Magnon-Optic Effects with Spin-Wave Leaky Modes: Tunable Goos-Hänchen Shift and Wood's Anomaly.

We demonstrate numerically how a spin wave (SW) beam obliquely incident on the edge of a thin film placed below a ferromagnetic stripe can excite leaky SWs guided along the stripe. During propagation, leaky waves emit energy back into the layer in the form of plane waves and several laterally shifted parallel SW beams. This resonance excitation, combined with interference effects of the reflected and re-emitted waves, results in the magnonic Wood's anomaly and a significant increase of the Goos-Hänchen shift magnitude. This yields a unique platform to control SW reflection and transdimensional magnonic router that can transfer SWs from a 2D platform into a 1D guided mode.

P-type Inversion at the Surface of ß-Ga2O3 Epitaxial Layer Modified with Au Nanoparticles.

The electric properties and chemical and thermal stability of gallium oxide ß-Ga2O3 make it a promising material for a wide variety of electronic devices, including chemiresistive gas sensors. However, p-type doping of ß-Ga2O3 still remains a challenge. A ß-Ga2O3 epitaxial layer with a highly developed surface was synthesized on gold electrodes on a Al2O3 substrate via a Halide Vapor Phase Epitaxy (HVPE) method. The epitaxial layer was impregnated with an aqueous colloidal solution of gold nanoparticles with an average diameter of Au nanoparticle less than 5 nm. Electrical impedance of the layer was measured before and after modification with the Au nanoparticles in an ambient atmosphere, in dry nitrogen, and in air containing dimethyl sulfide C2H6S (DMS). After the impregnation of the ß-Ga2O3 epitaxial layer with Au nanoparticles, its conductance increased, and its electric response to air containing DMS had been inversed. The introduction of Au nanoparticles at the surface of the metal oxide was responsible for the formation of an internal depleted region and p-type conductivity at the surface.

Real-Space Observation of Magnon Interaction with Driven Space-Time Crystals.

The concept of space-time crystals (STC), i.e., translational symmetry breaking in time and space, was recently proposed and experimentally demonstrated for quantum systems. Here, we transfer this concept to magnons and experimentally demonstrate a driven STC at room temperature. The STC is realized by strong homogeneous microwave pumping of a micron-sized permalloy (Py) stripe and is directly imaged by scanning transmission x-ray microscopy (STXM). For a fundamental understanding of the formation of the STC, micromagnetic simulations are carefully adapted to model the experimental findings. Beyond the mere generation of a STC, we observe the formation of a magnonic band structure due to back folding of modes at the STC's Brillouin zone boundaries. We show interactions of magnons with the STC that appear as lattice scattering, which results in the generation of ultrashort spin waves (SW) down to 100-nm wavelengths that cannot be described by classical dispersion relations for linear SW excitation. We expect that room-temperature STCs will be useful to investigate nonlinear wave physics, as they can be easily generated and manipulated to control their spatial and temporal band structures.

Light guiding, bending, and splitting via local modification of interfaces of a photonic waveguide.

A general approach to the surface control of the localization, guiding, and redirecting of volume-mode light in photonic waveguides via tailoring their interfaces (surfaces) is proposed. The approach is demonstrated for dielectric rod-type photonic crystal slabs, whose regular and defect parts are distinguished by whether the nanocylinders are covered by metal caps. Thus, the rod-array part of the structure is not changed, while the local modifications are only applied to the interfaces. The basic functionalities, i.e., localized volume wave guiding, bending, and splitting are achievable. Selective dual-mode operation is possible due to the co-existence of a defect mode and a chainlike mode in one structure.

Daily longitudinal strain evaluation for left ventricular function monitoring in a 65-year-old female with reverse syndrome takotsubo and multiple triggering factors.

