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2D Visualization of the Psoriasis Transcriptome Fails to Support the Existence of Dual-Secreting IL-17A/IL-22 Th17 T Cells.
The present paradigm of psoriasis pathogenesis revolves around the IL-23/IL-17A axis. Dual-secreting Th17 T cells presumably are the predominant sources of the psoriasis phenotype-driving cytokines, IL-17A and IL-22. We thus conducted a meta-analysis of independently acquired RNA-seq psoriasis datasets to explore the relationship between the expression of IL17A and IL22. This analysis failed to support the existence of dual secreting IL-17A/IL-22 Th17 cells as a major source of these cytokines. However, variable relationships amongst the expression of psoriasis susceptibility genes and of IL17A, IL22, and IL23A were identified. Additionally, to shed light on gene expression relationships in psoriasis, we applied a machine learning nonlinear dimensionality reduction strategy (t-SNE) to display the entire psoriasis transcriptome as a 2-dimensonal image. This analysis revealed a variety of gene clusters, relevant to psoriasis pathophysiology but failed to support a relationship between IL17A and IL22. These results support existing theories on alternative sources of IL-17A and IL-22 in psoriasis such as a Th22 cells and non-T cell populations
Spin separation in cyclotron motion
Charged carriers with different spin states are spatially separated in a
two-dimensional hole gas. Due to strong spin-orbit interaction holes at the
Fermi energy have different momenta for two possible spin states travelling in
the same direction and, correspondingly, different cyclotron orbits in a weak
magnetic field. Two point contacts, acting as a monochromatic source of
ballistic holes and a narrow detector in the magnetic focusing geometry are
demonstrated to work as a tunable spin filter.Comment: 4 pages, 2 figure
Microwave Oscillations of a Nanomagnet Driven by a Spin-Polarized Current
We describe direct electrical measurements of microwave-frequency dynamics in
individual nanomagnets that are driven by spin transfer from a DC
spin-polarized current. We map out the dynamical stability diagram as a
function of current and magnetic field, and we show that spin transfer can
produce several different types of magnetic excitations, including small-angle
precession, a more complicated large-angle motion, and a high-current state
that generates little microwave signal. The large-angle mode can produce a
significant emission of microwave energy, as large as 40 times the
Johnson-noise background.Comment: 12 pages, 3 figure
``Smoke Rings'' in Ferromagnets
It is shown that bulk ferromagnets support propagating non-linear modes that
are analogous to the vortex rings, or ``smoke rings'', of fluid dynamics. These
are circular loops of {\it magnetic} vorticity which travel at constant
velocity parallel to their axis of symmetry. The topological structure of the
continuum theory has important consequences for the properties of these
magnetic vortex rings. One finds that there exists a sequence of magnetic
vortex rings that are distinguished by a topological invariant (the Hopf
invariant). We present analytical and numerical results for the energies,
velocities and structures of propagating magnetic vortex rings in ferromagnetic
materials.Comment: 4 pages, 3 eps-figures, revtex with epsf.tex and multicol.sty. To
appear in Physical Review Letters. (Postscript problem fixed.
Current driven switching of magnetic layers
The switching of magnetic layers is studied under the action of a spin
current in a ferromagnetic metal/non-magnetic metal/ferromagnetic metal spin
valve. We find that the main contribution to the switching comes from the
non-equilibrium exchange interaction between the ferromagnetic layers. This
interaction defines the magnetic configuration of the layers with minimum
energy and establishes the threshold for a critical switching current.
Depending on the direction of the critical current, the interaction changes
sign and a given magnetic configuration becomes unstable. To model the time
dependence of the switching process, we derive a set of coupled Landau-Lifshitz
equations for the ferromagnetic layers. Higher order terms in the
non-equilibrium exchange coupling allow the system to evolve to its
steady-state configuration.Comment: 8 pages, 2 figure. Submitted to Phys. Rev.
