Theoretical study on ultrafast intersystem crossing of chromium(III) acetylacetonate

In the relaxation process from the ^4T_[2g] state of chromium(III) acetylacetonate, Cr^III(acac)_3, ultrafast intersystem crossing (ISC) competes with vibrational relaxation (VR). This contradicts the conventional cascade model, where ISC rates are slower than VR ones. We hence investigate the relaxation process with quantum chemical calculations and excited-state wavepacket simulations to obtain clues about the origins of the ultrafast ISC. It is found that a potential energy curve of the ^4T_[2g] state crosses those of the ^2T_[1g] states near the Franck–Condon region and their spin–orbit couplings are strong. Consequently, ultrafast ISC between these states is observed in the wavepacket simulation

A quantum chemical model for a series of self-assembled nanocages: the origin of stability behind the coordination-driven formation of transition metal complexes up to [M₁₂L₂₄]²⁴⁺

Herein, we present a systematic computational model to study the electronic states and free energies of a self-assembled multi-metal complex series. By combining the previously developed model Hamiltonian approach for transition-metal complexes and the generalized Born model, the thermodynamics, optimized geometries, and electronic states of the [Pd12L24]24+ nanocage are revealed, together with [PdnLm]2n+ complex series. The effective model Hamiltonian is a theoretical method to obtain the d-electron wavefunction and potential energy including interaction energy between the transition-metal and ligands. In the present improvement, the electronic state on each transition-metal center is focused as a building unit and solved under the whole electronic field of the assembling system. We realize a reliable and systematic treatment of multi-transition-metal complexes with different sizes and charges. Consequently, our model could reproduce binding energies of the [PdnLm]2n+ complex series quantitatively as compared to density functional theory (DFT). Regarding free energy, we revealed that the assembling solute becomes unstable due to the electrostatic interaction, and effects of the solvent and counter anions mainly compensated it. Optimized geometries were also analysed. The local square-planar coordination structures around the palladium centres were characterized in the complex series. The relationships between the entire symmetrical geometries and the local coordination structures are also discussed. Finally, electronic structures of the [Pd12L24]24+ nanocage were well characterized as a single-determinant, where only dx2−y2 is unoccupied due to the ligand-field effect. We also found that the solvent polarized the electronic states of the Pd ions, whereas the counter anion suppressed the polarization. The present method realizes size-independent reliable and rapid computations, and therefore can be expected to further application studies on self-assembly dynamics

ソウキ イガン ガ ゲンイン ト カンガエラレタ キュウセイ イ ホウカシキエン ノ 1レイ

This paper describes a case of acute phlegmonous gastritis due to early gastric cancer diagnosed by the gastroendoscopic findings, the intraoperative findings and the histological diagnosis. A 58-year-old man presented with fever, nausea, vomiting and rapidly progressive upper abdominal pain. Gsatrofiberscopy showed remarkable redness and mucosal edema on the distal half portion of the stomach, and the ulcerated lesion in the antrum. We operated him emergently as suspected perforation of the stomach, and found the stomach swelling on the middle body to the antrum with remarkable wall thickness and redness under the laparotomy. Distal gastrectomy was performed on the diagnosis of acute phlegmonous gastritis. Histopathologic examination disclosed that the ulcerated lesion in the antrum was the early gastric cancer, 2.0×1.5cm, well-differentiated adenocarcinoma. The antrum around it had the thickest wall with severe inflammation including neutrophilic infiltration and microabcess, which was also observed to the middle body, although less severe. Acute phlegmonous gastritis is a nonspecific supprant inflammation that is as uncommon as only 111 cases described in the Japanese literature, including the present case. The pathogenesis is still unclear, although predisposing factors like mucosal injury, achlorhydria and immunocompromised state have been mentioned