Among patients with takotsubo syndrome (TTS), reverse TTS (rTTS) constitutes 1-23% of all cases reported in the literature. The highest prevalence of rTTS is observed in intracranial hemorrhage, pheochromocytoma and severe infections. A CASE REPORT: The authors describe a case of a 65-year-old female with advanced multiple myeloma in whom rTTS was recognized on admission due to streptococcal sepsis. Other possible triggering factors included: anemia, blood transfusion, transient acute renal failure with electrolyte imbalance. ECG showed ST-segment depression in precordial leads and echocardiography revealed severe left ventricular (LV) dysfunction with apical sparing and with decreased ejection fraction (EF) and global longitudinal strain (GLS): 30 % and -10 %, respectively. Daily echocardiography showed gradual normalization of GLS as well as of regional longitudinal strain (RLS) within 8 days. The authors confirm the distinctness of rTTS including clinical, ECG, echocardiographic and laboratory findings and suggest the usefulness of daily longitudinal strain evaluation for LV function recovery monitoring.

Goos-Hänchen effect for Brillouin light scattering by acoustic phonons.

The lateral shift of an optical beam undergoing Brillouin light scattering on an acoustic wave (AW) in the total internal reflection geometry is studied theoretically. It is shown that the lateral shift depends on polarization (longitudinal or transversal) of the AW, as well as on the type of scattering process: a direct one, when the scattered wave undergoes a lateral shift at reflection from the interface, or a cascading one, when a fundamental frequency light beam is laterally shifted at reflection and then scattered on the AW.

The role of non-uniform magnetization texture for magnon-magnon coupling in an antidot lattice.

We numerically study the spin-wave dynamics in an antidot lattice based on a Co/Pd multilayer structure with reduced perpendicular magnetic anisotropy at the edges of the antidots. This structure forms a magnonic crystal with a periodic antidot pattern and a periodic magnetization configuration consisting of out-of-plane magnetized bulk and in-plane magnetized rims. Our results show a different behavior of spin waves in the bulk and in the rims under varying out-of-plane external magnetic field strength, revealing complex spin-wave spectra and hybridizations between the modes of these two subsystems. A particularly strong magnon-magnon coupling, due to exchange interactions, is found between the fundamental bulk spin-wave mode and the second-order radial rim modes. However, the dynamical coupling between the spin-wave modes at low frequencies, involving the first-order radial rim modes, is masked by the changes in the static magnetization at the bulk-rim interface with magnetic field changes. The study expands the horizons of magnonic-crystal research by combining periodic structural patterning and non-collinear magnetization texture to achieve strong magnon-magnon coupling, highlighting the significant role of exchange interactions in the hybridization.

Existence of edge modes in periodic microstrip transmission line.

The microstrip of modulated width is a realization of a one-dimensional photonic crystal operating in the microwave regime. Like any photonic crystal, the periodic microstrip is characterised by the presence of frequency bands and band gaps that enable and prohibit wave propagation, respectively. The frequency bands for microstrip of the symmetric unit cell can be distinguished by 0 or π Zak phase. The sum of these topological parameters for all bands below a given frequency gap determines the value of the surface impedance at the end of the microstrip. We demonstrate that edge modes are absent in a finite microstrip terminated at both ends in the centres of unit cells, but they can be induced by adding the defected cells. Edge modes present at both ends of the microstrip enable microwave tunneling with high transitivity in the frequency gap with or without a change in phase. This has been demonstrated experimentally and developed in detail using numerical simulations and model calculations. The investigated system, with a doublet of edge modes in the frequency gap, can be considered as a narrow passband filter of high selectivity and characterised by a significant group delay.

Collective Spin-Wave Dynamics in Gyroid Ferromagnetic Nanostructures.

