Global and regional emission estimates for HCFC-22

Saikawa, E.,Rigby, M.,Prinn, R. G.,Montzka, S. A.,Miller, B. R.,Kuijpers, L. J. M.,Fraser, P. J. B.,Vollmer, M. K.,Saito, T.,Yokouchi, Y.,Harth, C. M.,Mü,hle, J.,Weiss, R. F.,Salameh, P. K.,Kim, J Copernicus GmbH 2012 Atmospheric chemistry and physics Vol.12 No.21

<P>Abstract. HCFC-22 (CHClF2, chlorodifluoromethane) is an ozone-depleting substance (ODS) as well as a significant greenhouse gas (GHG). HCFC-22 has been used widely as a refrigerant fluid in cooling and air-conditioning equipment since the 1960s, and it has also served as a traditional substitute for some chlorofluorocarbons (CFCs) controlled under the Montreal Protocol. A low frequency record on tropospheric HCFC-22 since the late 1970s is available from measurements of the Southern Hemisphere Cape Grim Air Archive (CGAA) and a few Northern Hemisphere air samples (mostly from Trinidad Head) using the Advanced Global Atmospheric Gases Experiment (AGAGE) instrumentation and calibrations. Since the 1990s high-frequency, high-precision, in situ HCFC-22 measurements have been collected at these AGAGE stations. Since 1992, the Global Monitoring Division of the National Oceanic and Atmospheric Administration/Earth System Research Laboratory (NOAA/ESRL) has also collected flasks on a weekly basis from remote sites across the globe and analyzed them for a suite of halocarbons including HCFC-22. Additionally, since 2006 flasks have been collected approximately daily at a number of tower sites across the US and analyzed for halocarbons and other gases at NOAA. All results show an increase in the atmospheric mole fractions of HCFC-22, and recent data show a growth rate of approximately 4% per year, resulting in an increase in the background atmospheric mole fraction by a factor of 1.7 from 1995 to 2009. Using data on HCFC-22 consumption submitted to the United Nations Environment Programme (UNEP), as well as existing bottom-up emission estimates, we first create globally-gridded a priori HCFC-22 emissions over the 15 yr since 1995. We then use the three-dimensional chemical transport model, Model for Ozone and Related Chemical Tracers version 4 (MOZART v4), and a Bayesian inverse method to estimate global as well as regional annual emissions. Our inversion indicates that the global HCFC-22 emissions have an increasing trend between 1995 and 2009. We further find a surge in HCFC-22 emissions between 2005 and 2009 from developing countries in Asia - the largest emitting region including China and India. Globally, substantial emissions continue despite production and consumption being phased out in developed countries currently. </P>

Structure of Kähler potential for D-term inflationary attractor models

Nakayama, Kazunori,Saikawa, Ken’ichi,Terada, Takahiro,Yamaguchi, Masahide Institute of Physics Pub 2016 The journal of high energy physics Vol.2016 No.5

Efficacy of L-carnitine on ribavirin-induced hemolytic anemia in patients with hepatitis C virus infection

Shinya Sato,Kei Moriya,Masanori Furukawa,Soichiro Saikawa,Tadashi Namisaki,Mitsuteru Kitade,Hideto Kawaratani,Kosuke Kaji,Hiroaki Takaya,Naotaka Shimozato,Yasuhiko Sawada,Kenichiro Seki,Koh Kitagawa,T 대한간학회 2019 Clinical and Molecular Hepatology(대한간학회지) Vol.25 No.1

Background/Aims: L-carnitine not only alleviates hyperammonemia and reduces muscle cramps in patients with liver cirrhosis, but also improves anemia in patients with chronic hepatitis and renal dysfunction. This study prospectively evaluated the preventative efficacy of L-carnitine supplementation against hemolytic anemia during antiviral treatment using ribavirin in patients with hepatitis C virus (HCV)-related chronic liver disease. Methods: A total of 41 patients with chronic hepatitis were consecutively enrolled in this study. Group A (n=22) received sofosbuvir plus ribavirin for 3 months, whereas group B (n=19) was treated with sofosbuvir, ribavirin, and L-carnitine. Hemoglobin concentration changes, the effects of antiviral treatment, and the health status of patients were analyzed using short form-8 questionnaires. Results: A significantly smaller decrease in hemoglobin concentration was observed in group B compared to group A at every time point. Moreover, the prescribed dose intensity of ribavirin in group B was higher than that of group A, resulting in a higher ratio of sustained virological response (SVR) 24 in group B compared with group A. The physical function of patients in group B was also significantly improved compared to group A at the end of antiviral treatment. Conclusions: L-carnitine supplementation alleviates ribavirin-induced hemolytic anemia in patients with HCV and helps relieve the physical burden of treatment with ribavirin-containing regimens. These advantages significantly increase the likelihood of achieving SVR.

