Effect of the blend ratio of cyclic and linear polyethylene blends on isothermal crystallization in the quiescent state

The role of entanglements that form between cyclic and linear polymers in crystallization is of particular interest, but it is not fully understood. We investigated the crystallization behaviors of blends of cyclic polyethylene (C-PE) and linear polyethylene (L-PE) in a quiescent state to elucidate the role of this novel entanglement in crystallization. The samples were prepared by mixing the prepared C-PE and L-PE specimens at L-PE weight fraction (ΦL-PE) values of 0–100 wt%, with the weight average molecular weights of C-PE and L-PE being 175 × 103 and 154 × 103, respectively. The isothermal crystallization behaviors were analyzed through polarizing optical microscopy (POM) and differential scanning calorimetry (DSC). The morphology observed through POM was similar to that of ΦL-PE. From the time evolution of the heat flow measured via DSC, we obtained the half-crystallization time (t1/2) values as functions of ΦL-PE at different degrees of supercooling (ΔT). The 1/t1/2 values of the C-PE and L-PE homopolymers were approximately the same at ΔT = 25.5 and 26.5 K. At a larger ΔT value, the 1/t1/2 value of C-PE was significantly larger than that of L-PE. In contrast, 1/t1/2 reached a minimum value at ΦL-PE = 30–40 wt%, irrespective of ΔT. As the entanglement density increased with increasing ΦL-PE, the crystallization rate was expected to decrease monotonically. By considering the experimental relationship between 1/t1/2 and ΦL-PE, we speculated that the suppression of crystallization in the blended system was caused by a novel entanglement formed by the penetration of the L-PE chain into the C-PE chain

A novel homozygous variant of the thrombomodulin gene causes a hereditary bleeding disorder

ArticleBlood Advances. 5(19): 3830-3838 (2021)journal articl

Hadron-Hadron Interactions from Imaginary-time Nambu-Bethe-Salpeter Wave Function on the Lattice

Imaginary-time Nambu-Bethe-Salpeter (NBS) wave function is introduced to extend our previous approach for hadron-hadron interactions on the lattice. Scattering states of hadrons with different energies encoded in the NBS wave-function are utilized to extract non-local hadron-hadron potential. "The ground state saturation", which is commonly used in lattice QCD but is hard to be achieved for multi-baryons, is not required. We demonstrate that the present method works efficiently for the nucleon-nucleon interaction (the potential and the phase shift) in the 1S_0 channel.Comment: 13 pages, 6 figure

Tomato root-associated Sphingobium harbors genes for catabolizing toxic steroidal glycoalkaloids

トマト根に定着する細菌からトマトの毒を分解する酵素を発見 --土壌微生物が植物の分泌する有害成分を解毒するメカニズムの理解に貢献--. 京都大学プレスリリース. 2023-10-02.Roots of Bloody Mary. Tomato root-associated Sphingobium harbors genes for neutralizing toxic compound. 京都大学プレスリリース. 2023-10-06.Plant roots exude various organic compounds, including plant specialized metabolites (PSMs), into the rhizosphere. The secreted PSMs enrich specific microbial taxa to shape the rhizosphere microbiome, which is crucial for the healthy growth of the host plants. PSMs often exhibit biological activities; in turn, some microorganisms possess the capability to either resist or detoxify them. Saponins are structurally diverse triterpene-type PSMs that are mainly produced by angiosperms. They are generally considered as plant defense compounds. We have revealed that α-tomatine, a steroid-type saponin secreted from tomato (Solanum lycopersicum) roots, increases the abundance of Sphingobium bacteria. To elucidate the mechanisms underlying the α-tomatine-mediated enrichment of Sphingobium, we isolated Sphingobium spp. from tomato roots and characterized their saponin-catabolizing abilities. We obtained the whole-genome sequence of Sphingobium sp. RC1, which degrades steroid-type saponins but not oleanane-type ones, and performed a gene cluster analysis together with a transcriptome analysis of α-tomatine degradation. The in vitro characterization of candidate genes identified six enzymes that hydrolyzed the different sugar moieties of steroid-type saponins at different positions. In addition, the enzymes involved in the early steps of the degradation of sapogenins (i.e., aglycones of saponins) were identified, suggesting that orthologs of the known bacterial steroid catabolic enzymes can metabolize sapogenins. Furthermore, a comparative genomic analysis revealed that the saponin-degrading enzymes were present exclusively in certain strains of Sphingobium spp., most of which were isolated from tomato roots or α-tomatine-treated soil. Taken together, these results suggest a catabolic pathway for highly bioactive steroid-type saponins in the rhizosphere

Beached Whales : Examining Japan\u27s Rejection of an International Norm (""2004 ISS-OUP Prise"" Winning Article)

国際規範に関する分析は概して,システムレベルの規範の普及に着目している.本稿では,そのような分析はネオリアリズム,新自由主義制度派,構造主義などに根ざしており,主に二つの問題があると主張する.一つは,それらの分析が普及に成功した規範の実例に多大な関心を払っているのに対し,失敗したものについては見過ごしていることである.もう一つの問題はそれらの分析が,規範の普及する過程において国際規範と国内構造がどのように関連しているかを検証できていないことである.この関連を見過ごすことにより,システムレベルの研究は国際規範が国内の領域に広がる具体的なメカニズムとプロセスを明らかにできないでいる.本稿は国内構造(特に文化・政治的構造)が国内レベルにおける国際規範の普及を可能にする主要要素であると主張する.日本における反捕鯨規範の受け入れ拒否を分析するにあたり本稿は,このような国内構造が反捕鯨規範の出現や受け入れを阻むフィルターとして機能していると論じるものである.Much of the analysis of international norms has focused on norm diffusion at the systemic level. This study argues that such analyses based on neorealism, neoliberal institutionalism, and constructivism have two major shortcomings. One is that they pay much attention to successful cases of norm diffusion, but neglect failed ones. The other is that they fail to examine the linkage between international norms and domestic structures in the processes of norm diffusion. By neglecting this linkage, systemic-level studies cannot clarify specific mechanisms and process through which international norms reach the domestic arena. This study stresses that domestic structures, in particular cultural and political structures, are the key factors allowing international norm diffusion at the domestic level. Analyzing Japan\u27s refusal to accept an antiwhaling norm, this paper argues that these domestic structures have served as filters to block the emergence and acceptance of this norm in Japan