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There is a notable correlation between Eurosceptic and populist political actors, discourses and agendas across Europe. Since 2015, the ongoing conflict between Poland and the European Commission concerning the rule of law has brought European integration to the centre of Polish politics. The main focus of this article is on the relationship and interaction between populism and Euroscepticism, as analysed through the example of Polish political parties. To this end, the article investigates the different forms of EU contestation by Polish populist right-wing parties and assesses the extent to which these are expressed through populist discourse. We find a strong correlation between populist and Eurosceptic attitudes of Polish political parties. With the growing number of populist parties entering the mainstream and 'uncivil society' actors transforming into political parties, the anti-elitist discourse generates a need to locate the 'corrupted elites' outside of the national power structures. [ABSTRACT FROM AUTHOR]

Light‐emitting complex defects in silicon have been considered a potential platform for quantum technologies based on spin and photon degrees of freedom working at telecom wavelengths. Their integration in complex devices is still in its infancy and has been mostly focused on light extraction and guiding. Here the control of the electronic states of carbon‐related impurities (G‐centers) is addressed via strain engineering. By embedding them in patches of silicon on insulator and topping them with SiN, symmetry breaking along [001] and [110] directions is demonstrated, resulting in a controlled splitting of the zero phonon line (ZPL), as accounted for by the piezospectroscopic theoretical framework. The splitting can be as large as 18 meV, and it is finely tuned by selecting patch size or by moving in different positions on the patch. Some of the split, strained ZPLs are almost fully polarized, and their overall intensity is enhanced up to 7 times with respect to the flat areas, whereas their recombination dynamics is slightly affected accounting for the lack of Purcell effect. This technique can be extended to other impurities and Si‐based devices such as suspended bridges, photonic crystal microcavities, Mie resonators, and integrated photonic circuits. [ABSTRACT FROM AUTHOR]

Here, we investigate the magnetic field dependent photoluminescence (PL) of a fiber-coupled diamond single crystal with a high density of nitrogen vacancy (NV) centers. Angle-dependent magnetic field sweep measurements between 0 and 111 mT were performed using an oscillating illumination combined with lock-in techniques. Besides the expected superposed PL of differently oriented NV centers, a zoo of features in the PL are found. These features can be associated with level anti-crossings and cross relaxations. In particular, PL measurements allowed us to detect auto-cross relaxation between coupled NV centers. Moreover, the PL measurements at low magnetic fields show dips suggesting an interaction of NV centers with additional spin defects. The results presented here are not only a study for NV-based fiber-coupled sensors made of diamond, but also show a way to investigate with manageable effort and purely an optical multispin interaction with at least one NV center as a constituent. [ABSTRACT FROM AUTHOR]

Nuclear magnetic resonance techniques are widely used in the natural sciences but they lack sensitivity. Therefore, large sample volumes or long measurement times are necessary. In this work, we investigate the polarization of bulk 13 C nuclei in a diamond above the thermal equilibrium at room temperature. Previously studied mechanisms utilize direct coupling to nitrogen vacancy centers or the additional assistance of substitutional nitrogen impurities for this purpose. We exploit strongly coupled nitrogen vacancy centers as polarization sources. We study two approaches to transfer the optically induced polarization of the electron spins of the nitrogen vacancy centers to nearby nuclear spins. First, the electron-nuclear polarization transfer is achieved by energy matching conditions or, second, by magnetic field sweeps inducing Landau–Zener-like transitions. Simulations according to a quantum mechanical system consisting of two coupled nitrogen vacancy centers and a weakly coupled 13 C spin show an excellent agreement with the experimental data. Both approaches allow a reduction of the measurement time by roughly three orders of magnitude. [ABSTRACT FROM AUTHOR]

The application of transparent conducting oxides in electronic devices like solar cells or displays is common. By transferring this technology to quantum sensing and computing in the form of microwave conductors, it is possible to benefit from the advantages of these materials. By using indium tin oxide (ITO), it is demonstrated that at an arbitrary position below the conductor, an arbitrary elliptical microwave polarization can be produced by two independent sources. This is independent of the geometry and size of the ITO, whereby a non-resonant microwave approach can be chosen. Using single nitrogen vacancy (NV) centers in diamond in combination with a cross-like ITO structure, each NV center can be addressed with an ideal (clockwise or anticlockwise) microwave polarization. By optimizing the coupling of the microwave field to the NV centers and minimizing the conductor size, the creation of smaller devices compared to common approaches is possible. [ABSTRACT FROM AUTHOR]

In this work, we demonstrate the feasibility of detecting low energy single ions using nanometer-thick and few-micrometer-wide graphite flakes at room temperature. We used electrically contacted samples of highly oriented pyrolytic graphite and measured in situ the change in electrical resistance upon ion irradiation using a self-made nanovoltmeter. Eight samples of different dimensions were prepared and subjected to ion irradiation from various species. A fluence as low as 5 × 10 8 cm − 2 corresponding to a few hundreds of ions irradiated was sufficient to produce a signal significantly above the noise level. Furthermore, we used a model to describe the dependence of the change in electrical resistance on the defect concentration induced by ion irradiation. By extrapolating this model to the level of single ions, our findings support the feasibility of detecting single ions at room temperature using thin graphite as a detector material. [ABSTRACT FROM AUTHOR]

