Diffusion and activation of n-type dopants in germanium

The diffusion and activation of $n$-type impurities (P and As) implanted into $p$-type Ge(100) substrates were examined under various dose and annealing conditions. The secondary ion mass spectrometry profiles of chemical concentrations indicated the existence of a sufficiently high number of impurities with increasing implanted doses. However, spreading resistance probe profiles of electrical concentrations showed electrical concentration saturation in spite of increasing doses and indicated poor activation of As relative to P in Ge. The relationships between the chemical and electrical concentrations of P in Ge and Si were calculated, taking into account the effect of incomplete ionization. The results indicated that the activation of P was almost the same in Ge and Si. The activation ratios obtained experimentally were similar to the calculated values, implying insufficient degeneration of Ge. The profiles of P in Ge substrates with and without damage generated by Ge ion implantation were compared, and it was clarified that the damage that may compensate the activated $n$-type dopants has no relationship with the activation of P in Ge.Comment: 6 pages, 4 figure

Complementary and alternative medical therapy utilization by people with chronic fatiguing illnesses in the United States

<p>Abstract</p> <p>Background</p> <p>Chronic fatiguing illnesses, including chronic fatigue syndrome (CFS), pose a diagnostic and therapeutic challenge. Previous clinical reports addressed the utilization of health care provided to patients with CFS by a variety of practitioners with other than allopathic training, but did not examine the spectrum of complementary and alternative medicine (CAM) therapies used. This study was designed to measure CAM therapy use by persons with fatiguing illnesses in the United States population.</p> <p>Methods</p> <p>During a random-digit dialing survey to estimate the prevalence of CFS-like illness in urban and rural populations from different geographic regions of the United States, we queried the utilization of CAM including manipulation or body-based therapies, alternative medical systems, mind-body, biologically-based, and energy modalities.</p> <p>Results</p> <p>Four hundred forty fatigued and 444 non-fatigued persons from 2,728 households completed screening. Fatigued subjects included 53 persons with prolonged fatigue, 338 with chronic fatigue, and 49 with CFS-like illness. Mind-body therapy (primarily personal prayer and prayer by others) was the most frequently used CAM across all groups. Among women, there was a significant trend of increasing overall CAM use across all subgroups (p-trend = 0.003). All categories of CAM use were associated with significantly poorer physical health scores, and all but one (alternative medicine systems) were associated with significantly poorer mental health scores. People with CFS-like illness were significantly more likely to use body-based therapy (chiropractic and massage) than non-fatigued participants (OR = 2.52, CI = 1.32, 4.82). Use of body-based therapies increased significantly in a linear trend across subgroups of non-fatigued, prolonged fatigued, chronic fatigued, and CFS-like subjects (p-trend = 0.002). People with chronic fatigue were also significantly more likely to use body-based therapy (OR = 1.52, CI = 1.07, 2.16) and mind-body (excluding prayer) therapy than non-fatigued participants (OR = 1.73, CI = 1.20 – 2.48).</p> <p>Conclusion</p> <p>Utilization of CAM was common in fatiguing illnesses, and was largely accounted for by the presence of underlying conditions and poor physical and mental health. Compared to non-fatigued persons, those with CFS-like illness or chronic fatigue were most likely to use body-based and mind-body therapies. These observations have important implications for provider education programs and development of intervention strategies for CFS.</p

Residual order within thermally grown amorphous SiO2 on crystalline silicon

The origin of x-ray diffraction peaks observed on the crystal truncation rods (CTR’s) in reciprocal space for thermally grown SiO_2 films has been investigated by large-scale atomistic simulation of silicon oxidation. Three models of SiO_2 on Si(001), Si(111), and Si(113) were formed by introducing oxygen atoms in crystalline Si from the surfaces in an atom-by-atom manner. The SiO_2 structures are classified as being amorphous in conventional characterizations, but retain the residual order originating from the {111} atomic planes in their parent crystals. The calculated diffraction patterns exhibit intensity peaks with Laue-function-like fringe profiles along the CTR’s, at positions depending on the substrate orientations, agreeing quite well with experimental results.K. Tatsumura, T. Watanabe, D. Yamasaki, T. Shimura, M. Umeno and I. Ohdomari. Residual order within thermally grown amorphous SiO_2 on crystalline silicon. Physical Review B, 2004, 69(8), 085212. https://doi.org/10.1103/PhysRevB.69.085212. Copyright 2004 by the American Physical Society

Reactions and diffusion of atomic and molecular oxygen in the SiO2 network

To address the reactions and diffusion of atomic and molecular oxygen in SiO_2, the modification of the SiO_2 network on exposure to an atomic or molecular oxygen atmosphere is investigated by measuring the x-ray-diffraction profile of the residual order peak emanating from the oxide. Analyses of the peak intensity and its fringe pattern provide experimental evidence for the recent theoretical predictions, indicating that atomic oxygen is incorporated into the SiO_2 network near the surface and diffuses toward the interface along with modifying it even at a low temperature of 400°C, whereas molecular oxygen diffuses without reacting with the bulk SiO_2 even at a temperature of 850°C that is sufficiently high for oxidation reaction at the interface.Tatsumura K., Shimura T., Mishima E., et al. Reactions and diffusion of atomic and molecular oxygen in the SiO_2 network. Physical Review B - Condensed Matter and Materials Physics, 2005, 72(4), 045205. https://doi.org/10.1103/PhysRevB.72.045205. Copyright 2005 by the American Physical Society

Ethnic differences in choices of health information by cancer patients using complementary and alternative medicine: an exploratory study with correspondence analysis

This study examined patterns in the use of health information among Caucasian, Japanese, and non-Japanese Asian Pacific Islander cancer patients in Hawaii and explored the relation of ethnicity and educational level to choices of health information sources. Information from 140 cancer patients, most of whom were users of complementary and alternative medicine (CAM), was analyzed using correspondence analysis. Three clusters of health information pertinent to the three ethnic groups emerged from the data. The results of this study revealed that Caucasian patients preferred objective, scientific, and updated information obtained through medical journals or newsletters from research institutions, telephone information services, and the internet. Japanese patients relied on media and commercial sources including television, newspapers, books, magazines and CAM providers. Non-Japanese Asians and Pacific Islanders used information sources involving person-to-person communication with their physicians, social groups, and other cancer patients. A higher educational level was closely related to a cluster of health information stressing objective, scientific and updated information, while a lower educational level was associated with interpersonally communicated information. The three ethnicity-specific patterns of health information use remained relatively stable at different educational levels, implying that the effect of patients' ethnicity overrides their educational level in shaping their choices of health information. The results of this study indicate the importance of recognizing cancer patients' culturally developed world views when understanding their health information-seeking behavior. For medical practice, these findings indicate the need for healthcare providers to assist cancer patients to obtain accurate health information in a culturally sensitive way.Cancer Health information Ethnicity Complementary medicine Japanese-Americans Asians Pacific Islanders