1,062 research outputs found
Upper bound of the charge diffusion constant in holography
We investigate the upper bound of charge diffusion constant in holography.
For this purpose, we apply the conjectured upper bound proposal related to the
equilibration scales () to the
Einstein-Maxwell-Axion model. () is defined
as the collision point between the diffusive hydrodynamic mode and the first
non-hydrodynamic mode, giving rise to the upper bound of the diffusion constant
at low temperature as . We show
that the upper bound proposal also works for the charge diffusion and
(), at low , is determined by and the
scaling dimension of an infra-red operator as , as for
other diffusion constants. However, for the charge diffusion, we find that the
collision occurs at real , while it is complex for other
diffusions. In order to examine the universality of the conjectured upper
bound, we also introduce a higher derivative coupling to the
Einstein-Maxwell-Axion model. This coupling is particularly interesting since
it leads to the violation of the \textit{lower} bound of the charge diffusion
constant so the correction may also have effects on the \textit{upper} bound of
the charge diffusion. We find that the higher derivative coupling does not
affect the upper bound so that the conjectured upper bound would not be easily
violated.Comment: v1: 23 pages, 10 figures; v2: minor edits, references adde
Politische Bildung, Interkulturalität und Integration
Der Beitrag stellt die Ansätze der Politikdidaktik zum gesellschaftlichen Zusammenhalt unter dem Aspekt der Interkulturalität dar. Zunächst wird auf die Bedeutung interkultureller Bildung für die Politikdidaktik verwiesen. Danach wird der Beitrag politischer Bildung für die Integration untersucht. Schließlich wird der Blick auf die Kompetenzorientierung im Kontext von Interkulturalität gelenkt
Holography and magnetohydrodynamics with dynamical gauge fields
Within the framework of holography, the Einstein-Maxwell action with
Dirichlet boundary conditions corresponds to a dual conformal field theory in
presence of an external gauge field. Nevertheless, in many real-world
applications, e.g., magnetohydrodynamics, plasma physics, superconductors, etc.
dynamical gauge fields and Coulomb interactions are fundamental. In this work,
we consider bottom-up holographic models at finite magnetic field and (free)
charge density in presence of dynamical boundary gauge fields which are
introduced using mixed boundary conditions. We numerically study the spectrum
of the lowest quasi-normal modes and successfully compare the obtained results
to magnetohydrodynamics theory in dimensions. Surprisingly, as far as the
electromagnetic coupling is small enough, we find perfect agreement even in the
large magnetic field limit. Our results prove that a holographic description of
magnetohydrodynamics does not necessarily need higher-form bulk fields but can
be consistently derived using mixed boundary conditions for standard gauge
fields.Comment: 54 pages, 22 figure
Clinical Characteristics of Renal Transplant Recipients that Underwent Urologic Surgery for de novo Disease Before and After Transplantation
The pre-transplantation goal of the urologist is the optimization of urinary tract condition. Therefore, urologic surgery may be needed before or after renal transplantation. We analyzed the results of urologic surgery performed because of de novo urologic diseases. Between January 1986 and January 2001, 281 patients underwent renal transplantation, and 23 urologic surgical procedures were performed on 21 transplant recipients before or after renal transplantation because of de novo urologic diseases. By review the major reasons for urologic surgery in recipients were polycystic kidney diseases, vesicoureteral reflux, and dysfunctional voiding disorders. Nineteen surgical corrective procedures were done average 2.9 months before transplantation. The mortality rate was 10.5%. Four patients underwent urologic surgery at an average 57.5 months after transplantation. We highlight the fact that patients with uremia are vulnerable to surgical complications, and conclude that more intensive long-term urologic follow-ups should be conducted on recipients
Cu doping effects on the electronic structure of Fe1-xCuxSe
Using angle-resolved photoemission spectroscopy (ARPES), we studied the
evolution of the electronic structure of Fe1-xCuxSe from x = 0 to 0.10. We
found that the Cu dopant introduces extra electron carriers. The hole bands
near the gamma point are observed to steadily shift downward with increasing
doping and completely sink down below the Fermi level (EF) for x > 0.05.
Meanwhile, the electron pocket near the M point becomes larger but loses the
spectral weight near EF. We also observed that effective mass of the electron
band near the M point increases with doping. Our result explains why
superconductivity disappears and metal insulator transition (MIT) like behavior
occurs upon Cu doping in terms of electronic structure, and provide insight
into emergent magnetic fluctuation in Fe1-xCuxSe
The Effect of Clonidine Pretreatment on Epidural Resiniferatoxin in a Neuropathic Pain Rat Model
Resiniferatoxin (RTX) is an ultrapotent synthetic TRPV1 (transient receptor potential vanilloid subtype 1) agonist with significant initial transient hyperalgesia followed by a prolonged analgesic effect in response to thermal stimulus. Using a rat model of neuropathic pain, we evaluated the effect of pretreatment with clonidine-which has been shown to relieve intradermal capsaicin-induced hyperalgesia-on the initial hyperalgesic response and the thermal analgesic property of RTX. Thirty-six male rats were divided into 6 treatment groups (n=6 each):RTX 500ng, RTX 1μg, clonidine 20μg (Cl), Cl+RTX 500ng, Cl+RTX 1μg, or normal saline 20μL (control). We evaluated the short-term (180min) and long-term (20 days) analgesic effects of RTX after thermal stimulation and mechanical stimulation. RTX had significant initial transient hyperalgesia followed by a prolonged analgesic effect in response to the thermal stimulus, but the RTX 500ng and RTX 1μg groups showed no initial short-term thermal hyperalgesic responses when pretreated with clonidine. The Cl+RTX 1μg ratsʼ behavior scores indicated that they were more calm and comfortable compared to the RTX 1μg rats. Even though we cannot precisely confirm that pretreatment with clonidine potentiates or adds to the analgesic effect of RTX, clonidine pretreatment with epidural RTX eliminated the initial RTX-associated hyperalgesic response and systemic toxicity in this neuropathic pain rat model
Anesthetic management of penetrating neck injury patient with embedded knife -A case report-
Penetrating neck injuries can be a fatal event and they are difficult to manage for both surgeons and anesthesiologists. So, adequate preoperative evaluation is important to improve the patients' outcomes, but this can not be done for hemodynamically unstable or uncooperative patient. Here we present our clinical experience with a patient with a penetrating neck injury and who was hemodynamically stable, but she was uncooperative and the knife was still embedded in her neck. The surgical exploration and bronchoscopic examination were successfully done under monitored anesthesia care
Early Experience with Hyaluronic Acid Instillation to Assist with Visual Internal Urethrotomy for Urethral Stricture
Successful Chemotherapy Following Autologous Stem Cell Transplantation in Multiple Myeloma and Multi-organ Dysfunction with Infiltration of Eosinophils: A Case Report
Eosinophils are derived from hematopoietic stem cells. Peripheral blood eosinophilia is defined as an absolute eosinophil count of ≥0.5×109/L. Eosinophilia is classified into primary or clonal eosinophilia, secondary eosinophilia, and idiopathic categories including idiopathic hypereosinophilic syndrome. Both hematopoietic and solid neoplasms may be associated with peripheral blood eosinophilia, but multiple myeloma is rarely associated with eosinophilia. We now report the case of a 31-year-old man with multiple myeloma associated with marked eosinophilia who developed multiple organ dysfunction with infiltration of eosinophils. He recovered after treatment with chemotherapy followed by autologous stem cell transplantation
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