24 research outputs found
Clinical Characteristics of Radiation Oncology in Korea during Past 10 Years
To understand trends in the clinical characteristics of radiation oncology over the last 10 yr in Korea, annual survey questionnaires were sent to all of Korean radiation oncology facilities since 1990. Questionnaires addressed basic radiation therapy facilities and the clinical information. Responses were obtained from all facilities, and data collected from 1997 to 2006 was analyzed. The numbers of new patients that have undergone radiation therapy and the numbers of hospitals with a department of radiation oncology have steadily increased over the past 10 yr, and totaled 37,215 patients and 60 hospitals, respectively, in 2006. However, the proportion of patients irradiated among total cancer patients has remained below 30% over the last 10 yr. The numbers of prostate cancer, breast cancer, and hepatoma have increased by more than 3 fold over the past 10 yr. Moreover, the percentage of irradiated patients treated by brachytherapy was 10.3% in 1997, but this gradually fell to only 4.2% in 2006. The information collected described the role played by radiation oncology in Korea. Continuous surveys are required to enable trends to be detected
Trends for the Past 10 Years and International Comparisons of the Structure of Korean Radiation Oncology
Objective: Study aims include determination of nationwide structural characteristics of radiation oncology facilities, types of radiation therapy equipment, availability of human resources and trends and comparisons with previous surveys. Methods: An annual nationwide survey was conducted to collect the statistics of infrastructure since 1997. All requested questionnaires have been identical for 10 years. The questionnaires included status on basic radiation therapy facilities, human resources and radiation therapy equipment. Journal and statistical data reviews were performed to evaluate the structure of other countries. Results: Radiation oncology facilities have steadily increased for 10 years and reached 60 sites in 2006. Also a steady increase of 1.5 times for linear accelerators, 5.8 times for computed tomography simulators and 3.0 times for radiation treatment planning systems was noted. Meanwhile, cobalt-60 teletherapy units and hyperthermia equipment had steadily deceased for 10 years. The number of human resources has steadily increased for the past 10 years, especially for radiation therapy technologists. However, radiation therapy equipment and human resources per population are relatively low compared with advanced countries. Conclusions: This study will assist preparation of the administrative planning policy of radiation oncology and should be useful to indicate the direction of future development and educational training programs in Korea and possibly in other countries
Determination of Malignant and Invasive Predictors in Branch Duct Type Intraductal Papillary Mucinous Neoplasms of the Pancreas: A Suggested Scoring Formula
Prediction of malignancy or invasiveness of branch duct type intraductal papillary mucinous neoplasm (Br-IPMN) is difficult, and proper treatment strategy has not been well established. The authors investigated the characteristics of Br-IPMN and explored its malignancy or invasiveness predicting factors to suggest a scoring formula for predicting pathologic results. From 1994 to 2008, 237 patients who were diagnosed as Br-IPMN at 11 tertiary referral centers in Korea were retrospectively reviewed. The patients' mean age was 63.1 ± 9.2 yr. One hundred ninty-eight (83.5%) patients had nonmalignant IPMN (81 adenoma, 117 borderline atypia), and 39 (16.5%) had malignant IPMN (13 carcinoma in situ, 26 invasive carcinoma). Cyst size and mural nodule were malignancy determining factors by multivariate analysis. Elevated CEA, cyst size and mural nodule were factors determining invasiveness by multivariate analysis. Using the regression coefficient for significant predictors on multivariate analysis, we constructed a malignancy-predicting scoring formula: 22.4 (mural nodule [0 or 1]) + 0.5 (cyst size [mm]). In invasive IPMN, the formula was expressed as invasiveness-predicting score = 36.6 (mural nodule [0 or 1]) + 32.2 (elevated serum CEA [0 or 1]) + 0.6 (cyst size [mm]). Here we present a scoring formula for prediction of malignancy or invasiveness of Br-IPMN which can be used to determine a proper treatment strategy
Electrochemical Ammonia Synthesis Mediated by Titanocene Dichloride in Aqueous Electrolytes under Ambient Conditions
Under ambient conditions,
the catalytic and electrocatalytic syntheses
of ammonia from nitrogen and various proton sources including wet
tetrahydrofuran (THF) and the protic solvents methanol and water were
performed using titanocene dichloride ((η<sup>5</sup>-C<sub>5</sub>H<sub>5</sub>)<sub>2</sub>TiCl<sub>2</sub>, commonly abbreviated
to CP<sub>2</sub>TiCl<sub>2</sub>) in a two-electrode cell containing
1.0 M LiCl as the electrolyte. The highest rate of ammonia synthesis,
9.5 × 10<sup>–10</sup> mol·cm<sup>–2</sup>·sec<sup>–1</sup>·M CP<sub>2</sub>TiCl<sub>2</sub><sup>–1</sup>, was achieved at −1 V in water, whereas
the highest faradaic efficiency (0.95%) was achieved at −2
V in THF. On account of its lower Gibbs free energy, density functional
theory calculations suggest that the nitrogen-reduction reaction catalyzed
by CP<sub>2</sub>TiCl<sub>2</sub> in the presence of THF, methanol,
or water preferably occurs via the Cp<sub>2</sub>TiClN<sub>2</sub> intermediate rather than Cp<sub>2</sub>TiN<sub>2</sub>N<sub>2</sub>. Future strategies to improve both the rate of ammonia synthesis
and its faradaic efficiency must consider ways of maximizing nitrogen
selectivity to the catalytic active sites by controlling the transfer
rates of protons and/or nitrogen