Activiteit

Further investigation is required into the source of the reported systematic trends dependent on field-size and depth of measurement.Volatile organic compounds (VOC) detected in human breath, urine, stool, sweat, saliva, and blood result from metabolic processes in the body during health or disease. Using sophisticated measurement systems, small amounts of these compounds can be detected in the above bodily fluids. Multiple studies in adults and children have shown the potential of these compounds to differentiate between healthy individuals and patients by detecting profiles of compounds in non-invasively collected samples. However, the detection of biomarkers in VOCs from neonates is particularly attractive due to the non-invasive nature of its approach, and its ability to track disease progress by longitudinal sampling. In this work we have reviewed the literature on the use of VOCs in neonates and identified areas for future work.Objective.Advances in brain-machine interfaces (BMIs) are expected to support patients with movement disorders. Electrocorticogram (ECoG) measures electrophysiological activities over a large area using a low-invasive flexible sheet placed on the cortex. ECoG has been considered as a feasible signal source of the clinical BMI device. To capture neural activities more precisely, the feasibility of higher-density arrays has been investigated. However, currently, the number of electrodes is limited to approximately 300 due to wiring difficulties, device size, and system costs.Approach.We developed a high-density recording system with a large coverage (14 × 7 mm2) and using 1152 electrodes by directly integrating dedicated flexible arrays with the neural-recording application-specific integrated circuits and their interposers.Main results.Comparative experiments with a 128-channel array demonstrated that the proposed device could delineate the entire digit representation of a nonhuman primate. Subsampling analysis revealed that higher-amplitude signals can be measured using higher-density arrays.Significance.We expect that the proposed system that simultaneously establishes large-scale sampling, high temporal-precision of electrophysiology, and high spatial resolution comparable to optical imaging will be suitable for next-generation brain-sensing technology.The variational wave functions based on neural networks have recently started to be recognized as a powerful ansatz to represent quantum many-body states accurately. In order to show the usefulness of the method among all available numerical methods, it is imperative to investigate the performance in challenging many-body problems for which the exact solutions are not available. Here, we construct a variational wave function with one of the simplest neural networks, the restricted Boltzmann machine (RBM), and apply it to a fundamental but unsolved quantum spin Hamiltonian, the two-dimensionalJ1-J2Heisenberg model on the square lattice. We supplement the RBM wave function with quantum-number projections, which restores the symmetry of the wave function and makes it possible to calculate excited states. Then, we perform a systematic investigation of the performance of the RBM. We show that, with the help of the symmetry, the RBM wave function achieves state-of-the-art accuracy both in ground-state and excited-state calculations. The study shows a practical guideline on how we achieve accuracy in a controlled manner.Mammal whiskers can perceive obstacles and airflows. In this study, an electronic whisker (E-whisker) sensor was designed and fabricated by setting a PVDF ring with symmetrical electrodes on the root of a fiber beam. The vibration displacements with different waveforms were applied at the free end of the E-whisker beam to study the relationship between the vibration displacements and the output signals. learn more The E-Whisker sense ability for protrusions was investigated by driving it to sweep through the surface of a base platform. Then a static E-whisker beam and a swinging E-whisker were separately placed in a wind tunnel to detect the airflow perception of the sensor. The experimental results suggested that the E-whisker could sense the frequencies and amplitudes of displacements at its free end, the height and width of a platform or the heights of other irregular protrusions; the static E-whisker could sense the magnitude or direction of an impact airflow while the swinging E-whisker could sense the magnitude of a constant airflow. Thus, this kind of E-whisker could perceive the environment and airflow through touch sensation and could be used as a physical model to study the principles and abilities of animal whiskers to perceive obstacles and airflows.Directed self-assembly of nanoparticles (NPs) is a promising strategy for bottom-up fabrication of nanostructured materials with tailored composition and morphology. Here, we present a simple and highly flexible method where charged magnetic aerosolized (i.e. suspended in a gas) NPs with tunable size and composition are self-assembled into nanostructures using combined electric and magnetic fields. Size-selected Co, Ni, and Fe NPs have been generated by spark ablation, and self-assembled into different structures, ranging from one-dimensional nanochains to macroscopic three-dimensional networks. By comparing the resulting structures with simulations, we can conclude that the magnetization of the NPs governs the self-assembly through interparticle magnetic dipole-dipole interactions. We also show how the orientation of the external magnetic field directs the self-assembly into differently aligned nano- and macroscopic structures. These results demonstrate how aerosol deposition in a combined electric and magnetic field can be used for directed bottom-up self-assembly of nanostructures with specialized composition and morphology.

Lumbar spinal stenosis (LSS) is a common and debilitating condition that is increasing in prevalence in the world population. Surgical decompression is often standard treatment when conservative measures have failed. Interspinous distractor devices (IDDs) have been proposed as a safe alternative; however, the associated cost and early reports of high failure rates have brought their use into question. The primary objective of this study was to determine the cost-effectiveness and long-term quality-of-life (QOL) outcomes after treatment of LSS with the X-Stop IDD compared with surgical decompression by laminectomy.

A multicenter, open-label randomized controlled trial of 47 patients with LSS was conducted; 21 patients underwent insertion of the X-Stop device and 26 underwent laminectomy. The primary outcomes were monetary cost and QOL measured using the EQ-5D questionnaire administered at 6-, 12-, and 24-month time points.

The mean monetary cost for the laminectomy group was £2712 ($3316 [USD]), and the mean cost for the X-Stop group was £5148 ($6295) £1799 ($2199) procedural cost plus £3349 mean device cost (£2605 additional cost per device).