3 research outputs found
The effect of selenium and zinc on CD4(+) count and opportunistic infections in HIV/AIDS patients : a randomized double blind trial
Objectives: We assessed the effect of selenium and zinc supplementation on CD4 cell count and the risk of developing opportunistic infections. Methods: In a double blind clinical trial, 146 HIV(+) patients receiving combination antiretroviral therapy with CD4(+) >200/cubic millimeter were screened for comorbidities and opportunistic infections, and randomized to receive daily selenium (200 mu g), zinc (50 mg) or placebo for 6 months, before a 3-month follow-up period. CD4 cell counts were measured in the 3(th), 6(th) and 9(th) months. The serum selenium and zinc were measured in the 6(th) month. The incidence of opportunistic infection was assessed monthly for 6 months and at the end of the 9(th) month. Results: The final incidence of supplement deficiency for placebo, zinc and selenium were 46.7%, 44.7% and 50.0%, respectively. Overall compliance with supplementation was 99.42%. Although the changes from baseline were not statistically significant, zinc supplementation was significantly associated with reduced risk of opportunistic infections. Conclusion: Development of the opportunistic infections after zinc supplementation significantly decreased; however, significant improvement in CD4 count was not observed in this group
Polycrystallinity of Lithographically Fabricated Plasmonic Nanostructures Dominates Their Acoustic Vibrational Damping
The
study of acoustic vibrations in nanoparticles provides unique
and unparalleled insight into their mechanical properties. Electron-beam
lithography of nanostructures allows precise manipulation of their
acoustic vibration frequencies through control of nanoscale morphology.
However, the dissipation of acoustic vibrations in this important
class of nanostructures has not yet been examined. Here we report,
using single-particle ultrafast transient extinction spectroscopy,
the intrinsic damping dynamics in lithographically fabricated plasmonic
nanostructures. We find that in stark contrast to chemically synthesized,
monocrystalline nanoparticles, acoustic energy dissipation in lithographically
fabricated nanostructures is solely dominated by intrinsic damping.
A quality factor of <i>Q</i> = 11.3 ± 2.5 is observed
for all 147 nanostructures, regardless of size, geometry, frequency,
surface adhesion, and mode. This result indicates that the complex
Young’s modulus of this material is independent of frequency
with its imaginary component being approximately 11 times smaller
than its real part. Substrate-mediated acoustic vibration damping
is strongly suppressed, despite strong binding between the glass substrate
and Au nanostructures. We anticipate that these results, characterizing
the optomechanical properties of lithographically fabricated metal
nanostructures, will help inform their design for applications such
as photoacoustic imaging agents, high-frequency resonators, and ultrafast
optical switches