420 research outputs found
Results of Hepatectomy for Hepatocellular Carcinoma at the National Cancer Center Hospital
The number of hepatectomies has increased greatly in recent years. Surgery for hepatocellular
carcinoma (HCC) in the normal liver has not increased. However, the increase in numbers of
hepatectomies for HCC associated with liver cirrhosis is remarkable. More than 80% of our hepatectomy
cases were cirrhotic and about 80% of these cirrhotic cases had HCCs 5cm or less in diameter. The
operative mortality rate has improved in the latter half of this series, from 10.1% (9/89) to 1.5% (5/338),
in spite of an increase in cases with poor liver function. This corresponds to a decrease in the mean value
of the annual operative blood loss. The survival rates after hepatectomy for all cases (n = 378) were
40.6% ± 6.6 (% ± SE) for 5 year and 22.7% ± 5.3 for 10 year at the end of 1988. A difference of the
5-year survival rate between the patients operated on before 1981 (n = 78, 25.6% ± 4.9) and after 1982
(n = 300, 46.1% ± 4.8) was observed (p<0.05). Because the cancer-free survival rates of the patients
operated on in the two periods, before 1981 and after 1982, were almost the same, the recent
improvement of the survival rates seems to be due to a prolongation of survival time after recurrence
Vegetation development on the glacier moraines in Oobloyah Valley, Ellesmere Island high arctic Canada
The process of the vegetation development on glacier moraines was surveyed in the lower stream area of Oobloyah Valley (80°50\u27N, 82°45\u27W), Ellesmere Island, high arctic Canada. Four glacier moraines, and an outwash plane with different establishment periods in the proglacial field of Arklio Glacier, were surveyed .The oldest moraine was estimated to have been established during the Full Glacial, ca. 25000-35000 years ago, and the youngest one during the Little Ice Age, ca. 250 years ago. The vegetation properties such as number of species per study plot, cover of vegetation, lichens and bryophytes showed constant increase the moraine age, suggesting directional vegetation development. Changes in the species composition were such that new species successively appeared during the establishment of the moraines without obvious replacement of the species. It was concluded that the manner of the vegetation development was directional-nonreplacement succession even under extreme high arctic environment, differing from the generally accepted view that under an extreme high arctic environment nondirectional-nonreplacement succession prevails. Vegetation physiognomy approached Cassiope tetragona-dominated dwarf shrub heath, which generally prevails in more southern regions than Ellesmere Island. The period required for the vegetation development in the study area was assumed to be quite long, probably at least ca. 20000 years
センソウ ノ ムジンカ ガ センソウ リンリ ニ モタラス エイキョウ ニツイテ ノ コウサツ
本稿では、近年めざましい勢いで進んでいる軍事における「ロボット」の活用(戦争の無人化)が、国際人道法や武力紛争法など既存の制度の中で示されている戦争倫理にどのような影響を及ぼしているのかを考察する。人間のように考え振る舞うロボットは、従来は SF 映画やアニメの世界での架空の存在に過ぎなかった。しかしながら、近年その存在が現実になりつつある。単に人間が戦場に行くことなく軍事活動が行なえる兵器というだけでなく、自律的に判断を行い、敵への攻撃を開始することができる兵器(Lethal Autonomous Weapons Systems: LAWS=自律型致死性兵器システム)が登場しつつある。このような人間に近づいたロボットが兵器として戦場に現れた時、どのような新たな倫理上の問題(あるいは既存の問題の深刻化)が生じるのかを考え、論点を整理し分析する
ヒコッカ シュタイ ケンキュウ カラ ミタ フンソウ カイケツガク ト アンゼン ホショウガク ノ セッテン
本稿は、非国家主体研究の系譜と現状に焦点を当てることで、紛争解決学と安全保障学の相互補完的な関係の可能性を模索することを目的としている。イラクやアフガニスタンなどで懸案となっている国家建設を支援する存在としても、またそれを妨げ秩序を攪乱する存在としても、非国家主体はその存在感を高めている。マクロな視点から国際秩序の維持に関心を持つ安全保障学では、9.11テロ事件で国際秩序を攪乱し得るほどの力を持つ国際テロ組織が現れたことで、非国家主体を相手とする対テロ戦争が主要な研究テーマとなった。他方、ミクロな視点から現地住民のニーズに焦点を当て、秩序攪乱者を生み出す土壌の変化を促すことを目的とし、隔離・排除・制圧の対象としてだけではなく、包摂し得る対象としても非国家主体に目を向けてきた。こうした異なる視点から同じ非国家主体を見てきた二つの研究の間で、双方の知見を補完的に活用する方法を模索する
ハイブリッド ナ コッカ ケンセツ ノ カノウセイ ト カダイ イラク ノ チアン ブモン カイカク SSR オ レイ トシテ
本稿では、紛争国における国家再建において、民主化と自由主義経済を重視する欧米主導のリベラルな国家建設と、現地の被支援国政府および現地住民の主体性を重視するローカル・オーナーシップ論の融合の事例としてイラクの治安部門改革(SSR:security sector reform)、すなわち国家の中枢に位置する治安維持を担う様々な組織、例えば軍、警察、司法機関等の実務能力の向上や民主的な組織への体質改善を目指して行われる種々の改革を扱う。欧米諸国を中心とする支援国が目指す国家像と、現地国の政府や住民が望む国家像との間に齟齬が存在した場合、どのような折衷的な国家建設が可能なのかを、イラクで実際に行われている取り組みをもとに分析する。現地アクターと外部アクターが協働する「ハイブリッド」な国家建設の可能性と課題をまとめる
コウキョウセイ ノ イミ ノ ヘンカ ト グンジ ノ ミンエイカ
本稿では、従来は正規軍が担ってきた軍事活動の中核部分に至るまで民間企業(民間軍事会社:PMSC)に委託されるようになっている現実の背景には、活動の公的領域と私的領域の境界線についての認識(公共性認識)が変容していることがあると論じる。国内における「行政」と「公共」のズレの拡大を論じる議論を援用し、そうしたズレが平和構築の分野にも反映されていることを指摘する。その結果として、あらゆる公的活動を公的主体のみによって担うことはもはやできなくなっており、ますます多くの民間部門の行為主体が、かつては公的主体(政府や国際機関など)のみが行うべきと考えられていた活動を担うようになってきていることを示す。そしてそうした公的主体と民間主体の協働が、軍事の分野にも確実に広がっていることを示す例として、PMSCの事例を実証的に見ていく