Expanding upon the burgeoning discipline of magnonics, this research elucidates the intricate dynamics of spin waves (SWs) within three-dimensional nanoenvironments. It marks a shift from traditionally used planar systems to exploration of magnetization configurations and the resulting dynamics within 3D nanostructures. This study deploys micromagnetic simulations alongside ferromagnetic resonance measurements to scrutinize magnetic gyroids, periodic chiral configurations composed of chiral triple junctions with a period in nanoscale. Our findings uncover distinctive attributes intrinsic to the gyroid network, most notably the localization of collective SW excitations and the sensitivity of the gyroid's ferromagnetic response to the orientation of the static magnetic field, a correlation closely tied to the crystallographic alignment of the structure. Furthermore, we show that for the ferromagnetic resonance, multidomain gyroid films can be treated as a magnonic material with effective magnetization scaled by its filling factor. The implications of our research carry the potential for practical uses such as an effective, metamaterial-like substitute for ferromagnetic parts and lay the groundwork for radio frequency filters. The growing areas of 3D magnonics and spintronics present exciting opportunities to investigate and utilize gyroid nanostructures for signal processing purposes.

The Role of Progranulin (PGRN) in the Pathogenesis of Glioblastoma Multiforme.

Glioblastoma multiforme (GBM) represents the most common and aggressive malignant form of brain tumour in adults and is characterized by an extremely poor prognosis with dismal survival rates. Currently, expanding concepts concerning the pathophysiology of GBM are inextricably linked with neuroinflammatory phenomena. On account of this fact, the identification of novel pathomechanisms targeting neuroinflammation seems to be crucial in terms of yielding successful individual therapeutic strategies. In recent years, the pleiotropic growth factor progranulin (PGRN) has attracted significant attention in the neuroscience and oncological community regarding its neuroimmunomodulatory and oncogenic functions. This review of the literature summarizes and updates contemporary knowledge about PGRN, its associated receptors and signalling pathway involvement in GBM pathogenesis, indicating possible cellular and molecular mechanisms with potential diagnostic, prognostic and therapeutic targets in order to yield successful individual therapeutic strategies. After a review of the literature, we found that there are possible PGRN-targeted therapeutic approaches for implementation in GBM treatment algorithms both in preclinical and future clinical studies. Furthermore, PGRN-targeted therapies exerted their highest efficacy in combination with other established chemotherapeutic agents, such as temozolomide. The results of the analysis suggested that the possible implementation of routine determinations of PGRN and its associated receptors in tumour tissue and biofluids could serve as a diagnostic and prognostic biomarker of GBM. Furthermore, promising preclinical applications of PGRN-related findings should be investigated in clinical studies in order to create new diagnostic and therapeutic algorithms for GBM treatment.

Control of vortex chirality in a symmetric ferromagnetic ring using a ferromagnetic nanoelement.

Controlling the vortex chirality in ferromagnetic nanodots and nanorings has been a topic of investigation for the last few years. Many control methods have been proposed and it has been found that the control is related to the breaking of the circular symmetry of the ring. In this paper, we present a theoretical study demonstrating the control of chirality in a symmetrical ferromagnetic nanoring by breaking the circular symmetry of the system by placing an elongated ferromagnetic nanoelement inside the ring. Here, the stray magnetostatic field exerted by the asymmetrically placed nanoelement determines the movement of the domain walls upon re-magnetization of the nanoring and the resulting chirality in remanence. Thus, the use of a nanoelement not only allows control of the chirality of the vortex state in an isolated ring, but also offers an opportunity to control magnetization in denser nanoring systems, as well as for spintronic and magnonic applications.

Stabilization and racetrack application of asymmetric Néel skyrmions in hybrid nanostructures.

Magnetic skyrmions, topological quasiparticles, are small stable magnetic textures that possess intriguing properties and potential for data storage applications. Hybrid nanostructures comprised of skyrmions and soft magnetic material can offer additional advantages for developing skyrmion-based spintronic and magnonic devices. We show that a Néel-type skyrmion confined within a nanodot placed on top of a ferromagnetic in-plane magnetized stripe produces a unique and compelling platform for exploring the mutual coupling between magnetization textures. The skyrmion induces an imprint upon the stripe, which, in turn, asymmetrically squeezes the skyrmion in the dot, increasing their size and the range of skyrmion stability at small values of Dzyaloshinskii-Moriya interaction, as well as introducing skyrmion bi-stability. Finally, by exploiting the properties of the skyrmion in a hybrid system, we demonstrate unlimited skyrmion transport along a racetrack, free of the skyrmion Hall effect.