The authors report on the characterization at the single‐defect level of germanium‐vacancy (GeV) centers in diamond produced upon Ge− ion implantation and different subsequent annealing processes, with a specific focus on the effect of high‐pressure‐high‐temperature (HPHT) processing on their quantum‐optical properties. Different post‐implantation annealing conditions are explored for the optimal activation of GeV centers, namely, 900 °C 2 h, 1000 °C 10 h, 1500 °C 1 h under high vacuum, and 2000 °C 15 min at 6 GPa pressure. A systematic analysis of the relevant emission properties, including the emission intensity in saturation regime and the excited state radiative lifetime, is performed on the basis of a set of ion‐implanted samples, with the scope of identifying the most suitable conditions for the creation of GeV centers with optimal quantum‐optical emission properties. The main performance parameter adopted here to describe the excitation efficiency of GeV centers as single‐photon emitters is the ratio between the saturation optical excitation power and the emission intensity at saturation. The results show an up to eightfold emission efficiency increase in HPHT‐treated samples with respect to conventional annealing in vacuum conditions, suggesting a suitable thermodynamic pathway toward the repeatable fabrication of ultra‐bright GeV centers for single‐photon generation purposes. [ABSTRACT FROM AUTHOR]

Quantum sensors using solid state qubits have demonstrated outstanding sensitivity, beyond that possible using classical devices. In particular, those based on colour centres in diamond have demonstrated high sensitivity to magnetic field through exploiting the field-dependent emission of fluorescence under coherent control using microwaves. Given the highly biocompatible nature of diamond, sensing from biological samples is a key interdisciplinary application. In particular, the microscopic-scale study of living systems can be possible through recording of temperature and biomagnetic field. In this work, we use such a quantum sensor to demonstrate such microscopic-scale recording of electrical activity from neurons in fragile living brain tissue. By recording weak magnetic field induced by ionic currents in mouse corpus callosum axons, we accurately recover signals from neuronal action potential propagation while demonstrating in situ pharmacology. Our sensor allows recording of the electrical activity in neural circuits, disruption of which can shed light on the mechanisms of disease emergence. Unlike existing techniques for recording activity, which can require potentially damaging direct interaction, our sensing is entirely passive and remote from the sample. Our results open a promising new avenue for the microscopic recording of neuronal signals, offering the eventual prospect of microscopic imaging of electrical activity in the living mammalian brain. [ABSTRACT FROM AUTHOR]

An integrated magnetic sensor is designed and tested that utilizes the negatively charged nitrogen vacancy centers (NVC) in diamond as a magnetic field‐sensitive quantum material, which is accessed and readout solely optically. The compact sensor device features a side length of 10 mm and includes a small HPHT diamond slab, light‐emitting diode (LED) for excitation, and integrated photodiodes. A microwave‐free approach is used. With the device, DC sensitivity to magnetic fields of 49 nA mT−1 in the range of 5–50 mT is achieved. The sensor device is also capable of detecting very small magnetic fields: Magnetic field dependencies at very low flux densities in the μT range (zero‐magnetic field) show a characteristic fluorescence behavior revealing a sensitivity of 4.8 pA μT−1. Additionally, a ray‐tracing model is applied, to identify loss mechanisms in the setup. Using this device, an ultracompact, reliable, and industry‐ready package is made available for sensor developments in industry and academia. [ABSTRACT FROM AUTHOR]

The detection of physiological activity at the microscopic level is key for understanding the function of biosystems and relating this to their physical structure. Current sensing methods for in vitro study of living tissue often rely on invasive probes to stimulate and detect activity, bearing the risk of inducing damage in the target system. In recent years, a new type of quantum sensor based on color centers in diamond has begun to offer the possibility to instead passively sense and image living biological systems. Here, we use such a sensor to realize the recording of the biomagnetic field generated by tightly focused, high intensity pulsed laser optogenetic neuromuscular stimulation of extensor digitorum longus muscles, dissected from mice and kept alive in carbogenated solution. Recordings captured a compound action potential response and a slow signal component, which we seek to explain using a detailed model of the biological system. We show proof-of-principle experimental recording of localized neuromuscular activity from the laser stimulation site without photovoltaic or fluorescence artifacts associated with alternative techniques. Our work represents a further step toward passive sensing and imaging at the microscopic level with quantum sensing, enabling further research into mapping of neural activity and intracellular processes. [ABSTRACT FROM AUTHOR]

Silicon‐based micro‐ and nano‐structures for light management at near‐infrared and visible frequencies have been widely exploited for guided optics and metasurfaces. However, light emission with this material has been hampered by the indirect character of its bandgap. Here it is shown that, via ion beam implantation, light emitting G‐centers can be directly embedded within Si‐based Mie resonators previously obtained by solid state dewetting. Size‐ and position‐dependent, directional light emission at 120 K is demonstrated experimentally and confirmed by finite difference time domain simulations. It is estimated that, with an optimal coupling of the G‐centers emission with the resonant antennas, a collection efficiency of about 90% can be reached using a conventional objective lens. The integration of these telecom‐frequency emitters in resonant antennas is relevant for their efficient exploitation in quantum optics applications and more generally to Si‐based photonic metasurfaces. [ABSTRACT FROM AUTHOR]

We report the fabrication of isolated G centers in silicon with single photon emission at optical telecommunication wavelengths. Our sample is made from a silicon-on-insulator wafer, which is locally implanted with carbon ions and protons at various fluences. Decreasing the implantation fluences enables us to gradually switch from large ensembles to isolated single defects, reaching areal densities of G centers down to ∼0.2 μm−2. Single defect creation is demonstrated by photon antibunching in intensity-correlation experiments, thus establishing our approach as an effective procedure for generating single artificial atoms in silicon for future quantum technologies. [ABSTRACT FROM AUTHOR]

