Magnetic colloidal single particles and dumbbells on a tilted washboard moiré pattern in a precessing external field.

We measure the dynamical behavior of colloidal singlets and dumbbells on an inclined magnetic moiré pattern, subject to a precessing external homogeneous magnetic field. At low external field strength single colloidal particles and dumbbells move everywhere on the pattern: at stronger external field strengths colloidal singlets and dumbbells are localized in generic locations. There are however nongeneric locations of flat channels that cross the moiré Wigner Seitz cell.

Topologically controlled synthesis of active colloidal bipeds.

Topological growth control allows to produce a narrow distribution of outgrown colloidal rods with defined and adjustable length. We use an external magnetic field to assemble paramagnetic colloidal spheres into colloidal rods of a chosen length. The rods reside above a metamorphic hexagonal magnetic pattern.

Simultaneous and independent topological control of identical microparticles in non-periodic energy landscapes.

Topological protection ensures stability of information and particle transport against perturbations. We explore experimentally and computationally the topologically protected transport of magnetic colloids above spatially inhomogeneous magnetic patterns, revealing that transport complexity can be encoded in both the driving loop and the pattern. Complex patterns support intricate transport modes when the microparticles are subjected to simple time-periodic loops of a uniform magnetic field.

Analysis of the Spinopelvic Parameters in Patients with Fragility Fractures of the Pelvis.

Background: We investigated the spinopelvic parameters of lumbar lordosis (LL), pelvic incidence (PI), pelvic tilt (PT) and sacral slope (SS) in patients with fragility fractures of the pelvis (FFPs). We hypothesized that these parameters differ from asymptomatic patients.

Methods: All patients treated for FFPs in a center of maximal care of the German Spine Society (DWG) between 2017 and 2021 were included.

Energy Dissipation in the Human Red Cell Membrane.

The membrane of the human red cell consists of a lipid bilayer and a so-called membrane skeleton attached on the cytoplasmic side of the bilayer. Upon the deformation of red cells, energy is dissipated in their cytoplasm and their membrane. As to the membrane, three contributions can be distinguished: (i) A two-dimensional shear deformation with the membrane viscosity as the frictional parameter; (ii) A motion of the membrane skeleton relative to the bilayer; (iii) A relative motion of the two monolayers of the bilayer.

Colloidal transport in twisted lattices of optical tweezers.

We simulate the transport of colloidal particles driven by a static and homogeneous drift force, and subject to the optical potential created by two lattices of optical tweezers. The lattices of optical tweezers are parallel to each other, shifted, and rotated by a twist angle. Due to a negative interference between the potential of the two lattices, flat channels appear in the total optical potential.

The Shape of Human Red Blood Cells Suspended in Autologous Plasma and Serum.

(1) Background: In almost all studies of the shape of the human red blood cell (RBC), the suspending medium was a salt solution supplemented with albumin. However, the ratio of thickness across the dimple region to the thickness of the rim (THR) depends on the albumin concentration. Values of the THR in the literature range from 0.

Gauge invariant and gauge dependent aspects of topological walking colloidal bipeds.

Paramagnetic colloidal spheres assemble to colloidal bipeds of various length in an external magnetic field. When the bipeds reside above a magnetic pattern and we modulate the direction of the external magnetic field, the rods perform topologically distinct classes of protected motion above the pattern. The topological protection allows each class to be robust against small continuous deformations of the driving loop of the external field.

Simultaneous polydirectional transport of colloidal bipeds.

Detailed control over the motion of colloidal particles is relevant in many applications in colloidal science such as lab-on-a-chip devices. Here, we use an external magnetic field to assemble paramagnetic colloidal spheres into colloidal rods of several lengths. The rods reside above a square magnetic pattern and are transported via modulation of the direction of the external magnetic field.

Colloidal trains.

Single and double paramagnetic colloidal particles are placed above a magnetic square pattern and are driven with an external magnetic field processing around a high symmetry direction of the pattern. The external magnetic field and that of the pattern confine the colloids into lanes parallel to a lattice vector of the pattern. The precession of the external field causes traveling minima of the magnetic potential along the direction of the lanes.

Hard topological versus soft geometrical magnetic particle transport.

The question of how a dissipative geometrical transport system changes towards a topological transport system is important to render a fragile transport into a robust transport. We show how a macroscopic magnetic topological transport of solid state spheres changes to a geometrical transport of ferrofluid droplets, when instead of a solid state object, soft matter is transported. The key difference when comparing solid objects with fluid droplets is the possibility to split a ferrofluid droplet into two droplets.

Edge transport at the boundary between topologically equivalent lattices.

Edge currents of paramagnetic colloidal particles propagate at the edge between two topologically equivalent magnetic lattices of different lattice constant when the system is driven with periodic modulation loops of an external magnetic field. The number of topologically protected particle edge transport modes is not determined by a bulk-boundary correspondence. Instead, we find a rich variety of edge transport modes that depend on the symmetry of both the edge and the modulation loop.

Predictors of Left Ventricular Remodeling After Myocardial Infarction in Patients With a Patent Infarct Related Coronary Artery After Percutaneous Coronary Intervention (from the Post-Myocardial Infarction Remodeling Prevention Therapy [PRomPT] Trial).