기상청의 통합전지구온실가스과학정보시스템 사업 소개

주상원,이해영,홍진규,이호찬,임정식,김은숙,Eri Saikawa,심창섭,정주용,김연희 한국기상학회 2021 한국기상학회 학술대회 논문집 Vol.2021 No.10

전지구적 기후위기에 대응하기 위해 우리나라는 국가적인 아젠다로 2050년까지 탄소중립을 추진하고 있다. 계획한 온실가스 감축을 달성하기 위해서는 정확하고 신속한 배출량산정이 매우 중요하다. 기존의 상향식 인벤토리는 인위적 이산화탄소 배출량에 대한 정확도는 높지만, 자연 발생 기원의 이산화탄소 및 메탄과 아산화질소 등의 배출량은 상대적으로 정확도가 낮다. 배출량의 신뢰도를 개선하기 위해서 세계기상기구(WMO) 차원에서 온실가스 배출 인벤토리의 독립적인 평가가 가능한 새로운 접근법의 필요성이 제시되었다. 제17차 세계기상기구 총회에서 통합전지구온실가스과학정보시스템(IG3IS: Integrated Global Greenhouse Gas Information System) 개발에 대한 결의안을 채택하였다. 2018년 IG³IS 실행계획을 수립하고, 회원국의 적극적인 참여를 독려하게 되었다. 또한 국가온실가스 인벤토리에 대한 IPCC TF는 2006년 국가 온실가스 IPCC 가이드라인의 2019년 개정판에 배출량 불확도를 줄이기 위한 방안으로 대기관측을 활용하는 IG3IS가 새롭게 포함하였다. 기상청 국립기상과학원은 그동안 축적된 지구대기감시와 기상모델링 역량을 바탕으로 WMO IG3IS 사업과 연계하여, INVERSE-KOREA (INvers modelling for Validating and Estimating of Reduction for Sectoral greenhouse gas Emissions in KOREA) 사업을 기획하였고, 2021년 5월 11에 아시아 최초, 세계에서는 5번째로 WMO 공식 프로젝트로 승인을 받게 되었다. INVERSE-KOREA는 국립기상과학원, 연세대학교, 서울시보건환경연구원, Emory대학과 한국환경연구원이 공동으로 참여하는 3개년 프로젝트이다. 2021년에 이산화탄소부터 적용을 시작하여, 순차적으로 메탄과 육불화황에 대한 시스템을 구축할 예정이다. 기상청 현업기상모델의 기상자료를 초기 및 경계자료로 활용하고, 10km 분해능의 WRF-DART를 주요 역모델링 시스템으로 구성하였다. GEOS-Chem과 STILT 모델을 추가로 구축하여 대기수송에 따른 불확도를 보완하고자 한다. 온실가스 관측자료는 안면도, 제주고산, 울릉도-독도 감시소를 포함한 7개 지상관측, 안면도 FTS, 위성자료와 항공기 관측자료를 자료동화할 예정이다. 21년에는 시스템을 구축하고, 22년에 성능 개선을 통해 23년에 시험운영을 추진할 계획이다. 향후 검증을 거쳐 탄소중립 추진을 위한 과학정보로 활용할 예정이다.

Efficacy of Underwater Endoscopic Mucosal Resection for Superficial Non-Ampullary Duodenal Epithelial Tumor

Masanori Furukawa,Akira Mitoro,Takahiro Ozutumi,Yukihisa Fujinaga,Keisuke Nakanishi,Koh Kitagawa,Soichiro Saikawa,Sinya Sato,Yasuhiko Sawada,Hiroaki Takaya,Kosuke Kaji,Hideto Kawaratani,Tadashi Namisa 대한소화기내시경학회 2021 Clinical Endoscopy Vol.54 No.3