Magnetic unipolar features in con- ductivity of point contacts between normal and ferromagnetic d-metals (Co, Ni, Fe)
In nanocontacts between normal and ferromagnetic metals (N--F) abrupt changes
of the order of 1% are detected in differential resistance, dV/dI(V), versus
bias voltage, V, on achieving of high current densities, ~10^9 A/cm^2. These
features in dV/dI(V) are observed when the electron flow is directed from the
nonmagnetic metal into the ferromagnet and connected with magnetization
excitations in the ferromagnet induced by the current. Applying an external
magnetic field leads to a shift of the observed features to higher biasing
current, confirming the magnetic nature of the effect. Such effects are
observed for the non-ballistic (not spectral) regime of current flow in the
nanocontacts. Thus, the current induced magneto-conductance effects in
multilayered N--F structures (nanopillars) extensively studied in the recent
literature have much more general character and can be stimulated by elastic
electron scattering at single N--F interfaces.Comment: 10 pages, 9 figs., presented on NATO ARW: Electron Correlation In New
Materials And Nanosystems (19-23 Sept. 2005, Yalta, Ukraine
Spin Torques in Ferromagnetic/Normal Metal Structures
Recent theories of spin-current-induced magnetization reversal are formulated
in terms of a spin-mixing conductance . We evaluate from
first-principles for a number of (dis)ordered interfaces between magnetic and
non-magnetic materials. In multi-terminal devices, the magnetization direction
of a one side of a tunnel junction or a ferromagnetic insulator can ideally be
switched with negligible charge current dissipation.Comment: 4 pages, 1 figur
Wearable nanosensor-based hardware and software complex for dynamic cardiac monitoring
To date, continuous dynamic monitoring of the cardiovascular system is relevant for improvement of the quality of diagnosis of cardiac diseases. The equipment available for continuous cardiac monitoring operates in the standard frequency range, has a low resolution, and contains filters that limit signals in low and high frequencies. The development of wearable devices and high-resolution methods for dynamic cardiac monitoring to record signals in the range from 0 to 3500 Hz without filtering and averaging is of high priority. In addition, this will allow us to obtain new data on the atria and ventricles of the heart and to detect cardiovascular diseases at an early stage. A wearable hardware and software complex based on nanosensors was developed, and preliminary technical tests of the complex were carried out. An algorithm and a program were developed to detect micropotentials over the entire duration of the ECG signal except for the waves of cardiac pulses and sharp peaks in signal processing. Histograms were built for quantitative evaluation of micropotentials, and the total energy of micropotentials was calculated. Preliminary medical studies were carried out on volunteers
Cerebrovascular disorders in patients with type 2 diabetes mellitus and resistant hypertension
BACKGROUND: Diabetes mellitus (DM) and hypertension are risk factors for cerebral stroke, which are exacerbated by the combination of these diseases. Identifying the factors involved in the development of subclinical brain damage could change the therapeutic strategy for protecting the brain.AIM: to study severity of MRI- sings of brain damage and to identify factors associated with their development in patients with type 2 diabetes and RHTN.MATERIALS AND METHODS: 46 patients with type 2 DM and RHTN were included in a single-center observational uncontrolled study. Patients underwent brain MRI (1.5 Tesla) with calculation of Evans’s index (EI), clinical and lab examinations (HbA1c, glucose, insulin, C-peptide, leptin, resistin, TNF- α, hsCRP, blood aldosterone, insulin-like growth factor-1 (IGF-1)), measurement of the office and ambulatory blood pressure (BP), assessment of peripheral and cerebral vasoreactivity (test with hyperventilation and breath holding).RESULTS: The most frequent MR brain changes were white matter lesions (WML) in periventricular region (PVR) (89%), focal WML (52%) and expansion both of the ventricles (45%) and subarachnoid spaces (65%). Multiple direct correlations were revealed between parameters of carbohydrate metabolism with the degree of WML in PVR and the density of the MR-signal in the basal nucleus (BN), as well as with EI. Adipokines had a direct relationship with the size of the chiasmatic cistern and IE (for resistin), as well as with the density of the MR signal from the BN and IE (for leptin), that was also directly related to the IGF-1 level. The aldosterone level positively correlated with the size of III ventricle. An increase in TNF-α and hsCRP was accompanied by an increase in the density of the MR-signal in the PVR. Impairment of cerebrovascular reactivity is associated with an increase in the density of the MR-signal in PVR and with indirect signs of cerebral atrophy (increase in EI, the size of cisterns and lateral ventricles). Impairment of peripheral vasoreactivity had direct relationship with EI and the expansion of the III ventricle. There were no direct correlations between the severity of MR-sings of brain damage and BP levels.CONCLUSION: The combination of type 2 DM with RHTN is characterized by a high frequency of WML and liquorodynamics disturbances, which related with metabolic, neurohormonal and hemodynamic factors in the absence of a direct relationship with the degree of BP increas
Spintronics: Fundamentals and applications
Spintronics, or spin electronics, involves the study of active control and
manipulation of spin degrees of freedom in solid-state systems. This article
reviews the current status of this subject, including both recent advances and
well-established results. The primary focus is on the basic physical principles
underlying the generation of carrier spin polarization, spin dynamics, and
spin-polarized transport in semiconductors and metals. Spin transport differs
from charge transport in that spin is a nonconserved quantity in solids due to
spin-orbit and hyperfine coupling. The authors discuss in detail spin
decoherence mechanisms in metals and semiconductors. Various theories of spin
injection and spin-polarized transport are applied to hybrid structures
relevant to spin-based devices and fundamental studies of materials properties.
Experimental work is reviewed with the emphasis on projected applications, in
which external electric and magnetic fields and illumination by light will be
used to control spin and charge dynamics to create new functionalities not
feasible or ineffective with conventional electronics.Comment: invited review, 36 figures, 900+ references; minor stylistic changes
from the published versio
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