Meanders formed where the Antarctic Circumpolar Current (ACC) interacts with topography have been identified as dynamical hot spots, characterized by enhanced eddy energy, momentum transfer, and cross-front exchange. However, few studies have used observations to diagnose the dynamics of ACC standing meanders. We use a synoptic hydrographic survey and satellite altimetry to explore the momentum and vorticity balance of a Subantarctic Front standing meander, downstream of the Southeast Indian Ridge. Along-stream anomalies of temperature in the upper ocean (150–600 m) show along-stream cooling entering the surface trough and along-stream warming entering the surface crest, while warming is observed from trough to crest in the deeper ocean (600–1500 m). Advection of relative vorticity is balanced by vortex stretching, as found in model studies of meandering currents. Meander curvature is sufficiently large that the flow is in gradient wind balance, resulting in ageostrophic horizontal divergence. This drives downwelling of cooler water along isopycnals entering the surface trough and upwelling of warmer water entering the surface crest, consistent with the observed evolution of temperature anomalies in the upper ocean. Progressive along-stream warming observed between 600 and 1500 m likely reflects cyclogenesis in the deep ocean. Vortex stretching couples the upper and lower water column, producing a low pressure at depth between surface trough and crest and cyclonic flow that carries cold water equatorward in the surface trough and warm water poleward in the surface crest (poleward heat flux). The results highlight gradient–wind balance and cyclogenesis as central to dynamics of standing meanders and their critical role in the ACC momentum and vorticity balance. Significance Statement: The Antarctic Circumpolar Current (ACC) in the Southern Ocean is a nearly zonal current that encircles Antarctica. It acts as a barrier between warmer water equatorward and colder water poleward. In a few regions where the current encounters strong topographic changes, the current meanders and opens a pathway for heat to travel across the ACC toward Antarctica. We surveyed a meander in the ACC and examined the along-stream change of temperature. In the upper ocean, temperature changes are caused by a vertical circulation, bringing cool water down when entering the surface trough (the part of the meander closest to the equator), and warm water up when exiting the surface trough and entering the surface crest. At depth, cold water is transported equatorward in the surface trough and warm water poleward in the surface crest, leading to a net transport of heat poleward. This study highlights the importance of the secondary circulation within a meander for generating cross-ACC flows and moving heat toward Antarctica. [ABSTRACT FROM AUTHOR]

Background: An important focus of post-stroke physical therapy is to improve walking and walking capacity. However, many people after stroke experience difficulties with gait-related participation, which includes more than walking capacity alone. Gait-related participation involves walking with a participation goal and requires to deal with changes in the environment during walking and perform dual tasks, for example. Objective: To explore barriers and facilitators for gait-related participation from the perspective of people after stroke. This knowledge can contribute to the development of effective interventions to improve gait-related participation. Methods: Semi-structured interviews were conducted to investigate how people after stroke experience gait-related participation. Audio-recorded interviews were transcribed, anonymized, and analyzed thematically. Barriers and facilitators were categorized according to the International Classification of Functioning, Disability and Health (ICF) framework. Results: Twenty-one people after stroke participated. Median age was 65 years, median time since stroke 16 weeks. Barriers were reported in movement-related functions, cognitive functions, mobility, personal factors, and environmental factors. Facilitators were found on participation level and in personal and environmental factors, such as motivation and family support. Conclusion: People after stroke who were physically able to walk independently still described multiple barriers to gait-related participation in all components of the ICF framework. [ABSTRACT FROM AUTHOR]

Several diamond bulk crystals with a concentration of electrically neutral single substitutional nitrogen atoms of ≲80 ppm, the so‐called C or P1 centers, are irradiated with electrons at 10 MeV energy and low fluence. The results show a complete suppression of the irreversible behavior in field and temperature of the magnetization below 30 K, after a decrease in ≲40 ppm in the concentration of C centers produced by the electron irradiation. This result indicates that magnetic C centers are at the origin of the large hysteretic behavior found recently in nitrogen‐doped diamond crystals. This is remarkable because of the relatively low density of C centers, stressing the extraordinary role of the C centers in triggering those phenomena in diamond at relatively high temperatures. After annealing the samples at high temperatures in vacuum, the hysteretic behavior is partially recovered. [ABSTRACT FROM AUTHOR]

An efficient atom–photon interface is a key requirement for the integration of solid-state emitters, such as color centers in diamond, into quantum technology applications. As other solid-state emitters, however, their emission into free space is severely limited due to the high refractive index of the bulk host crystal. In this work, we present a planar optical antenna based on two silver mirrors coated on a thin single crystal diamond membrane, forming a planar Fabry–Pérot cavity that improves the photon extraction from single tin vacancy (SnV) centers and their coupling to an excitation laser. Upon numerical optimization of the structure, we find theoretical enhancements in the collectible photon rate by a factor of 60 as compared to the bulk case. As a proof-of-principle demonstration, we fabricate single crystal diamond membranes with sub-μm thickness and create SnV centers by ion implantation. Employing off-resonant excitation, we show a sixfold enhancement of the collectible photon rate, yielding up to half a million photons per second from a single SnV center. At the same time, we observe a significant reduction of the required excitation power in accordance with theory, demonstrating the functionality of the cavity as an optical antenna. Due to its planar design, the antenna simultaneously provides similar enhancements for a large number of emitters inside the membrane. Furthermore, the monolithic structure provides high mechanical stability and straightforwardly enables operation under cryogenic conditions as required in most spin–photon interface implementations. [ABSTRACT FROM AUTHOR]