Background/Aims: Endoscopic resection (ER) for superficial non-ampullary duodenal epithelial tumors (SNADETs) is challenging. Conventional endoscopic mucosal resection (CEMR) is also problematic due to the anatomical features of the duodenum. Wecompared the safety and efficacy of underwater endoscopic mucosal resection (UEMR) with those of CEMR through a retrospectiveanalysis. Methods: Altogether, 44 consecutive patients with 46 SNADETs underwent ER (18 CEMR cases and 28 UEMR cases) betweenJanuary 2016 and October 2019. We investigated the proportions of en bloc resection, R0 resection, complications, resection time,and total procedure time and compared the outcomes of patients from the CEMR group with those of patients from the UEMRgroup. Results: The median tumor size was 8.0 mm (range, 2.0–20.0 mm). The UEMR group showed a higher proportion of en blocresection (96.4% vs. 72.2%, p<0.05) and significantly lower median resection time and total procedure time (4 min vs. 9.5 min,p<0.05 and 13 min vs. 19 min, p<0.05; respectively) than the CEMR group. No complications were observed. However, two patientstreated with piecemeal resection in the CEMR group had residual tumors. Conclusions: UEMR is a feasible therapeutic option for SNADETs. It can be recommended as a standard treatment.

Bi-monthly hepatic arterial infusion chemotherapy as a novel strategy for advanced hepatocellular carcinoma in decompensated cirrhotic patients

Kei Moriya,Tadashi Namisaki,Shinya Sato,Masanori Furukawa,Akitoshi Douhara,Hideto Kawaratani,Kosuke Kaji,Naotaka Shimozato,Yasuhiko Sawada,Soichiro Saikawa,Hiroaki Takaya,Koh Kitagawa,Takemi Akahane,A 대한간학회 2019 Clinical and Molecular Hepatology(대한간학회지) Vol.25 No.4

Background/Aims: We previously reported the comparable efficacy of bi-monthly hepatic arterial infusion chemotherapy (B-HAIC) to that of sorafenib chemotherapy for the treatment of advanced hepatocellular carcinoma (aHCC) in patients with compensated cirrhosis. In this study, we demonstrate the efficacy of B-HAIC in patients with decompensated cirrhosis. Methods: Forty-five patients with aHCC refractory to transcatheter arterial chemo-embolization (TACE) were treated with B-HAIC and were divided into two groups according to hepatic functional reserve (Child-Pugh grade). Overall survival period, treatment response, and adverse events in each group were analyzed. Results: Efficacy and disease control rates in the Child-Pugh B group (n=24; 21% and 71%, respectively) were not significantly impaired compared the Child-Pugh A group (n=21; 38% and 67%, respectively). Median survival time and survival rate at 12 months in the Child-Pugh B group were 422 days and 58.3%, respectively, whereas those in the Child- Pugh A group were 567 days and 70.8%, respectively. Importantly, the hepatic functional reserve of patients did not worsen in either group during the treatment period. Furthermore, the occurrence rate of adverse events leading to discontinuation of anti-tumor treatment was not significantly increased in the Child-Pugh B group. Conclusions: Given the preservation of hepatic functional reserve afforded by B-HAIC chemotherapy in patients with decompensated cirrhosis, B-HAIC might be an acceptable alternative strategy for aHCC patients who do not respond to TACE.

Total Synthesis of Pactalactam, an Imidazolidinone-Type Pactamycin Analogue

Kim, Taejung,Matsushita, Shohei,Matsudaira, So,Doi, Tsuyoshi,Hirota, Shinji,Park, Young-Tae,Igarashi, Masayuki,Hatano, Masaki,Ikeda, Noriko,Ham, Jungyeob,Nakata, Masaya,Saikawa, Yoko THE AMERICAN CHEMICAL SOCIETY 2019 ORGANIC LETTERS Vol.21 No.10

<P>The first total synthesis of pactalactam was accomplished using substrate-controlled stereoselective aziridination and regioselective aziridine ring-opening to construct three continuous amino groups on an octasubstituted cyclopentane core. The cyclopentane framework was obtained by ring-closing metathesis and aldol coupling using a <SMALL>L</SMALL>-threonine-derived oxazoline compound. Cyclic urea formation, <I>m</I>-acetylphenyl group introduction by Chan-Lam coupling, and primary alcohol-selective acylation yielded the reported pactalactam structure. The presence of pactalactam in the fermentation broth of pactamycin-producing bacteria was also confirmed.</P> [FIG OMISSION]</BR>