APL Nameplate
  • Volume/Page
  • Keyword
  • DOI
  • Citation
  • Advanced
   
 
 
 

Flickr Twitter iResearch App Facebook

BROWSE VOLUMES

Year Range: 
Search Issue | RSS Feeds RSS
Previous Issue Next Issue

8 Feb 1999

Volume 74, Issue 6, pp. 777-892

Return to All Sections
back to top
RSS Feeds

Noninvasive absorption and scattering spectroscopy of bulk diffusive media: An application to the optical characterization of human breast

R. Cubeddu, A. Pifferi, P. Taroni, A. Torricelli, and G. Valentini

Appl. Phys. Lett. 74, 874 (1999); http://dx.doi.org/10.1063/1.123395 (3 pages) | Cited 34 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
A time-resolved reflectance and transmittance spectrophotometer was developed and used to evaluate noninvasively and simultaneously the absorption and transport scattering spectra of bulk turbid media. The experimental setup, based on mode-locked dye and titanium:sapphire lasers and on an electronic chain for time-correlated single photon counting, was fully automated to make in vivo measurements on biological tissues feasible. The optical characterization of breast, of interest for the development of optical mammography, was performed in vivo on a wide spectral range (610–1010 nm). In particular, the absorption spectral features of the main tissue components (hemoglobin, water, and lipids) were recognized with different relative weight, depending on the age and the measurement position. Best fit with the absorption spectra of the main constituents was performed to evaluate their relative concentration in tissues. © 1999 American Institute of Physics.
Show PACS
87.64.K- Spectroscopy
87.63.L- Visual imaging
87.64.Cc Scattering of visible, uv, and infrared radiation
42.62.Be Biological and medical applications

Abiotic synthesis of amino acids by x-ray irradiation of simple inorganic gases

Jun-ichi Takahashi, Teruo Hosokawa, Hitomi Masuda, Takeo Kaneko, Kensei Kobayashi, Takeshi Saito, and Yuichi Utsumi

Appl. Phys. Lett. 74, 877 (1999); http://dx.doi.org/10.1063/1.123396 (3 pages) | Cited 13 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
1–2 keV x-ray irradiation was carried out using a synchrotron radiation source on simulated primitive earth environment: a gas mixture of carbon monoxide, nitrogen, and water at atmospheric pressure. High-speed liquid chromatography of the hydrolyzed product solution detected amino acids. The amount of amino acids increased with the total energy absorbed by the gas molecules, and the antipodal optical isomers were generated in almost equal quantities. These imply that the precursors for amino acids were produced through x-ray-induced photolysis of inorganic molecules followed by recombination and polymerization into bio-organic compounds. These results suggest that prebiotic formation of amino acids is possible in primitive earth atmosphere by x ray as well as cosmic ray. © 1999 American Institute of Physics.
Show PACS
82.50.Kx Processes caused by X-rays or γ-rays
82.80.Bg Chromatography
87.15.R- Reactions and kinetics
Return to All Sections
Close

Google Calendar

ADVERTISEMENT

Go to AIP Home   © AIP Publishing LLC
close