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Understanding enzymatic Diels-Alder (DA) reactions that can form complex natural product scaffolds is of considerable interest. Sch 210972 1, a potential anti-HIV fungal natural product, contains a decalin core that is proposed to form through a DA reaction. We identified the gene cluster responsible for the biosynthesis of 1 and heterologously reconstituted the biosynthetic pathway in Aspergillus nidulans to characterize the enzymes involved. Most notably, deletion of cghA resulted in a loss of stereoselective decalin core formation, yielding both an endo (1) and a diastereomeric exo adduct of the proposed DA reaction. Complementation with cghA restored the sole formation of 1. Density functional theory computation of the proposed DA reaction provided a plausible explanation of the observed pattern of product formation. Based on our study, we propose that lipocalin-like CghA is responsible for the stereoselective intramolecular [4+2] cycloaddition that forms the decalin core of 1.

Numerous studies have investigated the kinds of verbs that can be used with there constructions. Generally, only existence and appearance verbs can occur in there constructions. However, some cases have been observed involving verbs not lexically expressing existence or appearance. This study focuses on there sentences with the verb become which are noteworthy in the following two respects. First, although the verb become is not an existence or appearance verb but a change-of-state verb, the verb is felicitously used with there constructions. Second, become is used without an adjectival or nominal complement, a unique argument realization pattern of the verb not found in other syntactic contexts. This study, based on a detailed examination of actual data in corpora, claims that there sentences with become express the appearance/occurrence of an entity. Although the postverbal noun is structurally a subject in there constructions and the subject of the verb become is usually interpreted as an entity undergoing a change, the postverbal noun of there sentences with become is an entity that has arisen as a result of the changing event. [ABSTRACT FROM AUTHOR]

Postoperative cognitive dysfunction (POCD) is a serious complication of anesthesia and surgery, and the major risk factor of POCD is aging. Although the exact pathophysiology of POCD remains unknown, two possible and reliable mechanisms have been proposed: neuroinflammation and neurodegeneration, i.e., amyloid [beta] accumulation and/or tau protein phosphorylation, by surgery and/or general anesthetics. White matter lesions (WML) are produced by chronic cerebral hypoperfusion, frequently observed in elderly people, and closely related to cognitive decline. As recent studies have revealed that WML are a significant risk factor for POCD in humans, and we previously also demonstrated that persistent hypocapnea or hypotension caused neuronal damage in the caudoputamen or the hippocampus in a rat model of chronic cerebral hypoperfusion, which features global cerebral WML without neuronal damage and is recognized as a good model of human vascular dementia especially in elderly people, we hypothesize that in addition to those two previously proposed mechanisms, perioperative vital sign changes that cause reductions in cerebral blood flow might contribute to POCD in patients with WML, whose cerebral blood flow is already considerably decreased., Author(s): Shinichi Nakao [sup.1] , Tomohisa Yamamoto [sup.1] , Seishi Kimura [sup.1] , Takashi Mino [sup.1] , Tatsushige Iwamoto [sup.1] Author Affiliations: (Aff1) 0000 0004 1936 9967, grid.258622.9, Department of [...]

Since 2000, and especially during the United Nations Decade of Education for Sustainable Development (DESD 2005-2014), many universities have begun offering educational programmes on sustainability. Over this span, the level and type of diversity among students have only increased. This begs the question: How does university student diversity affect sustainability education? What is productive and confounding about learners' cultural and academic heterogeneity? This research draws on a literature review, a survey of university students studying sustainability in Japan and an observational study. The results demonstrate that interaction between students from different cultures and disciplines clearly improves skills for sustainability education, especially critical thinking and problem solving. Moreover, the surveyed students expressed interest in and appreciation of opportunities to expose their sustainability research themes to audiences of various research fields.

1,2,4-Triazole and 1,2,4-triazoline are important components of bioactive molecules and catalysts employed in organic synthesis. Therefore, the efficient synthesis of these components has received significant research attention. However, studies on their structural diversity remain lacking. Previously, we developed chiral phase-transfer-catalyzed asymmetric reactions of α-imino carbonyl compounds with α,β-unsaturated carbonyl compounds and haloalkanes. In this study, we demonstrate the formal [3 + 2] cycloaddition reaction of α-imino esters with azo compounds under Brønsted base catalysis, resulting in the corresponding 1,2,4-triazolines in high yields. The results revealed that a wide range of substrates and reactants can be applied, irrespective of their steric and electronic characteristics. The present reaction made the general preparation of 3-aryl pentasubstituted 1,2,4-triazolines possible for the first time. Furthermore, a mechanistic study suggested that the reaction proceeds without isomerization into the aldimine form. [ABSTRACT FROM AUTHOR]