4,344 research outputs found
Rayleigh Scattering Cross Section Redward of Ly by Atomic Hydrogen
We present a low energy expansion of the Kramers-Heisenberg formula for
atomic hydrogen in terms of , where and
are the angular frequencies corresponding to the Lyman limit and the incident
radiation, respectively. The leading term is proportional to
, which admits a well-known classical interpretation. With
higher order terms we achieve accuracy with errors less than 4 % of the
scattering cross sections in the region . In the
neighboring region around Ly (), we also present
an explicit expansion of the Kramers-Heisenberg formula in terms of
. The accuracy
with errors less than 4 % can be attained for with
the expansion up to the fifth order of . We expect that these
formulae will be usefully applied to the radiative transfer in high neutral
column density regions, including the Gunn-Peterson absorption troughs and
Rayleigh scattering in the atmospheres of giants.Comment: 5 pages, 2 figure
Metastatic carcinoma of the oral region : an analysis of 21 cases
Metastatic carcinoma to the jaws and oral region are very rare, representing less than 1% of all oral tumors. Unfortunately, oral metastasis is usually manifestation of an advanced stage of primary cancer, and indicates widespread disease and poor prognosis. In this retrospective study, a total of 2039 patients with history of oral malignant tumor between 1980 and 2012 at Seoul National University Dental Hospital were evaluated. We analyzed the dental and medical records, and histopathological database of 2039 patients to assess the prevalence of oral metastasis of carcinoma in terms of sex and age, as well as, the most common origin of primary cancer, and prevalent site and histopathological type of metastatic carcinoma. Among 2039 patients, 21 (1.03%) were finally diagnosed with metastatic carcinoma of the jaws and oral region. Among the 21 patients, only 11 had a working diagnosis as oral metastasis upon clinical evaluation before performing a biopsy. The mean age at the time of diagnosis with a metastatic carcinoma was 56.86, and there was a male preponderance. Metastatic carcinoma was more frequent in the jaws than in the soft tissue, especially in the mandible compared to the maxilla. The most frequent primary site was the lungs, followed by the liver and breasts. The predominant histopathological types were hepatocellular carcinoma and adenocarcinoma. Patient outcomes indicated a poor prognosis with the time from the appearance of the metastasis to death was only 12 months. According to these cases, oral metastases of carcinoma were exceedingly rare in Koreans. It can allow the clinicians take into account the possible presence of metastases and lead to early diagnosis
Topological Structure of Dense Hadronic Matter
We present a summary of work done on dense hadronic matter, based on the
Skyrme model, which provides a unified approach to high density, valid in the
large limit. In our picture, dense hadronic matter is described by the
{\em classical} soliton configuration with minimum energy for the given baryon
number density. By incorporating the meson fluctuations on such ground state we
obtain an effective Lagrangian for meson dynamics in a dense medium. Our
starting point has been the Skyrme model defined in terms of pions, thereafter
we have extended and improved the model by incorporating other degrees of
freedom such as dilaton, kaons and vector mesons.Comment: 13 pages, 8 figures, Talk given at the KIAS-APCTP Symposium in
Astro-Hadron Physics "Compact Stars: Quest for New States of Dense Matter",
November 10-14, 2003, Seoul, Korea, published by World Scientific. Based on
talk by B.-Y. Par
Renal transplantation in a patient with Bartter syndrome and glomerulosclerosis
Bartter syndrome (BS) is a clinically and genetically heterogeneous inherited renal tube disorder characterized by renal salt wasting, hypokalemic metabolic alkalosis and normotensive hyperreninemic hyperaldosteronism. There have been several case reports of BS complicated by focal segmental glomerulosclerosis (FSGS). Here, we have reported the case of a BS patient who developed FSGS and subsequent end-stage renal disease (ESRD) and provided a brief literature review. The patient presented with classic BS at 3 months of age and developed proteinuria at 7 years. Renal biopsy performed at 11 years of age revealed a FSGS perihilar variant. Hemodialysis was initiated at 11 years of age, and kidney transplantation was performed at 16 years of age. The post-transplantation course has been uneventful for more than 3 years with complete disappearance of BS without the recurrence of FSGS. Genetic study revealed a homozygous p.Trp(TGG)610Stop(TGA) mutation in the CLCNKB gene. In summary, BS may be complicated by secondary FSGS due to the adaptive response to chronic salt-losing nephropathy, and FSGS may progress to ESRD in some patients. Renal transplantation in patients with BS and ESRD results in complete remission of BS
Seasonal Prevalence of Mosquitoes, Including Vectors of Brugian Filariasis, in Southern Islands of the Republic of Korea
A survey of mosquitoes, including the vector status of Brugia malayi filariasis and their relative larval density, was conducted from 2002 to 2005 at several southern remote islands of Jeollanam-do (province), Gyeongsangnam-do, and Jeju-do, Korea, where filariasis was previously endemic. Overall, a total of 9 species belonging to 7 genera were collected. Ochlerotatus togoi (formerly known as Aedes togoi), Anopheles (Hyrcanus) group, and Culex pipiens were the predominant species captured at all areas. Oc. togoi larvae were most frequently collected at salinity levels <0.5% during June and July, with densities decreasing sharply during the rainy season in August. The most likely explanation for the eradication of filariasis in these areas is suggested to be an aggressive treatment program executed during the 1970s and the 1990s. However, high prevalence of the vector mosquitoes may constitute a potential risk for reemerging of brugian filariasis in these areas
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A Synergistic Anti-Diabetic Effect by Ginsenosides Rb1 and Rg3 through Adipogenic and Insulin Signaling Pathways in 3T3-L1 Cells
Although ginsenosides Rb1 and Rg3 have been identified as the significant ginsenosides found in red ginseng that confer anti-diabetic actions, it is unclear whether insulin-sensitizing effects are mediated by the individual compounds or by their combination. To determine the effect of ginsenosides Rb1 and Rg3 on adipocyte differentiation, 3T3-L1 preadipocytes were induced to differentiate the standard hormonal inducers in the absence or presence of ginsenosides Rb1 or Rg3. Additionally, we determined the effects of Rb1, Rg3, or their combination on the expression of genes related to adipocyte differentiation, adipogenic transcription factors, and the insulin signaling pathway in 3T3-L1 cells using semi-quantitative RT-PCR. Rb1 significantly increased the expression of CEBP alpha, PPAR gamma, and aP2 mRNAs. However, Rg3 exerted its maximal stimulatory effect on these genes at 1 mu M concentration, while a high concentration (50 mu M) showed inhibitory effects. Similarly, treatment with Rb1 and Rg3 (1 mu M) increased the expression of IRS-1, Akt, PI3K, GLUT4, and adiponectin. Importantly, co-treatment of Rb1 and Rg3 (9:1) induced the maximal expression levels of these mRNAs. Our data indicate that the anti-diabetic activity of red ginseng is, in part, mediated by synergistic actions of Rb1 and Rg3, further supporting the significance of minor Rg3
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