| 1. |
|
|
| 2. |
- Anderson, Albert M, et al.
(author)
-
Cognitive and Neuronal Link With Inflammation: A Longitudinal Study in People With and Without HIV Infection.
- 2020
-
In: Journal of acquired immune deficiency syndromes. - 1944-7884. ; 85:5, s. 617-625
-
Journal article (peer-reviewed)abstract
- Across many settings, lack of virologic control remains common in people with HIV (PWH) because of late presentation and lack of retention in care. This contributes to neuronal damage and neurocognitive impairment, which remains prevalent. More evidence is needed to understand these outcomes in both PWH and people without HIV (PWOH).We recruited PWH initiating antiretroviral therapy and PWOH at 2 sites in the United States. One hundred eight adults were enrolled (56 PWOH and 52 PWH), most of whom had a second assessment at least 24 weeks later (193 total assessments). Tumor necrosis factor alpha, monocyte chemotactic protein-1 (MCP-1), neopterin, soluble CD14, and neurofilament light chain protein (NFL) were measured in plasma and cerebrospinal fluid (CSF). Using multivariate models including Bayesian model averaging, we analyzed factors associated with global neuropsychological performance (NPT-9) and CSF NFL at baseline and over time.At baseline, higher CSF MCP-1 and plasma sCD14 were associated with worse NPT-9 in PWH, while CSF HIV RNA decrease was the only marker associated with improved NPT-9 over time. Among PWH, higher CSF neopterin was most closely associated with higher NFL. Among PWOH, higher CSF MCP-1 was most closely associated with higher NFL. After antiretroviral therapy initiation, decrease in CSF MCP-1 was most closely associated with NFL decrease.Monocyte-associated CSF biomarkers are highly associated with neuronal damage in both PWH and PWOH. More research is needed to evaluate whether therapies targeting monocyte-associated inflammation may ameliorate HIV-associated neurobehavioral diseases.
|
|
| 3. |
- Fokine, Michael, 1970-, et al.
(author)
-
Spectral features of specular reflection from nanoparticle films
- 2010
-
In: Physica Status Solidi. C, Current topics in solid state physics. - : Wiley. - 1610-1634 .- 1610-1642. ; 8:9, s. 2673-2675
-
Journal article (peer-reviewed)abstract
- In this work we analyze the internal reflection (Fresnel reflection) from Au nanoparticles on the end face of optical fibers. We demonstrate that changes in the refractive index of the surrounding medium can be detected by shifts in the reflection spectra associated with changes in the Localized Surface Plasmon Resonance of the Au-Nanoparticles. The spectral response is simulated using a model based on the interference in multilayer structures and can be described by transfer-matrix method.
|
|
| 4. |
- Gouvêa, P. M. P., et al.
(author)
-
Characterization of a fiber optic sensor based on LSPR and specular reflection
- 2010
-
In: Optical Sensors (Sensors) 2010. - 9781557528964
-
Conference paper (peer-reviewed)abstract
- A fiber optic sensor based on Localized Surface Plasmon Resonance (LSPR) and specular reflection has been characterized as a function of refractive índex. The sensitivity has been obtained for the range from n=1.0 to n=2.0.
|
|
| 5. |
- Gouvea, Paula M. P., et al.
(author)
-
Internal specular reflection from nanoparticle layers on the end face of optical fibers
- 2011
-
In: Journal of Applied Physics. - : AIP Publishing. - 0021-8979 .- 1089-7550. ; 109:10, s. 103114-
-
Journal article (peer-reviewed)abstract
- Metal nanoparticles deposited on a dielectric substrate exhibit an absorption peak due to localized surface plasmon resonance (LSPR). Changes in the refractive index of the surrounding medium cause the LSPR band to shift in wavelength. In this paper, gold nanoparticles were placed on the end face of an optical fiber spliced to a reflection setup. As expected in reflection geometries, the back-reflected signal exhibits a dip at wavelengths in the LSPR band when the fiber tip is surrounded by ambient air (n = 1). However, as the refractive index of the surrounding medium is increased, there is a gradual inversion from a dip (n = 1.0) to a peak (n = 2.0). To explain these results, a model based on absorption and interference between the specular reflections from the fiber/nanoparticle and nanoparticle/ambient interfaces is proposed, showing that our reflection configuration can be used in sensing applications.
|
|
| 6. |
- Jang, Hoon, et al.
(author)
-
Control of forward stimulated polariton scattering in periodically-poled KTP crystals
- 2013
-
In: Optics Express. - 1094-4087. ; 21:22, s. 27277-27283
-
Journal article (peer-reviewed)abstract
- We report suppression of forward stimulated polariton scattering (SPS) in chi((2)) structured media. Periodic poling in KTiOPO4 (KTP) leads to the destructive interference of phonon-polariton waves, which is responsible for the dependence of the SPS threshold on the poling period. This was confirmed by comparing the SPS thresholds in periodically-poled KTP (PPKTP) crystals with different poling periods. Further confirming the physical picture, we studied the changes in the Stokes power distribution as a function of the rotation angle of the PPKTP crystal.
|
|
| 7. |
- Jang, Hoon, et al.
(author)
-
Control of forward stimulated polariton scattering in periodically poled nonlinear crystals
- 2012
-
In: 2012 Conference on Lasers and Electro-Optics, CLEO 2012. - Washington, D.C. : IEEE. - 9781467318396 ; , s. 6325627-
-
Conference paper (peer-reviewed)abstract
- Periodic poling in KTP leads to periodic phase reversal of the polaritons generated in Cherenkov phase-matched direction. This is responsible for the dependence of stimulated Raman scattering threshold on crystal rotation angle and poling period.
|
|
| 8. |
- Jang, Hoon, et al.
(author)
-
Counter-propagating parametric interaction with phonon-polaritons in periodically poled KTiOPO4
- 2017
-
In: Optics Express. - : Optical Society of America. - 1094-4087. ; 25:3, s. 2677-2686
-
Journal article (peer-reviewed)abstract
- Strongly enhanced backward stimulated polariton scattering (BSPS) is demonstrated in periodically-poled KTiOPO4 (KTP) crystals with a high power-conversion efficiency up to 70%. We study the physical mechanism of such counter-propagating parametric interaction with phonon-polaritons in χ(2) modulated structures. BSPS is a three-wave mixing that is distinguished from backward stimulated Raman scattering (BSRS), while a strong absorption at large polariton wave-vectors can still make BSPS display certain characteristics of BSRS such as self-compression of the Stokes pulse. We also compare BSPS with counter-propagating parametric oscillation in the near- and mid-infrared range, providing an estimation of the fabrication error margin to expect the outcome of their competition in the same device.
|
|
| 9. |
|
|
| 10. |
- Jang, Hoon, et al.
(author)
-
Highly efficient backward stimulated polariton scattering in periodically poled KTiOPO4
- 2015
-
In: CLEO: Science and Innovations 2015.
-
Conference paper (peer-reviewed)abstract
- X(2)-nonlinearity enhanced by crystal lattice contribution in the THz-region is behind backward stimulated polariton scattering with efficiencies exceeding 50% in PPKTP where forward scattering process is suppressed. 10-times compression of counter-propagating signal is observed.
|
|
