15 research outputs found
Targeted temperature management for adult out-of-hospital cardiac arrest: current concepts and clinical applications
Quantum Rings in Electromagnetic Fields
This is the author accepted manuscript. The final version is available from Springer via the DOI in this recordThis chapter is devoted to optical properties of so-called Aharonov-Bohm
quantum rings (quantum rings pierced by a magnetic flux resulting in AharonovBohm
oscillations of their electronic spectra) in external electromagnetic fields.
It studies two problems. The first problem deals with a single-electron AharonovBohm
quantum ring pierced by a magnetic flux and subjected to an in-plane (lateral)
electric field. We predict magneto-oscillations of the ring electric dipole moment.
These oscillations are accompanied by periodic changes in the selection rules for
inter-level optical transitions in the ring allowing control of polarization properties
of the associated terahertz radiation. The second problem treats a single-mode microcavity
with an embedded Aharonov-Bohm quantum ring which is pierced by a
magnetic flux and subjected to a lateral electric field. We show that external electric
and magnetic fields provide additional means of control of the emission spectrum
of the system. In particular, when the magnetic flux through the quantum ring is
equal to a half-integer number of the magnetic flux quanta, a small change in the
lateral electric field allows for tuning of the energy levels of the quantum ring into
resonance with the microcavity mode, thus providing an efficient way to control
the quantum ring-microcavity coupling strength. Emission spectra of the system are
discussed for several combinations of the applied magnetic and electric fields
On the origin of glioma
Glioma is the most frequent primary brain tumor of adults that has a presumably glial origin. Although our knowledge regarding molecular mechanisms and signaling pathways involved in gliomagenesis has increased immensely during the past decade, high-grade glioma remains a lethal disease with dismal prognosis. The failure of current therapies has to a large extent been ascribed the functional heterogeneity of glioma cells. One reason for this heterogeneity is most certainly the large number of variations in genetic alterations that can be found in high-grade gliomas. Another factor that may influence glioma heterogeneity could be the cell type from which the glioma is initiated. The cell of origin for glioma is still undefined, and additional knowledge about this issue may prove critical for a more complete understanding of glioma biology. Based on information from patients, developmental biology, and experimental glioma models, the most putative target cells include astrocytes, neural stem cells, and oligodendrocyte precursor cells, which are all discussed in more detail in this article. Animal modeling of glioma suggests that these three cell types have the capability to be the origin of glioma, and we have reason to believe that, depending on the initiating cell type, prognosis and response to therapy may be significantly different. Thus, it is essential to explore further the role of cellular origin in glioma