388 research outputs found
An existence theorem for stationary discs in almost complex manifolds
No full textAbstractAn existence theorem for stationary discs of strongly pseudo-convex domains in almost complex manifolds is proved. More precisely, it is shown that, for all points of a suitable neighborhood of the boundary and for any vector belonging to certain open subsets of the tangent spaces, there exists a unique stationary disc passing through that point and tangent to the given vector. This result gives a generalization of a theorem of B. Coupet, H. Gaussier and the second author, originally proved only for almost complex structures which are small deformations of an integrable one
How the Ji’kmaqn Came to Spiro: Possible Additions to the Inventory of Sound-Making Instruments Depicted in the Spiro Engravings
No full textWhile doing research on turtle shell rattles the author stumbled onto a photograph of a rare and unusual idiophone whose exact likeness appears twice in one of the engraved shell images from Spiro. This paper describes the instrument and the Spiro image and discusses how an instrument currently found only in the Maritime Provinces of Canada may have come to be portrayed on a marine shell cup found at Spiro
Polycyclic Spiro Lignans and Biphenyl Tetrahydrofuranone Lignans from Gymnotheca involucrata
No full textFour rare polycyclic spiro lignans (1-4) and four new biphenyl tetrahydrofuranone lignans (5-8) were isolated from the whole plant of Gymnotheca involucrata. The structures of the new compounds were elucidated on the basis of detailed spectroscopic analysis and the absolute configuration of 1 was confirmed by single crystal X-ray diffraction. Bioassay results showed that compounds 2 and 6 exhibited weak antifungal activity against Uromyces viciae-fabae at 100 ppm in leaf-disc assays, while compound 3 demonstrated moderate insecticidal activity against Diabrotica balteata at 500 ppm in an artificial diet assay
Synthesis of spiro[4.4]nonane-containing functional organic molecules
No full textSpiro[4.4]nonane features are an important scaffold in many applications such as enantioenriched ligands, functional materials, natural products, and polymers. Excited by the prospect of the spiro[4.4]nonane scaffold, its structural intricacy still appears challenging in chemical synthesis. Many functional organic molecules possessing spiro[4.4]nonane scaffold(s) have recently been reported and synthesized. We provide a Minireview highlighting such advancements and discuss the future opportunities of spiro[4.4]nonane scaffolds in organic chemistry. Representative examples from 2019 to 2024 are discussed. © 2024 The Author
Organocopper(III) Spiro Complexes: Synthesis, Structural Characterization, and Redox Transformation
No full textReductive elimination of Cu(III) intermediates is often proposed as a key step in many copper catalyzed or-mediated formation of or C-heteroatom bonds. However, there still lacks concrete evidence on this key :step, mainly because Cu(III) complexes are usually too unstable to be isolated and structurally characterized. In this work, novel organocopper(III) spiro complexes and their analogons organocopper(I) spiro complexes were synthesiied and structurally characterized. Single-crystal X-ray structural analysis revealed that the spiro Cu(III) atom adopted a distorted square-planar geometry while its corresponding, spiro Cu(I) atom was tetrahedrally coordinated. A redox transformation between these spiro Cu(I) and Cu(Ill) complexes was experimentally observed by reacting with reductants or oxidants, respectively. As concrete evidence, the organocopper(III) spiro compounds were found to form C-C bonds intramolecularly via reductive elimination.National Natural Science Foundation of China [21372012, 21690061]SCI(E)ARTICLE3913688-1369113
Jugenderinnerungen aus Hessischen Judengemeinden.
No full textSalomon Spiro's grandfather, a student at the Yeshiva of Rabbi Seckel Wormser, was a well-respected Jewish scholar and teacher at a Jewish elementary school. His son, Salomon's father, followed him in this position. Description of rural Jewish life in Northern Hesse. Recollections of the celebration of Jewish festivals and rituals. Antisemitism of the environment. The author describes the difficult relationship with his father due to his ambition to have his son become a Jewish scholar. Reinforced Jewish education. Brief career in the synagogue chorus and as an auxiliary cantor. Salomon attended the humanistic high school (Gymnasium) in Hersfeld, a town known for the antisemitic attitudes of its inhabitants. Incidents of discrimination and assaults at school. Strict observance of Jewish rites under the supervision of the leading rabbi in the Jewish community of Fulda. Opposition to Zionist activities. After graduation in 1904 Salomon Spiro attended the Breuer Yeshiva of the Frankfurt "Austrittsgemeinde". He quit his studies at the yeshiva after a short time due to the strict orthodox environment and its intolerance of liberal developments. Beginnings of university studies in Wuerzburg.Salomon Spiro was born in Schenklengsfeld (Hessen) in 1885 to a family of Jewish teachers. He briefly attended the orthodox Breuer Yeshiva in Frankfurt am Main.Synopsis in fileFuldaWuerzburgAntisemitismHolidays, JewishJewish communitiesJews, liturgy and ritualUniversities and collegesYeshiva (Frankfurt am Main)Spiro, Salomon Bae
Effects of heteroatom substitution in spiro-bifluorene hole transport materials
No full textThree new spirofluorene-based hole transport materials, Spiro-S, Spiro-N, and Spiro-E, are synthesized by replacing the para-methoxy substituent in 2,2',7,7'-tetrakis(N,N-di-p-methoxyphenylamine)-9,9'-spirobifluorene (Spiro-MeOTAD) with methylsulfanyl, N,N-dimethylamino and ethyl groups. Their properties as hole transport materials in perovskite solar cells are investigated. The impact of replacing the para-methoxy substituent on bulk properties, such as the photophysical properties, HOMO/LUMO energy level, hole extraction properties and morphologies of perovskite thin films are investigated. Their optoelectronic and charge-transport properties and performance in perovskite solar cells are compared with the current benchmarked and structurally-related hole transport material (HTM) Spiro-MeOTAD. Surprisingly, the methylsulfanyl substituted spirofluorene shows the highest power conversion efficiency of 15.92% among the investigated spirofluorenes, which is an over 38% increase in PCE compared with that of Spiro-MeOTAD under similar device fabrication conditions.Shenzhen Science and Technology Research Grant [JCYJ20140509093817690]; Shenzhen Key Laboratory of Organic Optoelectromagnetic Functional Materials of Shenzhen Science and Technology Plan [ZDSYS20140509094114164]; Shenzhen Peacock Program [KQTD2014062714543296]; Nanshan Innovation Agency Grant [KC2015ZDYF0016A]; Guangdong Key Research Project [2014B090914003, 2015B090914002]; National Basic Research Program of China (973 Program) [2015CB856505]SCI(E)[email protected]
Staging of Lung Cancer
No full textinfo:eu-repo/semantics/publishedThoracic Malignancies, S.G. Spiro, R.M. Huber and S.M. Jane
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