We report on the systematic characterization of the optical properties of diamond color centers based on Pb impurities. An ensemble photoluminescence analysis of their spectral emission was performed at different excitation wavelengths in the 405–520 nm range and at different temperatures in the 4–300 K range. The series of observed spectral features consist of different emission lines associated with Pb-related defects. Finally, a room-temperature investigation of single-photon emitters under 490.5 nm laser excitation is reported, revealing different spectral signatures with respect to those already reported under 514 nm excitation. This work represents a substantial progress with respect to previous studies on Pb-related color centers, both in the attribution of an articulated series of spectral features and in the understanding of the formation process of this type of defect, thus clarifying the potential of this system for high-impact applications in quantum technologies. [ABSTRACT FROM AUTHOR]

Objective After stroke, people experience difficulties with walking that lead to restrictions in participation in daily life. The purpose of this study was to examine the effect of virtual reality gait training (VRT) compared to non–virtual reality gait training (non-VRT) on participation in community-living people after stroke. Methods In this assessor-blinded, randomized controlled trial with 2 parallel groups, people were included between 2 weeks and 6 months after stroke and randomly assigned to the VRT group or non-VRT group. Participants assigned to the VRT group received training on the Gait Real-time Analysis Interactive Lab (GRAIL), and participants assigned to the non-VRT group received treadmill training and functional gait exercises without virtual reality. Both training interventions consisted of 12 30-minute sessions during 6 weeks. The primary outcome was participation measured with the restrictions subscale of the Utrecht Scale for Evaluation of Rehabilitation-Participation (USER-P) 3 months postintervention. Secondary outcomes included subjective physical functioning, functional mobility, walking ability, dynamic balance, walking activity, fatigue, anxiety and depression, falls efficacy, and quality of life. Results Twenty-eight participants were randomly assigned to the VRT group and 27 to the non-VRT group, of whom 25 and 22 attended 75% or more of the training sessions, respectively. No significant differences between the groups were found over time for the USER-P restrictions subscale (1.23; 95% CI = −0.76 to 3.23) or secondary outcome measures. Patients' experiences with VRT were positive, and no serious adverse events were related to the interventions. Conclusions The effect of VRT was not statistically different from non-VRT in improving participation in community-living people after stroke. Impact Although outcomes were not statistically different, treadmill-based VRT was a safe and well-tolerated intervention that was positively rated by people after stroke. VR training might, therefore, be a valuable addition to stroke rehabilitation. Lay Summary VRT is feasible and was positively experienced by people after stroke. However, VRT was not more effective than non-VRT for improving walking ability and participation after stroke. [ABSTRACT FROM AUTHOR]

Artificial atoms like the nitrogen vacancy (NV) centers in diamond enable the realization of fully functional qubits in a solid at room temperature. The functionalities of all the parts needed to create a quantum computer, such as quantum error correction, couplings, quantum teleportation, and a quantum repeater, have already been experimentally demonstrated. These achievements are expected to influence the industrial development of quantum information technology as well as quantum sensing. Whereas quantum sensing has been established and a large number of organizations are working on new developments in this area, a quantum computer itself remains elusive due to technical reasons and limitations of the available materials. For example, only in recent months has it become possible to electrically readout the NV spin state at the level of a single center and significantly improve the scalability of NV center production. A number of ideas have been proposed to overcome the above-mentioned limitations. This paper summarizes the status of research in the area, details the most promising concepts for development, and discusses factors limiting progress as well as the most recent developments in the field. [ABSTRACT FROM AUTHOR]

Owing to its unique optical and spin properties, the nitrogen‐vacancy (NV) center holds the promise of a diamond‐based room‐temperature scalable quantum computer, but the numerous technical and physical issues are not yet overcome, especially the poor N to NV conversion. The NV and other color centers are, however, successfully used as multitasking quantum sensors, and open new routes in quantum sensing technologies. Most recently, several breakthroughs and demonstrations were achieved, shedding a new light on the feasibility of a NV‐based quantum computer. Herein, the recently developed method of charge‐assisted single defect engineering is reviewed. With a controlled charging of the involved species, it modifies the diffusion or kinetics of defect formation and acts as a catalyzer of the NV creation while hindering the formation of competing and perturbing defects such as divacancies or NVH. Very high NV creation yields up to 75% are obtained and the method is suitable to other impurity‐vacancy defects. Furthermore, it has positive consequences on the charge state stability and coherence time of the NV centers, which is as well discussed. Together with the possibility to nowadays deterministically implant single ions, this powerful method brings the scalability of NV qubits closer. [ABSTRACT FROM AUTHOR]

The ability to perform noninvasive and non-contact measurements of electric signals produced by action potentials is essential in biomedicine. A key method to do this is to remotely sense signals by the magnetic field they induce. Existing methods for magnetic field sensing of mammalian tissue, used in techniques such as magnetoencephalography of the brain, require cryogenically cooled superconducting detectors. These have many disadvantages in terms of high cost, flexibility and limited portability as well as poor spatial and temporal resolution. In this work we demonstrate an alternative technique for detecting magnetic fields generated by the current from action potentials in living tissue using nitrogen vacancy centres in diamond. With 50 pT/ Hz sensitivity, we show the first measurements of magnetic sensing from mammalian tissue with a diamond sensor using mouse muscle optogenetically activated with blue light. We show these proof of principle measurements can be performed in an ordinary, unshielded lab environment and that the signal can be easily recovered by digital signal processing techniques. Although as yet uncompetitive with probe electrophysiology in terms of sensitivity, we demonstrate the feasibility of sensing action potentials via magnetic field in mammals using a diamond quantum sensor, as a step towards microscopic imaging of electrical activity in a biological sample using nitrogen vacancy centres in diamond. [ABSTRACT FROM AUTHOR]

