NMR spectroscopic detection of chirality and enantiopurity in referenced systems without formation of diastereomers

Enantiomeric excess of chiral compounds is a key parameter that determines their activity or therapeutic action. The current paradigm for rapid measurement of enantiomeric excess using NMR is based on the formation of diastereomeric complexes between the chiral analyte and a chiral resolving agent, leading to (at least) two species with no symmetry relationship. Here we report an effective method of enantiomeric excess determination using a symmetrical achiral molecule as the resolving agent, which is based on the complexation with analyte (in the fast exchange regime) without the formation of diastereomers. The use of N,N′-disubstituted oxoporphyrinogen as the resolving agent makes this novel method extremely versatile, and appropriate for various chiral analytes including carboxylic acids, esters, alcohols and protected amino acids using the same achiral molecule. The model of sensing mechanism exhibits a fundamental linear response between enantiomeric excess and the observed magnitude of induced chemical shift non-equivalence in the 1H NMR spectra

Undergraduate Conductors’ and Conducting Teachers’ Perceptions of Basic Conducting Efficacy

basic conducting, nonverbal conducting behaviors, conducting effectivenessThe purpose of this study was to examine undergraduate conductors’ and conducting teachers’ perceptions about basic conducting efficacy. At the beginning and end of the semester, undergraduate students (N = 19) enrolled in a basic conducting course (a) were surveyed about the importance of certain skills necessary for being an effective conductor and (b) viewed and rated their first videotaped conducting episode. Results indicated very few significant differences in participants’ ratings of important conducting skills or their own self-evaluation of nonverbal conducting skills. In addition, university conducting teachers (N = 9) evaluated videos of 10 conductors (five who had participated in the basic conducting course and five nonconductors who had not) who led a university concert band in an identical 1-minute excerpt of band music. No significant differences were found between the basic conductors and the nonconductors’ nonverbal conducting behaviors. Implications for conducting teachers, undergraduate conducting students, and preservice teachers are discussed.YesReviewed and accepted for publication in "Update: Applications of Research in Music Education" http://upd.sagepub.com/content/early/2014/10/23/8755123314554809.abstrac

9. Februar 1917

Stadtarchiv Düsseldorf, "Tagebuch Willy Spatz" 1914-1919. 0-1-23-57.0000 Alle Scans zum Tagebucheintrag vom 9. Februar 1917 Willy Spatz (1861-1931) war Professor an der Kunstakademie Düsseldorf. Freitag, den 9. Februar. [Artikel „Der deutsche Tagesbericht.“ / Artikel „Artillerie- und Minenkampf an Cerna und Wardar.“] Man spricht jetzt schon von einer Niederlage Wilsons, da die Neutralen auf seinen Vorschlag, sich ihm gegen uns anzuschließen, nicht eingingen. Wir finden in der Zeitung zu unser..

Music education. Historical contexts and perspectives

Todas las formas de enseñanza expositiva son dirigidas por el profesor e implica proporcionar directamente la información a los alumnos. La clase magistral, la forma por excelencia de la enseñanza expositiva, se utiliza en muchos niveles de la escolarización. Son efectivas para abordar información verbal como hechos, términos, descripciones, definiciones y principios a un gran grupo. Son generalmente modos de presentación unidireccional, con una información que fluye desde el profesor hacia los estudiantes y proporcionan pocas oportunidades para que los profesores interacciones con los estudiantes o entre estudiantes. Se pueden utilizar diseños, guías de estudio, hojas de trabajo, sumarios y períodos de pregunta respuesta con el fin de generar cierta actividad e implicación en el estudiante, pero esta forma de enseñanza es insuficiente para abordar la mayoría de situaciones de aprendizaje debido a que está centrada más en lo que el profesor hace para enseñar que en lo que los estudiantes deben aprender.All forms of expository teaching are directed by the teacher and involve directly providing the information to the students. The master class, the form par excellence of expository teaching, is used at many levels of schooling. They are effective in addressing verbal information such as facts, terms, descriptions, definitions and principles to a large group. They are usually unidirectional presentation modes, with information flowing from the teacher to the students and provide few opportunities for teachers to interact with students or between students. You can use designs, study guides, worksheets, summaries and question answer periods to generate some activity and involvement in the student, but this form of teaching is insufficient to address most learning situations because Is more focused on what the teacher does to teach than what the students should learn

Enhancement of singlet oxygen generation based on incorporation of oxoporphyrinogen (OxP) into microporous solids

Singlet oxygen, 1O2, generating compounds are highly useful for photodynamic therapy or organic oxidative transformations. In this work, the synthesis and photochemical performances for singlet oxygen generation of a range of oxoporphyrinogen-containing porous coordination polymers (OxP-PCPs) are reported. Oxoporphyrinogens, a previously unreported class of singlet oxygen generators derived from the oxidation of the antioxidant-substituted porphyrin tetrakis(3,5-di-tert-butyl-4-hydroxyphenyl)porphyrin, were converted to molecular tectons by the introduction of oligophenylene-carboxylate linkers and incorporated into porous coordination polymers using well-known oxo-Zr(IV)6 cluster chemistry. Their structures and textural properties were analyzed revealing substantial surface areas up to 650 m2 g−1 for the optimum linker length (biphenylyl). The oxoporphyrinogen precursors exhibit good quantum yields of singlet oxygen generation (up to Φ = 0.37), and a high level of activity is maintained in the resulting coordination polymers, which appear to be superior for singlet oxygen generation to the precursors and to a reported reference material. These OxP-PCP materials were applied for the selective oxidation of sulfides to sulfoxides. This work demonstrates that the excellent singlet oxygen generator oxoporphyrinogens can be successfully incorporated as porous solids and conveniently applied in heterogeneous oxidative transformations