CE module. Using an in-plane capillary-DMF interface, a prepared sample droplet was actuated into position between the ground electrode and the inlet of the separation capillary to complete the circuit for an electrokinetic injection. Using a DNA ladder as an internal standard, the CE module with a compact LIF detector was capable of detecting dsDNA in the range of 5-100 pg/μL, suitable for the amount of DNA required by the Illumina Genome Analyzer sequencing platform. This DMF-CE platform consumes tenfold less sample volume than the current Agilent BioAnalyzer QC technique, preserving precious sample while providing necessary sensitivity and accuracy for optimal sequencing performance. The ability of this microfluidic system to validate NGS library preparation was demonstrated by examining the effects of limited-cycle PCR amplification on the size distribution and the yield of Illumina-compatible libraries, demonstrating that as few as ten cycles of PCR bias the size distribution of the library toward undesirable larger fragments., (© 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Digital microfluidics (DMF) has recently emerged as a popular technology for a wide range of applications. In DMF, nanoliter to microliter droplets containing samples and reagents can be manipulated to carry out a range of discrete fluidic operations simply by applying a series of electrical potentials to an array of patterned electrodes coated with a hydrophobic insulator. DMF is distinct from microchannel-based fluidics as it allows for precise control over multiple reagent phases (liquids and solids) in heterogeneous systems with no need for complex networks of connections, microvalves, or pumps. In this review, we discuss the most recent developments in this technology with particular attention to the potential benefits and outstanding challenges for applications in chemistry, biology, and medicine.

Next-generation sequencing (NGS) technology is a promising tool for identifying and characterizing unknown pathogens, but its usefulness in time-critical biodefense and public health applications is currently limited by the lack of fast, efficient, and reliable automated DNA sample preparation methods. To address this limitation, we are developing a digital microfluidic (DMF) platform to function as a fluid distribution hub, enabling the integration of multiple subsystem modules into an automated NGS library sample preparation system. A novel capillary interface enables highly repeatable transfer of liquid between the DMF device and the external fluidic modules, allowing both continuous-flow and droplet-based sample manipulations to be performed in one integrated system. Here, we highlight the utility of the DMF hub platform and capillary interface for automating two key operations in the NGS sample preparation workflow. Using an in-line contactless conductivity detector in conjunction with the capillary interface, we demonstrate closed-loop automated fraction collection of target analytes from a continuous-flow sample stream into droplets on the DMF device. Buffer exchange and sample cleanup, the most repeated steps in NGS library preparation, are also demonstrated on the DMF platform using a magnetic bead assay and achieving an average DNA recovery efficiency of 80%±4.8%., (Copyright © 2011 Society for Laboratory Automation and Screening. Published by Elsevier Inc. All rights reserved.)

Introduction: Bite wounds of the oral mucosa heal after eliminating the causative irritant, but there are serious exceptions from the rule. We present the case of a 37-year-old woman with an ulcer of the mucosa of the lower lip, which had been present for 10 days, and leucopenia., Discussion: Agranulocytosis after the use of metamizole is part from leukaemia and lues, a rare reason for non-healing ulcers of the mucosa of the oral cavity without fulminant signs for inflammation., Conclusion: As this is a life-threatening disease, medical therapy must begin immediately.

Selective reduction of bone without collateral damage (nerves, teeth) is essential in apicectomy. To test whether skills acquired on a virtual apicectomy simulator (VOXEL-MAN system with integrated force-feedback) are transferable from virtual to physical reality, two groups of trainees were compared. Group 1 received computer-based virtual surgical training before performing an apicectomy in a pig cadaver model. The probability of preserving vital neighboring structures was improved significantly, i.e. six-fold, after virtual surgical training (P<0.001). The average volume of the bony defects created by the trainees of Group 2 (mean: 0.47 ml) was significantly (P<0.001) larger than by the trainees of Group 1 (mean: 0.25 ml). Most importantly, the ability to objectively self-assess performance was significantly improved after virtual training. Training with a virtual apicectomy simulator appears to be effective, and the skills acquired are transferable to physical reality.

Background: Occasionally, trivial odontogenic infections may develop into complex diseases. This may even result in an unrestrained phlegmonous spread causing life-threatening complications. These problems have decreased since the introduction of antibiotics and also due to improved oral hygiene and improved diagnostic measures resulting in optimized medical treatment. However, life-threatening forms are still seen, in particular if infections spread along the cervical fascial sheaths down towards to the mediastinum. Over the past decade the number of critical infections has increased in other medical specialties. This is usually explained by the development of multiresistant pathogens in the context of nosocomial infections., Patients and Methods: We reviewed the patients' records of the past 15 years at the Department of Oral and Maxillofacial Surgery of the University Hospital Kiel to assess a possible increase of odontogenic infections with life-threatening complications. From 1990 to 2004, four patients with odontogenic infections exhibiting critical phlegmonous spread were treated in the intensive care unit. Two patients developed bacterial mediastinitis which could be controlled by intravenous antibiotics only. One patient progressed to general septic mediastinitis and eventually died of cardiorespiratory arrest. The last patient also had septic mediastinitis and developed right pleural empyema. Several operations were necessary before the disease could be controlled. This patient's case report is presented in detail., Conclusion: The prognosis of patients with mediastinitis crucially depends on (a) early diagnosis including computed tomography of the neck and thorax, (b) early radical surgical intervention, and (c) optimized pathogen-oriented antibiotic treatment.