ショクドウガン ジュツゴ ニ メチシリン タイセイ ヒョウヒ ブドウキュウキン ニヨル ハイエン オ ガッペイ シタ 1レイ

Methicilin-resistant Staphylococcus aureus (MRSA) is well known as the causative agent in severe infections, but we had recognized methicilin-resistant Staphylococcus epidermidis(MRSE) was not the pathogen. However, MRSE has become to be caused of serious infectious diseases to compromised hosts. A case of severe pneumonia after esophagectomy due to MRSE is reported.A 60 year-old man underwent an esophagectomy for esophageal cancer. During artificial ventilation, on the 6th postoperative day, high fever and leucocytosis were observed, and chest X-P showed severe pneumonia. A tracheotomy was performed and only MRSE was isolated from the sputum. Vancomycin and minocycline were used intravenously. The pneumonia improved gradually and the respirator removed on the 20th postoperative day. MRSE is considered less pathogenic than MRSA, but it is necessary that MRSE is recognized one of the important causes of severe infection after major operations

Mutations in nuclear pore complex promote osmotolerance in Arabidopsis by suppressing the nuclear translocation of ACQOS and its osmotically induced immunity

We have previously reported a wide variation in salt tolerance among Arabidopsis thaliana accessions and identified ACQOS, encoding a nucleotide-binding leucine-rich repeat (NLR) protein, as the causal gene responsible for the disturbance of acquired osmotolerance induced after mild salt stress. ACQOS is conserved among Arabidopsis osmosensitive accessions, including Col-0. In response to osmotic stress, it induces detrimental autoimmunity, resulting in suppression of osmotolerance, but how ACQOS triggers autoimmunity remains unclear. Here, we screened acquired osmotolerance (aot) mutants from EMS-mutagenized Col-0 seeds and isolated the aot19 mutant. In comparison with the wild type (WT), this mutant had acquired osmotolerance and decreased expression levels of pathogenesis-related genes. It had a mutation in a splicing acceptor site in NUCLEOPORIN 85 (NUP85), which encodes a component of the nuclear pore complex. A mutant with a T-DNA insertion in NUP85 acquired osmotolerance similar to aot19. The WT gene complemented the osmotolerant phenotype of aot19. We evaluated the acquired osmotolerance of five nup mutants of outer-ring NUPs and found that nup96, nup107, and aot19/nup85, but not nup43 or nup133, showed acquired osmotolerance. We examined the subcellular localization of the GFP–ACQOS protein and found that its nuclear translocation in response to osmotic stress was suppressed in aot19. We suggest that NUP85 is essential for the nuclear translocation of ACQOS, and the loss-of-function mutation of NUP85 results in acquired osmotolerance by suppressing ACQOS-induced autoimmunity in response to osmotic stress

ヨウエキナイ ニ オケル ブンシ ダイナミックス ノ リロンテキ ケンキュウ

京都大学0048新制・課程博士博士(理学)甲第11335号理博第2893号新制||理||1432(附属図書館)22978UT51-2005-D86京都大学大学院理学研究科化学専攻(主査)教授 加藤 重樹, 教授 寺嶋 正秀, 教授 谷村 吉隆学位規則第4条第1項該当Doctor of ScienceKyoto UniversityDA

Ultrafast Electronic Relaxation in Aqueous [Fe(bpy)3]^2+: A Surface Hopping Study

Trajectory surface hopping simulations are performed to better understand the electronic relaxation dynamics of [Fe(bpy)3]^2+ in aqueous solution. Specifically, the ultrafast relaxation from the photoexcited singlet metal-to-ligand charge-transfer (MLCT) to the metastable quintet metal-centered (MC) states is simulated through the surface hopping method, where the MLCT and MC states of [Fe(bpy)3]^2+ in aqueous solution are computed by using a model electronic Hamiltonian developed previously. As a result, most of the trajectories are interpreted to show the sequential relaxation pathways via the triplet MC states, though some are the direct pathway from MLCT to the quintet MC states. Even though the triplet MC states are involved in the relaxation, the population transfer to the singlet MC ground state is very small, and the population of the quintet MC states reaches more than ∼96%, reasonably consistent with the unity quantum efficiency discussed experimentally