Left ventricular (LV) remodeling after myocardial infarction (MI) is a strong predictor of heart failure and mortality. The predictors of long-term remodeling after MI have been incompletely studied. We therefore examined the correlates of LV remodeling in patients with large ST-segment elevation myocardial infarction and a patent infarct artery after percutaneous 2coronary intervention (PCI) from the randomized Post-Myocardial Infarction Remodeling Prevention Therapy trial.

Wrinkled labyrinths in critical demixing ferrofluid.

A thin film of a critical ferrofluid mixture undergoes a sequence of transitions in a magnetic field. First the application of a field induces a critical demixing of the fluid into cylindrical droplets of the minority phase immersed in an extended majority phase. At a second critical field the cylindrical shape is destabilized and transforms into a labyrinth pattern.

Lattice symmetries and the topologically protected transport of colloidal particles.

The topologically protected transport of colloidal particles on top of periodic magnetic patterns is studied experimentally, theoretically, and with computer simulations. To uncover the interplay between topology and symmetry we use patterns of all possible two dimensional magnetic point group symmetries with equal lengths lattice vectors. Transport of colloids is achieved by modulating the potential with external, homogeneous but time dependent magnetic fields.

Molecular Explanation for the Abnormal Flux of Material into a Hot Spot in Ester Monolayers.

Langmuir monolayers of certain surfactants show a negative derivative of the surface pressure with respect to temperature. In these monolayers, a local temperature gradient leads to local yielding of the solid phase to a kinetically flowing liquid, so that the material flows toward the hotter regions that act as sinks. The accumulation of material leads to the formation of nonequilibrium multilamellar bubbles of different sizes.

Non reciprocal skewed rolling of a colloidal wheel due to induced chirality.

We use a rotating magnetic field to assemble an oblate cluster of paramagnetic colloidal particles. If the field is rotating about a horizontal axis, the cluster acts as a colloidal wheel rolling across the supporting glass surface. The motion is reversible upon switching the direction of rotation.

Toward the reconceptualization of the relationship between occupation and health and well-being.

Background: Foundational to the occupational therapy profession is the belief that engagement in occupation is health promoting; however, this belief fails to account for occupational engagement that may be risky or illness producing. Consensus regarding the nature of the relationship between occupation and health has yet to be achieved.

Purpose: The purpose of this study is to provide a comprehensive description of how the relationship between occupation and health and well-being is discussed within the occupational therapy and occupational science literature.

Magnetic field induced modulated phases in a ferrofluid lutidine silicone oil mixture.

A mixture of an ester based ferrofluid with silicone oil and 2,6-lutidine is exposed to an external magnetic field. We find a region of composition of the ternary mixture, where weak magnetic fields of the order of a few kA m induce a modulated phase with a pattern characterized by equilibrium size droplets of the minority phase immersed into the extended majority phase. While the pattern resembles in many ways the pattern of immiscible magnetic fluids, the dependence of the characteristic parameters of the pattern on the magnetic field are completely different than in immiscible fluids.

Transport on Active Paramagnetic Colloidal Networks.

We dynamically self-assemble an active paramagnetic colloidal network that ballistically transports nonmagnetic fluorescent colloidal particles on top of the network. The transport mechanism is put into effect by a directed hydrodynamic flow, created by the rotation of individual colloids forming the network. The ballistic transport is confined to the network, and tracer beads in meshes show a diffusive instead of a ballistic transport.

Creep and stress relaxation of human red cell membrane.

In contrast to most mechanical properties of the red cell, experimental information on stress relaxation (SR) of the membrane skeleton is scarce. On the other hand, many postulates or assumptions as to the value of the characteristic time of SR [Formula: see text] can be found in the literature. Here, an experiment is presented that allows measurement of [Formula: see text] up to values of about 10 h.

Topological protection of multiparticle dissipative transport.

Topological protection allows robust transport of localized phenomena such as quantum information, solitons and dislocations. The transport can be either dissipative or non-dissipative. Here, we experimentally demonstrate and theoretically explain the topologically protected dissipative motion of colloidal particles above a periodic hexagonal magnetic pattern.

Magnetic guidance of the magnetotactic bacterium Magnetospirillum gryphiswaldense.

Magnetospirillum gryphiswaldense is a magnetotactic bacterium with a permanent magnetic moment capable of swimming using two bipolarly located flagella. In their natural environment these bacteria swim along the field lines of the homogeneous geomagnetic field in a typical run and reversal pattern and thereby create non-differentiable trajectories with sharp edges. In the current work we nevertheless achieve stable guidance along curved lines of mechanical instability by using a heterogeneous magnetic field of a garnet film.

Toward the reconceptualization of the relationship between occupation and health and well-being.

Background: Foundational to the occupational therapy profession is the belief that engagement in occupation is health promoting; however, this belief fails to account for occupational engagement that may be risky or illness producing. Consensus regarding the nature of the relationship between occupation and health has yet to be achieved.

Purpose: The purpose of this study is to provide a comprehensive description of how the relationship between occupation and health and well-being is discussed within the occupational therapy and occupational science literature.