Magnetic field sensors based on quantum mechanic effects are often susceptible to misalignments of the magnetic field or need advanced procedures to compensate for these. Also, the record breaking sensitivities reported for superconducting quantum interference devices and alkali vapor magnetometers come along with large and complex experimental setups. The nitrogen vacancy center in diamond can be used to design a simple, small, and robust sensor without employing microwave radiation. By using compressed nanodiamond particles, it is possible to eliminate the need of an alignment of the magnetic field and still obtain the absolute magnetic flux density in a single measurement. In order to demonstrate the capabilities of this approach, a centimeter‐sized modified automotive demo board is employed as a complete sensor with a sensitivity of 78 μT/Hz. [ABSTRACT FROM AUTHOR]

We introduce a focussed ion beam (FIB) based ion implanter equipped with an electron beam ion source (EBIS), able to produce highly charged ions. As an example of its utilisation, we demonstrate the direct writing of nitrogen-vacancy centres in diamond using focussed, mask-less irradiation with Ar8+ ions with sub-micron three dimensional placement accuracy. The ion optical system was optimised and is characterised via secondary electron imaging. The smallest measured foci are below 200 nm, using objective aperture diameters of 5 and 10 µm, showing that nanoscale ion implantation using an EBIS is feasible. [ABSTRACT FROM AUTHOR]

No detailed information on in vivo biokinetics of CeO2 nanoparticles (NPs) following chronic low-dose inhalation is available. The CeO2 burden for lung, lung-associated lymph nodes, and major non-pulmonary organs, blood, and feces, was determined in a chronic whole-body inhalation study in female Wistar rats undertaken according to OECD TG453 (6 h per day for 5 days per week for a 104 weeks with the following concentrations: 0, 0.1, 0.3, 1.0, and 3.0 mg/m3, animals were sacrificed after 3, 12, 24 months). Different spectroscopy methods (ICP-MS, ion-beam-microscopy) were used for the quantification of organ burden and for visualization of NP distribution patterns in tissues. After 24 months of exposure, the highest CeO2 lung burden (4.41 mg per lung) was associated with the highest aerosol concentration and was proportionally lower for the other groups in a dose-dependent manner. Imaging techniques confirmed the presence of CeO2 agglomerates of different size categories within lung tissue with a non-homogenous distribution. For the highest exposure group, after 24 months in total 1.2% of the dose retained in the lung was found in the organs and tissues analyzed in this study, excluding lymph nodes and skeleton. The CeO2 burden per tissue decreased from lungs > lymph nodes > hard bone > liver > bone marrow. For two dosage groups, the liver organ burden showed a low accumulation rate. Here, the liver can be regarded as depot, whereas kidneys, the skeleton, and bone marrow seem to be dumps due to steadily increasing NP burden over time. [ABSTRACT FROM AUTHOR]

Background: Free-living walking activity and its contributing factors in ambulatory people with stroke is poorly investigated. Objective: Evaluating free-living walking activity and identifying factors associated with free-living walking activity. Methods: In this cross-sectional study, participants wore an accelerometer to measure their level of walking activity. They also completed the Berg Balance Scale (BBS) and the Timed Up and Go test for functional balance, the Falls Efficacy Scale, the 10-Metre Walk Test and the Geriatric Depression Scale to investigate the relation between the performance tests and walking activity. Results: The 38 analyzed participants were on average 62 (±11.4) years old and 66 (IQR 64.8) months post stroke. They took an average of 3048.3 ± 1983.1 steps, had 123.3 ± 61.3 walking bouts a day and walked for 32.5 ± 18.2 min a day. Their average speed was 90.3 ± 13.8 steps a minute. The multivariate linear analysis showed that the BBS was the only determinant that was significantly related to all outcomes, except walking bouts. Conclusion: Free-living walking activity levels in ambulatory people with chronic stroke are low. The BBS is an independent significant predictor of free-living walking activity. Free-living walking activity can be expressed in different outcomes measured by accelerometry. Free-living walking activity levels in ambulatory people with chronic stroke are low, therefore support to sustain walking in the own environment should be part of the rehabilitation program after stroke. Balance is an important related factor to free-living walking activity which needs attention during rehabilitation after stroke. [ABSTRACT FROM AUTHOR]

Industrial n-type Si wafers (resistivity of 5–10 Ω cm) were H+ ion implanted with energies between 0.75 and 2.00 MeV, and the electronic transport properties of the implanted layer (recombination lifetime, carrier diffusion coefficient, and front-surface and implanted-interface recombination velocities s1 and s2) were studied using photocarrier radiometry (PCR). A quantitative fitting procedure to the diffusing photoexcited free-carrier density wave was introduced using a relatively simple two-layer PCR model in lieu of the more realistic but substantially more complicated three-layer model. The experimental trends in the transport properties of H+-implanted Si layers extracted from the PCR amplitude and phase data as functions of implantation energy corroborate a physical model of the implanted layer in which (a) overlayer damage due to the light H+ ions decreases with increased depth of implantation at higher energies, (b) the implanted region damage close to the interface is largely decoupled from the overlayer crystallinity, and (c) the concentration of implanted H+ ions decreases at higher implantation energies at the interface, thus decreasing the degree of implantation damage at the interface proper. [ABSTRACT FROM AUTHOR]

