334 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
Analyse des phospholipides oxydés par LC (ESI) -MSMS
No full textLes phospholipides (PLs) sont des molécules biologiques complexes, de structures très variées et représentent une classe de métabolites d’intérêt pour l’étude des relations entre l’alimentation et le développement des maladies métaboliques. Cette classe de composés peut donner lieu à la formation d’un grand nombre de produits d’oxydation. Ainsi, les phospholipides oxydés (PLs-Ox) sont de plus en plus reconnus non seulement comme des marqueurs de stress oxydant, mais aussi des marqueurs de différentes pathologies associées à l’inflammation, telles que l’athérosclérose et le diabète. Cependant, très peu d’informations sont actuellement disponibles dans les bases de données pour identifier ces molécules, du fait de leur disponibilité commerciale limitée.
L’objectif de ce travail était d’acquérir des nouvelles connaissances sur les PLs-Ox afin de proposer une stratégie analytique pour leur analyse. Notre approche lipidomique s’est basée sur une méthode de profilage par LC-MS/MS d’un extrait de lipides totaux plasmatiques, associée à un workflow d’aide à l’identification des PLs implémenté dans la plateforme web Galaxy W4M (http://workflow4metabolomics.org).
Au cours de ce travail, une méthode de synthèse des PLs-Ox a tout d’abord été mise en place à partir des Phosphatidylcholines (PCs) ayant des longueurs de chaines différentes, des degrés et une position des insaturations différentes.
Une méthode d’analyse par spectrométrie de masse (Qtrap 5500 Sciex) équipé avec une source d’ionisation electrospray a ensuite été développée pour caractériser des produits d’oxydation. Un couplage avec la chromatographie liquide par Injection en Flux Continu (FIA) a permis la mise au point de la méthode LC-MS pour pouvoir, par la suite, réaliser la séparation chromatographique des formes oxydés. La cinétique de formation des produits d’auto-oxydations a été étudiée.
Les premiers résultats obtenus montrent une grande diversité des produits d’oxydation à chaînes longues et/ou à chaînes courtes raccourcies. Il a été observé que la formation des produits d’oxydation était dépendante de la structure des PLs, le rapport de formes oxydées variant au cours du temps.
Ces résultats permettent d’envisager la mise en place d’une stratégie d’analyse lipidomique de ces composés, et l’enrichissement des bases de données existante
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]
Leave for Appeal: Departure as a Requirement for Review of Deportation Orders
No full textIn this Article, Mr. Spiro addresses the congressional amendments to the Immigration Naturalization Act meant to combat the legal maneuvers calculated to defeat the execution of deportation orders. The addition of section 106 was meant to prohibit all appeals of deportation orders under which an alien had already departed the United States. The author analyzes the legislative history of the provision and notes that Congress intended to the departure rule to apply even in more egregious cases of INS misbehavior. The author discusses federal circuit law and finds that neither the rule nor its exception best serve the dual objectives of deterring manipulative delay while affording fairness to aliens seeking to challenge the finality of their deportation. To combat the filing of frivolous appeals, the author recommends amending section 106 so that deportation appeals be permitted only from abroad
Mammon and Medicine
No full textThe author raises the question of whether physicians should disclose
the stakes they have as researchers in persuading their patients to
participate in clinical trials. In the course of giving informed consent,
patients are rarely told that their doctors may have strong financial and
professional interests in recruiting them as subjects, that pharmaceutical
companies and the National Institutes of Health pay research centers and
physicians well for completed patient studies, and that professional
advancement and distinction depend on the amount of research done. Spiro
believes controlled clinical trials are valuable, but argues that full
disclosure of the benefits that physicians expect to achieve from their
patients' willingness to serve as subjects will enhance the latters' freedom
to decide on participation. (KIE abstract
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