Effects of sling and voluntary constraint during constraint-induced movement therapy for the arm after stroke: a randomized, prospective, single-centre, blinded observer rated study.

OBJECTIVE: To determine whether a combination of constraint-induced movement therapy and physiotherapy in stroke patients using different constraint regimens (sling versus voluntary constraint) changes or reduces motor deficits, the amount of functional use of the arm and whether the effects of treatment continue after 12 months. DESIGN: Forty-seven stroke patients were stratified and randomly divided into intensive physiotherapy programmes focused on regaining arm functions. SETTING: Neurorehabilitation Unit of IInd Department of Neurology at Institute of Psychiatry and Neurology in Warsaw. SUBJECT: Patients were randomly allocated to: the sling-constraint group (n = 24) or to the voluntary-constraint group (n = 23). INTERVENTIONS: Massed practice with the paretic arm (5 hours/day for 15 consecutive working days). Sling-constraint group had their arm immobilized in a hemi-sling during therapy. In addition, individual, 1-hour physiotherapy sessions were conducted in both groups. MAIN MEASURES: Rivermead Motor Assessment (RMA) Arm scale, (0-15), Motor Activity Log - Quality of Movement (MAL-QOM) (0-5 for 30 daily tasks). RESULTS: There was no significant difference between groups after therapy (MAL-QOM mean change for sling group 0.78, SD = 0.46 and for voluntary-constraint group 0.84, SD = 0.48; P = 0.687). All treated patients retained mean gains in real-world arm use (MAL-QOM) mean scores after 12 months follow-up compared with posttreatment values but there was no significant difference between groups (comparison of estimated mean change of MAL-QOM stated 0.23. 95% confidence interval = -0.04-0.50). CONCLUSION: Voluntary activity constraint in the intact arm is equivalent to sling, standard constraint during massed practice of paretic arm.

Pandemic decrease of in-person physiotherapy as a factor in parent perceived decline in function in children with neuromuscular disorders.

PURPOSE: Restrictions related to the COVID-19 pandemic can negatively affect patients who require physiotherapy. This study aimed to analyze the consequences of limited physiotherapy on the functional state of children with neuromuscular diseases (NMD). In addition, the caregivers' well-being and caregiver opinions on physiotherapy were analyzed. METHODS: A questionnaire was shared with parents of children with NMD immediately after the COVID-19 lockdown. The survey included questions regarding the physical and mental condition of children and parents before the pandemic and during lockdown as well as their views on physiotherapy and telephysiotherapy. Statistical analysis was performed using the Wilcoxon Matched-Pairs Signed Ranks test, Spearman's Rank Correlation test, McNemar test, and Chi-square test. RESULTS: Parents of 235 children participated in the study. Results indicated that children devoted more time to physiotherapy before the pandemic than during the lockdown period, which was true for those living in cities and the countryside. The functional state of 50.2% of the children deteriorated during the lockdown, in the opinion of their parents. Significant correlations were found between limited physiotherapy time and the deterioration of children's functional condition, ability to maintain a standing position, and increased anxiety. The majority of parents reported increased levels of fear and anxiety (72.8%), fatigue (67.7%), and pain (53.2%). In-person physiotherapy was rated significantly higher than telephysiotherapy by parents. CONCLUSIONS: Limited access to physiotherapy and shorter therapy times may lead to functional deterioration in children with NMD, but this assumption needs to be objectively confirmed. According to the parents' opinions, telephysiotherapy is less beneficial than direct physiotherapy but may support therapy conducted directly by a physiotherapist. Results based on subjective parental opinions may be helpful in planning future projects.

Reconfigurable Magnonic Crystals Based on Imprinted Magnetization Textures in Hard and Soft Dipolar-Coupled Bilayers.