Effective methods to generate colour centres in diamond and other wide band-gap materials are essential to the realisation of solid state quantum technologies based on such systems. Such methods have been the subject of intensive research effort in recent years. In this review, we bring together the various techniques used in the generation and positioning of colour centres in diamond: ion implantation, delta-doping, electron irradiation, laser writing and thermal annealing. We assess the roles and merits of each of these techniques in the formation of colour centres for different quantum technologies and consider future combinations of the techniques to meet the requirements of the most demanding applications. [ABSTRACT FROM AUTHOR]

Qubits based on colour centres in diamond became a prominent system for solid-state quantum information processing and sensing. But the deterministic creation of qubits and the control of their environment are still critical issues, preventing the development of a room-temperature quantum computer. We report on the high creation yield of NV centres of 75% (a tenfold enhancement) by charge-assisted defect engineering, together with an improvement of their spin coherence. The method strongly favours the formation and negative charge state of the NV centres with respect to intrinsic diamond, while it hinders the formation of competing and perturbing defects such as di-vacancies or NVH complexes. We evidence spectrally the charge state tuning of the implantation-induced vacancies from V0 to V−, key element of this Coulomb-driven engineering. The generality of the method is demonstrated using several donors (phosphorous, oxygen and sulphur) and applying it to other centres (SnV and MgV) in diamond. Nitrogen vacancy centres occur naturally in diamond and have potential uses in quantum computing but many applications require scalable, accurate fabrication methods. Here the authors demonstrate that tuning the doping modifies the dynamics of centre formation, increasing yields and coherence times. [ABSTRACT FROM AUTHOR]

Background: A stroke often results in gait impairments, activity limitations and restricted participation in daily life. Virtual reality (VR) has shown to be beneficial for improving gait ability after stroke. Previous studies regarding VR focused mainly on improvements in functional outcomes. As participation in daily life is an important goal for rehabilitation after stroke, it is of importance to investigate if VR gait training improves participation. The primary aim of this study is to examine the effect of VR gait training on participation in community-living people after stroke.Methods/design: The ViRTAS study comprises a single-blinded, randomized controlled trial with two parallel groups. Fifty people between 2 weeks and 6 months after stroke, who experience constraints with walking in daily life, are randomly assigned to the virtual reality gait training (VRT) group or the non-virtual reality gait training (non-VRT) group. Both training interventions consist of 12 30-min sessions in an outpatient rehabilitation clinic during 6 weeks. Assessments are performed at baseline, post intervention and 3 months post intervention. The primary outcome is participation measured with the Utrecht Scale for Evaluation of Rehabilitation-Participation (USER-P). Secondary outcomes are subjective physical functioning, functional mobility, walking ability, walking activity, fatigue, anxiety and depression, falls efficacy and quality of life.Discussion: The results of the study provide insight into the effect of VR gait training on participation after stroke.Trial Registration: Netherlands National Trial Register, Identifier NTR6215 . Registered on 3 February 2017. [ABSTRACT FROM AUTHOR]

Nanocapsules (NCS-DOX) with an oily core of selol and a shell of poly(methyl vinyl ether-co-maleic anhydride) covalently conjugated to doxorubicin were developed. These nanocapsules are spherical, with an average hydrodynamic diameter of about 170 nm, and with negative zeta potential. NCS-DOX effectively co-delivered the selol and the doxorubicin into 4T1 cells and changed the intracellular distribution of DOX from the nuclei to the mitochondria. Moreover, a significantly increased cytotoxicity against 4T1 cells was observed, which is suggestive of additive or synergic effect of selol and doxorubicin. In conclusion, PVM/MA nanocapsules are suitable platforms to co-deliver drugs into cancer cells. [ABSTRACT FROM AUTHOR]

Materials doped with the unstable isotope phosphorus 32 are promising candidates for use in brachytherapeutic applications. One way to dope a material with 32P is by ion implantation. However, the bombardment of the target with ions other than 32P due to impurities of the ion beam leads to unnecessary damages of the target, which might reduce its potential for medical applications. Furthermore, implanting a pre-selected activity of an unstable isotope into a target requires the repeated determination of the target's activity, which requires removing the target from the implantation chamber. This prolongs the total implantation time and requires handling the radioactive target multiple times, which in turn increases the risk of accidental exposure. We have incorporated an online-detector system into the implantation chamber of a 60 kV ion implanter that allowed us to determine the activity of the target without removing the target from the implantation chamber. We then used this system to investigate the implantation of ions with m = 38 u—instead of ions with m = 32 u—to reduce the fraction of other ions than 32P implanted into the target to reduce the induced damages. [ABSTRACT FROM AUTHOR]

