13 research outputs found
Surface plasmon induced quantum interference at meta-material interface
In this work we investigate quantum interference in a four-level atom coupled
to a negative index meta-material (NIMM) plasmonic reservoir that supports both
TE and TM polarized surface plasmons (SP). This provides more options to
control SP interaction with emitters and hence more control of spontaneous
emission decays and spectrum. The spectrum depends critically on parameters
like the reservoir parameters, mode frequency, frequency dependent electric
permittivity and magnetic permeability, and the location of the atom. We report
orders of magnitude enhancement in the reservoir-modified decays and spectrum
compared to free space case. The rich atomic and plasmonic parameters provide a
wide range of flexibility and more options to control emission spectrum that
suits practical applications.Comment: 30 pages , 8 figures , research wor
Quantum informatics with plasmonic metamaterials
Surface polaritons at a meta-material interface are proposed as qubits. The
SP fields are shown to have low losses, subwavelength confinement and can
demonstrate very small modal volume. These important properties are used to
demonstatre interesting applications in quantum information, i.e., coherent
control of weak fields and large Kerr nonlinearity at the low photon level
Coherent control of low loss surface polaritons
We propose fast all-optical control of surface polaritons (SPs) by placing an
electromagnetically induced transparency (EIT) medium at an interface between
two materials. EIT provides longitudinal compression and a slow group velocity
while matching properties of the two materials at the interface provides strong
transverse confinement. In particular we show that an EIT medium near the
interface between a dielectric and a negative-index metamaterial can establish
tight longitudinal and transverse confinement plus extreme slowing of SPs, in
both transverse electric and transverse magnetic polarizations, while
simultaneously avoiding losses.Comment: 4 pages, 5 figure
Molecular generation and characterization of an efficient recombinant vaccine for avian influenza A/H5N8 in Saudi Arabia
Purpose: To characterize a highly pathogenic avian influenza (HPAI) H5N8 for engineering recombinant 6-+ 2 vaccine strain based on reverse genetic technology.
Methods: A total of 135 swab samples from various birds were collected from different parts of Saudi Arabia as part of an influenza surveillance activity. The samples were checked for influenza virus infection using reverse transcriptase-polymerase chain reaction (RT-PCR). Furthermore, Avian influenza H5N8 (A/chicken/KSA/1-NRC/2018), was used for the generation of H5N8 vaccine strain. The vaccine was tested on specific pathogen-free (SPF) chicken purchased from a local market.
Results: The results indicate that the candidate vaccine (rgH5N8/KSA) induced specific neutralizing antibodies in chicken, and thereby protected the chickens from subsequent infections of H5N8.
Conclusion: The study reinforces the development of a vaccine against avian influenza H5N8 virus isolated in Saudi Arabia, suggesting its possible application against the influenza virus associated with bird fl
Imaging of adult brainstem gliomas
Brainstem gliomas (BSGs) are uncommon in adults accounting for about 2% of all intracranial neoplasms. They are often phenotypically low-grade as compared to their more common paediatric counterparts. Since brainstem biopsies are rarely performed, these tumours are commonly classified according to their MR imaging characteristics into 4 subgroups (a) diffuse intrinsic low-grade gliomas, (b) enhancing malignant gliomas, (c) focal tectal gliomas and (d) exophytic gliomas/other subtypes. The prognosis and treatment is variable for the different types and is almost similar to adult supratentorial gliomas. Radiotherapy (RT) with adjuvant chemotherapy is the standard treatment of diffuse low-grade and malignant BSGs, whereas, surgical resection is limited to the exophytic subtypes. Review of previous literature shows that the detailed imaging of adult BSGs has not received significant attention. This review illustrates in detail the imaging features of adult BSGs using conventional and advanced MR techniques like diffusion weighted imaging (DWI), diffusion tensor imaging (DTI), MR perfusion weighted imaging (PWI), MR spectroscopy (MRS), as well as 18 F-fluoro-ethyl-tyrosine positron emission tomography (18F-FET/PET). We have discussed the pertinent differences between childhood and adult BSGs, imaging mimics, prognostic factors and briefly reviewed the treatment options of these tumours