Selected Mutations in a Mesophilic Cytochrome c Confer the Stability of a Thermophilic Counterpart
Mesophilic cytochrome c551 of Pseudomonas aeruginosa (PA c551) became as stable as its thermophilic counterpart, Hydrogenobacter thermophilus cytochrome c552 (HT c552), through only five amino acid substitutions. The five residues, distributed in three spatially separated regions, were selected and mutated with reference to the corresponding residues in HT c552 through careful structure comparison. Thermodynamic analysis indicated that the stability of the quintuple mutant of PA c551 could be partly attained through an enthalpic factor. The solution structure of the mutant showed that, as in HT c552, there were tighter side chain packings in the mutated regions. Furthermore, the mutant had an increased total accessible surface area, resulting in great negative hydration free energy. Our results provide a novel example of protein stabilization in that limited amino acid substitutions can confer the overall stability of a natural highly thermophilic protein upon a mesophilic molecule.This work was supported by a grant from the Japanese Ministry of Education, Science and Culture
Lokiarchaeota archaeon schizorhodopsin-2 (LaSzR2) is an inward proton pump displaying a characteristic feature of acid-induced spectral blue-shift
The photoreactive protein rhodopsin is widespread in microorganisms and has a variety of photobiological functions. Recently, a novel phylogenetically distinctive group named 'schizorhodopsin (SzR)' has been identified as an inward proton pump. We performed functional and spectroscopic studies on an uncharacterised schizorhodopsin from the phylum Lokiarchaeota archaeon. The protein, LaSzR2, having an all-trans-retinal chromophore, showed inward proton pump activity with an absorption maximum at 549 nm. The pH titration experiments revealed that the protonated Schiff base of the retinal chromophore (Lys188, pK(a)=12.3) is stabilised by the deprotonated counterion (presumably Asp184, pK(a)=3.7). The flash-photolysis experiments revealed the presence of two photointermediates, K and M. A proton was released and uptaken from bulk solution upon the formation and decay of the M intermediate. During the M-decay, the Schiff base was reprotonated by the proton from a proton donating residue (presumably Asp172). These properties were compared with other inward (SzRs and xenorhodopsins, XeRs) and outward proton pumps. Notably, LaSzR2 showed acid-induced spectral 'blue-shift' due to the protonation of the counterion, whereas outward proton pumps showed opposite shifts (red-shifts). Thus, we can distinguish between inward and outward proton pumps by the direction of the acid-induced spectral shift
A blue-shifted anion channelrhodopsin from the Colpodellida alga Vitrella brassicaformis
Microbial rhodopsins, a family of photoreceptive membrane proteins containing the chromophore retinal, show a variety of light-dependent molecular functions. Channelrhodopsins work as light-gated ion channels and are widely utilized for optogenetics, which is a method for controlling neural activities by light. Since two cation channelrhodopsins were identified from the chlorophyte alga Chlamydomonas reinhardtii, recent advances in genomic research have revealed a wide variety of channelrhodopsins including anion channelrhodopsins (ACRs), describing their highly diversified molecular properties (e.g., spectral sensitivity, kinetics and ion selectivity). Here, we report two channelrhodopsin-like rhodopsins from the Colpodellida alga Vitrella brassicaformis, which are phylogenetically distinct from the known channelrhodopsins. Spectroscopic and electrophysiological analyses indicated that these rhodopsins are green- and blue-sensitive pigments (lambda(max) = similar to 550 and similar to 440 nm) that exhibit light-dependent ion channeling activities. Detailed electrophysiological analysis revealed that one of them works as a monovalent anion (Cl-, Br- and NO3-) channel and we named it V. brassicaformis anion channelrhodopsin-2, VbACR2. Importantly, the absorption maximum of VbACR2 (similar to 440 nm) is blue-shifted among the known ACRs. Thus, we identified the new blue-shifted ACR, which leads to the expansion of the molecular diversity of ACRs
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