Aluminum (Al) is one of the most common elements in the earth crust and increasingly used in food, consumer products and packaging. Its hazard potential for humans is still not completely understood. Besides the metallic form, Al also exists as mineral, including the insoluble oxide, and in soluble ionic forms. Representatives of these three species, namely a metallic and an oxidic species of Al-containing nanoparticles and soluble aluminum chloride, were applied to human intestinal cell lines as models for the intestinal barrier. We characterized physicochemical particle parameters, protein corona composition, ion release and cellular uptake. Different in vitro assays were performed to determine potential effects and molecular modes of action related to the individual chemical species. For a deeper insight into signaling processes, microarray transcriptome analyses followed by bioinformatic data analysis were employed. The particulate Al species showed different solubility in biological media. Metallic Al nanoparticles released more ions than Al2O3 nanoparticles, while AlCl3 showed a mixture of dissolved and agglomerated particulate entities in biological media. The protein corona composition differed between both nanoparticle species. Cellular uptake, investigated in transwell experiments, occurred predominantly in particulate form, whereas ionic Al was not taken up by intestinal cell lines. Transcellular transport was not observed. None of the Al species showed cytotoxic effects up to 200 µg Al/mL. The transcriptome analysis indicated mainly effects on oxidative stress pathways, xenobiotic metabolism and metal homeostasis. We have shown for the first time that intestinal cellular uptake of Al occurs preferably in the particle form, while toxicological effects appear to be ion-related. [ABSTRACT FROM AUTHOR]

Abstract: Nanoparticles, especially from carbon, have great potential in biomedicine. However, prior to clinical use, biocompatibility and biodistribution of these nanoobjects have to be assessed. Currently, particle detection is mostly based on surface‐bound labels, inevitably altering materials' properties by surface modification. Further obstacles include bleaching, dissociation of labels from the surface, weak emission of fluorophores due to insufficient tissue opacity or hampered light penetration or the need for specific excitation wavelengths. These characteristics greatly constrain employment of such nanoparticles to address complex analytical questions. To overcome these drawbacks, the use of intrinsic structural features of nanoobjects is highly desirable: the particle surface remains unchanged and the nanoobject exhibits its innate behavior. Thus, for sensitive detection and quantification, labels should be incorporated in the nanoparticle core, thereby avoiding cleavage and warranting unchanged surface characteristics. The incorporation of clinically approved radionuclide 32P into the lattice of nanodiamond particles using highly defined ion implantation is described here. The properties, uptake, and biodistribution are studied in vivo, in the developing hen's egg model (hen's egg test on chorioallantoic membrane assay). It is found that 32P labeling of diamond nanoparticles allows their reliable localization and sensitive quantification in a cost efficient, highly reliable, and safe way using available autoradiographic devices and analytical methods. [ABSTRACT FROM AUTHOR]

We demonstrate a technique for precision sensing of the temperature or the magnetic field by simultaneously driving two hyperfine transitions involving distinct electronic states of the nitrogen-vacancy center in diamond. Frequency modulation of both driving fields is used with either the same or opposite phase, resulting in the immunity to fluctuations in either the magnetic field or the temperature, respectively. In this way, a sensitivity of 1.4 nT Hz−1∕2 or 430 μK Hz−1∕2 is demonstrated. The presented technique only requires a single frequency demodulator and enables the use of phase-sensitive camera imaging sensors. A simple extension of the method utilizing two demodulators allows for simultaneous, independent, and high-bandwidth monitoring of both the magnetic field and the temperature. [ABSTRACT FROM AUTHOR]

Color centers in diamonds have shown promising potential for luminescent thermometry. So far, the nitrogen-vacancy (NV) color center has demonstrated a high sensitivity for optical temperature monitoring in biological systems. However, the NV center requires microwave excitation which can cause unwanted heating, and the NV is also sensitive to non-axial magnetic fields, both of which can result in inaccurate temperature measurements. To overcome this drawback, the silicon-vacancy (SiV) and germanium-vacancy (GeV) color centers in diamonds have recently been explored and have shown good optical temperature sensitivity owing to the temperature dependent wavelength optical zero-phonon line. Here, we report optical temperature measurements using the recently discovered tin-vacancy (SnV) color center in diamond and show sensitivity better than 0.2 K in 10 s integration time. Also, we compare the relative merits of SnV with respect to SiV and GeV for luminescent thermometry. These results illustrate that there are likely to be many future options for nanoscale thermometry using diamonds. [ABSTRACT FROM AUTHOR]

Amides are well known for their potential as anticaking agents for sodium chloride. We have investigated what is the ideal structure for an amide based anticaking agent and what features lead to effective anticaking. Through a series of experiments, we have found that a triple-branched structure, with the three branches radiating from the same nitrogen centre, is the only effective compound for preventing caking for sodium chloride. We conclude that this is likely due to bonding between the atoms of the amide functional group and the ions of sodium chloride, with an extra bond from the central nitrogen giving a strong attachment to the surface, thus leading to blocking of growth. We have also outlined a list of four categories, of which a compound must obey all of in order to act as an effective anticaking agent. [ABSTRACT FROM AUTHOR]

The increasing use of nanoparticles (NP) in commercial products requires elaborated techniques to detect NP in the tissue of exposed organisms. However, due to the low amount of material, the detection and exact localization of NP within tissue sections is demanding. In this respect, Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS) and Ion Beam Microscopy (IBM) are promising techniques, because they both offer sub-micron lateral resolutions along with high sensitivities. Here, we compare the performance of the non-material-consumptive IBM and material-consumptive ToF-SIMS for the detection of ZrO2 NP (primary size 9-10 nm) in rat lung tissue. Unfixed or methanol-fixed air-dried cryo-sections were subjected to IBM using proton beam scanning or to three-dimensional ToF-SIMS (3D ToF-SIMS) using either oxygen or argon gas cluster ion beams for complete sample sputtering. Some sample sites were analyzed first by IBM and subsequently by 3D ToF-SIMS, to compare results from exactly the same site. Both techniques revealed that ZrO2 NP particles occurred mostly agglomerated in phagocytic cells with only small quantities being associated to the lung epithelium, with Zr, S, and P colocalized within the same biological structures. However, while IBM provided quantitative information on element distribution, 3D ToF-SIMS delivered a higher lateral resolution and a lower limit of detection under these conditions. We, therefore, conclude that 3D ToF-SIMS, although not yet a quantitative technique, is a highly valuable tool for the detection of NP in biological tissue. [ABSTRACT FROM AUTHOR]

