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A study was conducted to characterize time-resolved differential reflections in InAs(sub x)P(sub 1-x)/InP strained-multiple-quantum wells. The evolution of the differential reflection dynamics was analyzed based on changes in the refractive index and cap absorption. Results indicated that carrier diffusion in the cap layer and barriers support a critical role in differential reflection dynamics.

To assess a proper dose for radiation therapy fitting the typical physical characteristics of male Korean bodies, a mathematical phantom was prepared based on standard Korean male measurements. Upon brachytherapy of prostate cancer by implanting 192Ir into the prostate gland (the source organ), the absorbed dose of the prostate gland and surrounding organs and the expected dose of people within the vicinity were assessed. 192Ir, which has been the radionuclide of choice for prostate cancer brachytherapy, was selected for the simulation. It was assumed that 1 Ci of initial radioactivity would be administered. As a result, 1.28E-02 Gy/Ci was exhibited in the prostate gland of the source organ, and the dose to which persons within the vicinity were exposed was exhibited to be 9.19E-06 Sv at a distance of 30 cm from the front. [ABSTRACT FROM PUBLISHER]

The authors have developed a mathematical model for calculating internal radionuclide dosimetry for the Korean Reference Adult Male, and have also derived paired-organ and other selected inter-organ photon-specific absorbed fractions for this model. Each lung, kidney and adrenal gland was set as a separate source region even though each of them shares an identical physiological function with their complementary half. The thyroid gland was also set as a source region. Specific absorbed fractions (SAFs) were then derived by selecting 10 photon energies from 0.02 to 4.0 MeV inclusive. For this purpose the Monte Carlo methodology was used, and the derived SAF was compared with the resulting value of MIRD Pamphlet No. 5 and ORNL TM-8381, both of which were derived on the basis of the ICRP-23 reference man. The comparison showed that MIRD No. 5 and ORNL TM-8381 resulted in a higher absorbed fraction, but the phantom created on the basis of the Korean reference man led to a higher SAF. The weight of the organs of the phantom, and the size and location of the trunk seem to account for the differences. The energy-dependent differences in the SAFs are considered to be related to the distance between the source and target regions, the composition of the intervening tissues, and the photon energies and mean free paths. Also, as a result of deriving SAFs after setting each separate lung, kidney and adrenal gland as a source region, it was found that, although they are of the same physiological function, each individual organ serves as a source region on its own. Differences were noted in SAFs exerted on the source and target organs in accordance with the location of the organs, that is, whether they were located to the left or right of the source organs. The SAF derived in this study can be used for a more accurate internal radionuclide dosimetry for Koreans and other Orientals whose physiology, lifestyle and dietary habits are similar to those of Koreans. [ABSTRACT FROM AUTHOR]

Abstract Background Korea saw a sharp increase in HIV diagnosis from 2000. This serious public health concern must be monitored diligently. We identified the characteristics and trends in HIV prevalence among visitors to public health centers (PHCs) from 2000 to 2009. Methods We retrieved ten-year data of HIV tests from 253 PHCs. The HIV prevalence was analyzed by gender, age, nationality, region, and reason for HIV testing. Data were analyzed using logistic regression and score test for trend. Results HIV prevalence among PHCs’ visitors has rapidly increased for six years since 2000, decreased from 2006, and then remained stable. Approximately 50% of total HIV tests were performed for sexually transmitted infection risk group (STI RG), who were tested 1.4 times within a year. Women and the 20s comprised approximately 70% and 40% of PHCs’ visitors, respectively. The prevalence of voluntary test takers was the highest and showed most rapid increase (P = 0.007), but that of prisoners declined (P = 0.003). The prevalence of STI RG was lower than those of the other groups and remained stable throughout the ten-year period (P = 0.606). Percentage of anonymous tests was 2–3% of a total HIV tests, but overall HIV-positive rate showed a rapid increase (P Conclusions As voluntary or anonymous testing groups are actively engaged in learning their status of HIV, these groups showed the highest in HIV infection. Groups in the population with these characteristics should be located and encouraged to be tested, and offered anonymity. This study suggests that it is important to ascertain the characteristics of people choosing to take voluntary testing.