Reconfigurable magnetization textures offer control of spin waves with promising properties for future low-power beyond-CMOS systems. However, materials with perpendicular magnetic anisotropy (PMA) suitable for stable magnetization-texture formation are characterized by high damping, which limits their applicability in magnonic devices. Here, we propose to overcome this limitation by using hybrid structures, i.e., a PMA layer magnetostatically coupled to a low-damping soft ferromagnetic film. We experimentally show that a periodic stripe-domain texture from a PMA layer is imprinted upon the soft layer and induces a nonreciprocal dispersion relation of the spin waves confined to the low-damping film. Moreover, an asymmetric bandgap features the spin-wave band diagram, which is a clear demonstration of collective spin-wave dynamics, a property characteristic for magnonic crystals with broken time-reversal symmetry. The composite character of the hybrid structure allows for stabilization of two magnetic states at remanence, with parallel and antiparallel orientation of net magnetization in hard and soft layers. The states can be switched using a low external magnetic field; therefore, the proposed system obtains an additional functionality of state reconfigurability. This study offers a link between reconfigurable magnetization textures and low-damping spin-wave dynamics, providing an opportunity to create miniaturized, programmable, and energy-efficient signal processing devices operating at high frequencies.

Development of early comprehensive stroke inpatient rehabilitation in Poland - current status and future requirements.

BACKGROUND AND PURPOSE: Every stroke patient should undergo early rehabilitation. We aimed to evaluate accessibility, development and needs in early stroke inpatient rehabilitation in Poland. MATERIAL AND METHODS: A questionnaire evaluating rehabilitation departments was prepared and sent (in 2004 and 2008) to rehabilitation wards in Poland, where stroke patients are treated and undergo early rehabilitation. We divided departments into classes: class A - having comprehensive rehabilitation (physiotherapy minimum 60 minutes/day, speech therapy minimum 30 minutes/5 days/week, rehabilitation of other cognitive impairments minimum 30 minutes/5 days/week, group physiotherapy); B - having the possibility of all types of therapy, but done less frequently; C - physiotherapy and speech therapy; D - physiotherapy and cognitive rehabilitation; E - only physiotherapy. RESULTS: In 2004, we obtained responses from 115 of 172 (66.9%) rehabilitation departments. According to prespecified criteria there were 11 class A, 31 class B, 28 class C, 4 class D, and 41 class E wards. In 2008, we received response from 89 of 149 (59.7%) rehabilitation departments. According to prespecified criteria there were 17 class A, 40 class B, 22 class C, 0 class D, and 10 class E wards. In 2004, 159 beds and in 2008, 294 beds in class A departments were available for stroke patients. The minimal number of needed but lacking beds was 604 in 2004 and 469 in 2008. CONCLUSIONS: Development of departments providing early comprehensive stroke rehabilitation from 2004 to 2008 is marked, but still insufficient. In 2008, 19% of rehabilitation departments could provide comprehensive stroke rehabilitation and this was 38.5% of beds actually needed.

Nonresonant amplification of spin waves through interface magnetoelectric effect and spin-transfer torque.

We present a new mechanism for manipulation of the spin-wave amplitude through the use of the dynamic charge-mediated magnetoelectric effect in ultrathin multilayers composed of dielectric thin-film capacitors separated by a ferromagnetic bilayer. Propagating spin waves can be amplified and attenuated with rising and decreasing slopes of the oscillating voltage, respectively, locally applied to the sample. The way the spin accumulation is generated makes the interaction of the spin-transfer torque with the magnetization dynamics mode-selective and restricted to some range of spin-wave frequencies, which is contrary to known types of the spin-transfer torque effects. The interfacial nature of spin-dependent screening allows to reduce the thickness of the fixed magnetization layer to a few nanometers, thus the proposed effect significantly contributes toward realization of the magnonic devices and also miniaturization of the spintronic devices.

Agreement and reliability of repeated bedside respiratory muscle strength measurements in acute and subacute stroke.