This article investigates the relationship between additive induced creeping and anticaking activity in sodium chloride. Through a series of creeping experiments and powder flow analysis, we establish a clear correlation between the amount of creeping and the anticaking effect of an additive. Habit modification is found not to be a sufficient condition for an anticaking agent. The correlation is explained by the fact that both creeping and anticaking require blocking of crystal growth. [ABSTRACT FROM AUTHOR]

Background. Virtual reality (VR) training is considered to be a promising novel therapy for balance and gait recovery in patients with stroke. Purpose. The aim of this study was to conduct a systematic literature review with meta-analysis to investigate whether balance or gait training using VR is more effective than conventional balance or gait training in patients with stroke. Data Sources. A literature search was carried out in the databases PubMed, Embase, MEDLINE, and Cochrane Library up to December 1, 2015. Study Selection. Randomized controlled trials that compared the effect of balance or gait training with and without VR on balance and gait ability in patients with stroke were included. Data Extraction and Synthesis. Twenty-one studies with a median PEDro score of 6.0 were included. The included studies demonstrated a significant greater effect of VR training on balance and gait recovery after stroke compared with conventional therapy as indicated with the most frequently used measures: gait speed, Berg Balance Scale, and Timed "Up & Go" Test. Virtual reality was more effective to train gait and balance than conventional training when VR interventions were added to conventional therapy and when time dose was matched. Limitations. The presence of publication bias and diversity in included studies were limitations of the study. Conclusions. The results suggest that VR training is more effective than balance or gait training without VR for improving balance or gait ability in patients with stroke. Future studies are recommended to investigate the effect of VR on participation level with an adequate follow-up period. Overall, a positive and promising effect of VR training on balance and gait ability is expected. [ABSTRACT FROM AUTHOR]

The nanometer-scale engineering of single nitrogen-vacancy (NV) centres in diamond can be obtained by low-energy (keV) nitrogen implantation with limited straggling. However, shallow NV centres (a few nanometres deep) generally have inferior overall properties than deeply implanted or deep native NV centres, due to the surface proximity. It has already been shown that the spin coherence time of shallow NVs is improved by overgrowth of a thin diamond layer. However the influence of the overgrowth on the survival, the optical properties and the charge state of the centres has not been studied in detail. In this article, we have overgrown three diamond samples (containing NV centres implanted at different depths) using different procedures. We show the successful overgrowth of a pattern of very shallow (2 nm) implanted NV centres using an optimised overgrowth process. Furthermore, the charge state of ensembles and single NV centres was found to be shifted from NV0 to NV− and stabilised in the negative charge state after overgrowth. The combination of low-energy high-resolution ion implantation and high-purity chemical vapour deposition (CVD) overgrowth procedures opens the way towards the fabrication of scalable and efficient quantum devices based on single defects in diamond. Left: implanted pattern of very shallow NV centres (depth ∼2 nm) using a pierced AFM tip. Right: same pattern after CVD overgrowth of a 4 μm-thick diamond layer. [ABSTRACT FROM AUTHOR]

This article investigates the relationship between additive induced creeping and anticaking activity in sodium chloride. Through a series of creeping experiments and powder flow analysis, we establish a clear correlation between the amount of creeping and the anticaking effect of an additive. Habit modification is found not to be a sufficient condition for an anticaking agent. The correlation is explained by the fact that both creeping and anticaking require blocking of crystal growth. [ABSTRACT FROM AUTHOR]

Iron(iii) meso-tartrate, a metal–organic complex, is a new anticaking agent for sodium chloride. A molecular structure in solution is proposed, based on a combination of experimental and molecular modelling results. We show that the active complex is a binuclear iron(iii) complex with two bridging meso-tartrate ligands. The iron atoms are antiferromagnetically coupled, resulting in a reduced paramagnetic nature of the solution. In solution, a water molecule coordinates to each iron atom as a sixth ligand, resulting in an octahedral symmetry around each iron atom. When the water molecule is removed, a flat and charged site is exposed, matching the charge distribution of the {100} sodium chloride crystal surface. This charge distribution is also found in the iron(iii) citrate complex, another anticaking agent. This gives a possible adsorption geometry on the crystal surface, which in turn explains the anticaking activity of the iron(iii) meso-tartrate complex. [ABSTRACT FROM AUTHOR]

The role that additives play in the growth of sodium chloride is a topic which has been widely researched but not always fully understood at an atomic level. Lead chloride (PbCl2) is one such additive which has been reported to have growth inhibition effects on NaCl {100} and {111}; however, no definitive evidence has been reported which details the mechanism of this interaction. In this investigation, we used the technique of surface x-ray diffraction to determine the interaction between PbCl2 and NaCl {100} and the structure at the surface. We find that Pb2+ replaces a surface Na+ ion, while a Cl− ion is located on top of the Pb2+. This leads to a charge mismatch in the bulk crystal, which, as energetically unfavourable, leads to a growth blocking effect. While this is a similar mechanism as in the anticaking agent ferrocyanide, the effect of PbCl2 is much weaker, most likely due to the fact that the Pb2+ ion can more easily desorb. Moreover, PbCl2 has an even stronger effect on NaCl {111}. [ABSTRACT FROM AUTHOR]