| 1. |
- Bastide, Matthieu F, et al.
(author)
-
Pathophysiology of L-dopa-induced motor and non-motor complications in Parkinson's disease.
- 2015
-
In: Progress in Neurobiology. - : Elsevier BV. - 1873-5118 .- 0301-0082. ; 132:Jul 21, s. 96-168
-
Research review (peer-reviewed)abstract
- Involuntary movements, or dyskinesia, represent a debilitating complication of levodopa (L-dopa) therapy for Parkinson's disease (PD). L-dopa-induced dyskinesia (LID) are ultimately experienced by the vast majority of patients. In addition, psychiatric conditions often manifested as compulsive behaviours, are emerging as a serious problem in the management of L-dopa therapy. The present review attempts to provide an overview of our current understanding of dyskinesia and other L-dopa-induced dysfunctions, a field that dramatically evolved in the past twenty years. In view of the extensive literature on LID, there appeared a critical need to re-frame the concepts, to highlight the most suitable models, to review the central nervous system (CNS) circuitry that may be involved, and to propose a pathophysiological framework was timely and necessary. An updated review to clarify our understanding of LID and other L-dopa-related side effects was therefore timely and necessary. This review should help in the development of novel therapeutic strategies aimed at preventing the generation of dyskinetic symptoms.
|
|
| 2. |
- Grivas, Christos, et al.
(author)
-
Generation of Multi-Gigahertz Trains of Phase-Coherent Femtosecond Laser Pulses in Ti:Sapphire Waveguides
- 2018
-
In: Laser & Photonics reviews. - : WILEY-V C H VERLAG GMBH. - 1863-8880 .- 1863-8899. ; 12:11
-
Journal article (peer-reviewed)abstract
- Miniature lasers producing ultrashort phase-coherent pulses at high repetition rates by stable mode-locking in ambient conditions can offer unique capabilities in various applications, spanning from microwave photonics to telecom and biological imaging techniques. Here, the operation of graphene mode-locked lasers based on channel waveguides written by femtosecond and picosecond laser pulses in Ti:sapphire crystals is demonstrated. Trains of pulses of 41.4 fs duration at a 21.25 GHz repetition rate are generated by capitalizing on the formation of solitons in their monolithic resonators through Gires-Tournois interferometers. The latter, allow for effective pulse shaping via tuning of the intracavity group delay dispersion while simultaneously enabling ultralow laser operating thresholds. A number of features of these sources, including their high-brightness and broad bandwidth, are essential ingredients for achieving high longitudinal resolution and sensitivity, which are the primary performance metrics of the Fourier domain/spectral domain variant of optical coherence tomography systems. A further doubling of the laser repetition rate to 42.5GHz is achieved by coherent pulse interleaving in optical fiber technology, thereby underlining the potential of the Ti:sapphire waveguide lasers to produce highly stable, wide-spaced combs of phase-coherent optical frequency lines.
|
|
| 3. |
- Sudirman, Azizahalhakim
(author)
-
Increased Functionality of Optical Fibers for Life-Science Applications
- 2014
-
Doctoral thesis (other academic/artistic)abstract
- The objective of this thesis work is to increase the functionality of optical fibers for possible applications in life-sciences. Optical fibers are a promising technology for use in biology and medicine. They are low-costwaveguides, flexible and have a small cross-section. They can guide high-power light with low loss in a micrometer core-size. These features make fibers attractive for minimally-invasive,in-vivostudies. The backwards guidance of the optical signal allows for real-time monitoring of the distance to the scattering targets and to study the environment through Raman scattering and fluorescence excitation. The longitudinal holes introduced in the fibers can be used,for instance,for delivery of medicine to a specific regionof a body. They could even be used for the extractionof species considered interesting for further analysis, for example, studyingcells that may be cancer-related.This thesis deals with four main topics. First, a demonstration is presented of the combination of high-power light guidance for ablation, low-power light reflectometry for positioning, and for liquid retrieval in a single fiber. It was found that in order to exploit the microfluidic possibilities available in optical fibers with holes, one needs to be able to combine fluids and light in a fiber without hindering the low-loss light guidance and the fluid flow. Secondly, one should also be able to couple light into the liquids and backout again. This is the subject of another paper in the present thesis. It was also observed that laser excitation through a fiber for the collection of a low-intensity fluorescence signal was often affected by the luminescence noise createdby the primary-coating of the fiber. This problem makes it difficult to measure low light-levels, for example, from single-cells. Athirdpaper in this thesis then describes a novel approach to reduce the luminescence from the polymer coating of the fiber, with the use of a nanometer-thick carbon layer on the cladding surface. Finally, exploiting some of the results described earlier, an optical fiber with longitudinal holes is used for the excitation, identification and for the collection of particles considered being of interest. The excitation light is guided in the fiber, the identification is performed by choosing the fluorescent particles with the appropriate wavelength, and, when a particle of interest is sufficiently near the fiber-tip, the suction system is activated for collection of the particle with good specificity.It is believed that the work described in this thesis could open the doors for applications in life-sciences and the future use of optical fibers for in-vivo studies.
|
|
