There have been several studies supporting a possible relationship between high suicide rate and high altitude. However socioeconomic status may confound this association because low socioeconomic status, which is known to be related to a high suicide rate, is also associated with living at high altitude. This study aims to explore whether the relationship between high altitude and high suicide rate remains after adjusting for socioeconomic status in South Korea. We collected demographic data of completed suicides, the mean altitude of the district where each suicide took place, and the mean income of each district. We analyzed the data using regression analysis before and after adjustment for mean income. We found that there is a positive correlation between altitude and suicide rate, even after adjustment for mean income. Thus, altitude appears to be an independent risk factor for suicide.

A new chromium(III) complex (2) with a readily available aminotriphenolate ligand (L tBu,tBu ) was developed as an efficient catalyst for alternating ring-opening copolymerization of cyclic epoxides and anhydrides to afford polyesters. The single-crystal structure of 2 exhibits an octahedral geometry despite the high steric profile of L tBu,tBu . After the reaction conditions were optimized, complex 2 in the presence of a cocatalyst produced perfectly alternating polyesters with high molecular weights (up to M n = 44.2 kg/mol) and low dispersity at high conversion. In addition, various polyesters prepared using combinations of comonomers exhibited relatively high glass transition temperatures.

Purpose: Overall 5-year survival rates for colon and rectal cancer reported recently by the American Cancer Society were 89%, 90% for localized disease, 71%, 71% for regional disease, and 14%, 15% for distant disease. But the results of survival rate of colorectal cancer in a single institution were very rare. The aim of this study is to evaluate surgical results and survival rates of colorectal cancer. Methods: We conducted a retrospective study with patients who underwent curative resection for a primary colorectal adenocarcinoma between 2009 and 2018. Results: Five-year overall and disease-free survival were 79.5% and 69.9%, respectively. The overall 5-year survival by stages was 94.7% in stage I, 88.4% in stage II, 74.3% in stage III and 31.5% in stage IV. Five-year disease-free survival was 91% in stage I, 79.8% in stage II, 63.3% in stage III, and 18.9% in stage IV. The overall 5-year survival in rectal cancer was superior to colon cancer (P=0.014) while there was no difference in 5-year disease-free survival (P=0.338). Overall survival in female patients was better than male patient (P=0.029). Overall survival by age was worst in group of less than 40 years old (62.5%), and best in group between 41 and 65 years old (86.5%). Postoperative mortality within 30 days was 0.4%, and the recurrence rate was 19.2%. Conclusion: With the development of surgical skills and various treatments, postoperative outcome of colorectal cancer is expected to improve. It may be helpful for surgeons to improve their surgical outcomes when they review their data and conduct active researches.

Two air-stable organic radicals derived from oxalyl chloride and cAAC were synthesized, resulting in the unexpected formation of a known (amino)(carboxy) radical cation ([2]BF4) and the oxidative formation of a 1,2-dicarbonyl radical cation ([3]BF4) from a neutral 3-oxetanone compound (4). The highly strained and newly discovered 4 was obtained by a single-electron reduction of [3]BF4 with a mild reducing agent. This result differs from the generation of NHC-based 1,2-dicarbonyl radicals, indicating the uniqueness of cAAC.