757 research outputs found
Graphene-plasmon polaritons: From fundamental properties to potential applications
With the unique possibilities for controlling light in nanoscale devices,
graphene plasmonics has opened new perspectives to the nanophotonics community
with potential applications in metamaterials, modulators, photodetectors, and
sensors. This paper briefly reviews the recent exciting progress in graphene
plasmonics. We begin with a general description for optical properties of
graphene, particularly focusing on the dispersion of graphene-plasmon
polaritons. The dispersion relation of graphene-plasmon polaritons of spatially
extended graphene is expressed in terms of the local response limit with
intraband contribution. With this theoretical foundation of graphene-plasmon
polaritons, we then discuss recent exciting progress, paying specific attention
to the following topics: excitation of graphene plasmon polaritons,
electron-phonon interactions in graphene on polar substrates, and tunable
graphene plasmonics with applications in modulators and sensors. Finally, we
seek to address some of the apparent challenges and promising perspectives of
graphene plasmonics.Comment: Invited minireview paper on graphene plasmon polaritons, 11 pages, 4
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Localized Surface Plasmons in Vibrating Graphene Nanodisks
Localized surface plasmons are confined collective oscillations of electrons
in metallic nanoparticles. When driven by light, the optical response is
dictated by geometrical parameters and the dielectric environment and plasmons
are therefore extremely important for sensing applications. Plasmons in
graphene disks have the additional benefit to be highly tunable via electrical
stimulation. Mechanical vibrations create structural deformations in ways where
the excitation of localized surface plasmons can be strongly modulated. We show
that the spectral shift in such a scenario is determined by a complex interplay
between the symmetry and shape of the modal vibrations and the plasmonic mode
pattern. Tuning confined modes of light in graphene via acoustic excitations,
paves new avenues in shaping the sensitivity of plasmonic detectors, and in the
enhancement of the interaction with optical emitters, such as molecules, for
future nanophotonic devices
Differences in Hypercholesterolemia and Atherogenesis Induced by Common Androgen Deprivation Therapies in Male Mice
Background-Treatment of prostate cancer often involves androgen deprivation therapy (ADT) by gonadotropin-releasing hormone (GnRH) receptor agonists, GnRH receptor antagonists, or orchiectomy. ADT may increase the rate of cardiovascular disease events, but recent clinical studies suggested that not all means of ADT carry the same risk, raising the possibility of non-testosterone-mediated effects of different forms of ADT on atherosclerosis. Here we compared effects of ADT on atherosclerosis in intact and orchiectomized Apoe-deficient mice. Methods and Results-Chow-fed Apoe-deficient mice were allocated to orchiectomy and/or monthly injections with the GnRH receptor agonist leuprolide or the GnRH receptor antagonist degarelix. Atherosclerosis was quantified at 26 weeks of age in the aortic arch by en face examination and in the aortic root by histology. In intact Apoe-deficient mice, all types of ADT reduced testosterone production to castration levels. Although hypercholesterolemia was accentuated in leuprolide-treated mice, the amount and composition of atherosclerosis was not different between the different types of ADT. In orchiectomized Apoe-deficient mice, leuprolide, but not degarelix, augmented hypercholesterolemia, changed body, thymus, and spleen weights, and increased atherosclerosis in the aortic root. No direct effects of the drugs were detectable on cytokine secretion from murine bone marrow-derived macrophages or on splenocyte proliferation. Conclusions-No differences in the development of atherosclerosis were detected among groups of intact Apoe-deficient mice treated with different types of ADT. A pro-atherogenic, possibly cholesterol-mediated, effect of leuprolide was seen in orchiectomized mice that might be relevant for understanding the potential cardiovascular risk associated with GnRH agonist-based ADT.The study was investigator-initiated and sponsored by Ferring Pharmaceuticals.S
Immune reconstitution syndrome presenting as probable AIDS-related lymphoma: a case report
We report an unusual case of HIV-related immune reconstitution inflammatory syndrome, presenting as suspected AIDS-related lymphoma. Symptoms, initial investigations including fine-needle biopsy and 18F-FDG PET/CT scan were highly compatible with high grade AIDS-related lymphoma, however subsequently IRIS was diagnosed. We discuss pitfalls in the interpretation of diagnostic results in ARL versus IRIS
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