BACKGROUND AND PURPOSE: Many stroke trials include maximal inspiratory pressure (MIP), maximal expiratory pressure (MEP), and sniff nasal inspiratory pressure (SNIP) outcome measurements. However, data on agreement and reliability of repeated MIP, MEP, and SNIP measurements in acute and subacute stroke patients are scarce. METHODS: This study employed a test-retest design. Eighteen patients (seven female) with mean (SD) age 59 (14.5) years were recruited from neurological wards. Median (range) time since first stroke was 50.5 (21-128) days. MIP, MEP, and SNIP were measured repeatedly in three testing sessions (S1-3) conducted within 24 h and following international standards. Intra-rater agreement between testing sessions was analyzed using the Bland-Altman method. Test-retest reliability was analyzed using intra-class correlation coefficient (ICC). Association between individual measurement variability, time poststroke, and level of stroke impairment was analyzed using Spearman's rho. RESULTS: Mean difference and 95% limits of agreement for MIP were -0.40 (-23.02, 22.22) cmH2 O between S1 and S2, and 2.14 (-12.79, 16.99) cmH2 O between S2 and S3; for MEP, -4.56 (-29.01, 19.90) cmH2 O between S1 and S2, and 0.29 (-24.28, 24.87) cmH2 O between S2 and S3; and for SNIP, -10.56 (-38.48, 17.37) cmH2 O between S1 and S2, and -6.06 (-27.32, 15.20) cmH2 O between S2 and S3. ICCs for MIP, MEP, and SNIP were ≥0.9 throughout. There were no strong correlations between individual measurement variability and time poststroke or level of stroke impairment. DISCUSSION: MIP, MEP, and SNIP in acute and subacute stroke patients show good test-retest reliability for group averages; however, absolute agreement can vary considerably for some individuals.

Resonant subwavelength control of the phase of spin waves reflected from a Gires-Tournois interferometer.

Subwavelength resonant elements are essential building blocks of metamaterials and metasurfaces, which have revolutionized photonics. Despite similarities between different wave phenomena, other types of interactions can make subwavelength coupling significantly distinct; its investigation in their context is therefore of interest both from the physics and applications perspective. In this work, we demonstrate a fully magnonic Gires-Tournois interferometer based on a subwavelength resonator made of a narrow ferromagnetic stripe lying above the edge of a ferromagnetic film. The bilayer formed by the stripe and the film underneath supports two propagative spin-wave modes, one strongly coupled with spin waves propagating in the rest of the film and another almost completely reflected at the ends of the bilayer. When the Fabry-Perot resonance conditions for this mode are satisfied, the weak coupling between both modes is sufficient to achieve high sensitivity of the phase of waves reflected from the resonator to the stripe width and, more interestingly, also to the stripe-film separation. Such spin-wave phase manipulation capabilities are a prerequisite for the design of spin-wave metasurfaces and may stimulate development of magnonic logic devices and sensors detecting magnetic nanoparticles.

Morphology of Ga2O3 Nanowires and Their Sensitivity to Volatile Organic Compounds.

Gas sensitive structures made of nanowires exhibit extremally large specific surface area, and a great number of chemically active centres that can react with the ambient atmosphere. This makes the use of nanomaterials promising for super sensitive gas sensor applications. Monoclinic ß-Ga2O3 nanowires (NWs) were synthesized from metallic gallium at atmospheric pressure in the presence of nitrogen and water vapor. The nanowires were grown directly on interdigitated gold electrodes screen printed on Al2O3 substrates, which constituted the gas sensor structure. The observations made with transmission electron microscope (TEM) have shown that the nanowires are monocrystalline and their diameters vary from 80 to 300 nm with the average value of approximately 170 nm. Au droplets were found to be anchored at the tips of the nanowires which may indicate that the nanowires followed the Vapor-Liquid-Solid (VLS) mechanism of growth. The conductivity of ß-Ga2O3 NWs increases in the presence of volatile organic compounds (VOC) even in the temperature below 600 °C. The gas sensor based on the synthesized ß-Ga2O3 NWs shows peak sensitivity to 100 ppm of ethanol of 75.1 at 760 °C, while peak sensitivity to 100 ppm of acetone is 27.5 at 690 °C.