scholarly journals Coordination Chemistry of a bis(tetrazine) tweezer: A Case of Host-guest Behavior With Silver Salts

2021 ◽  
Author(s):  
Cleve Dionel Mboyi ◽  
Ons Amamou ◽  
Paul Fleurat-Lessard ◽  
Julien Roger ◽  
Hélène Cattey ◽  
...  
Keyword(s):  
1H Nmr ◽  
Spectroscopic Properties ◽  
X Ray Diffraction ◽  
Visible Absorption ◽  
Face To Face ◽  
Polymeric Chains ◽  
The Face ◽  
Large Opening ◽  
Pi Interactions ◽  
Apparent Stability

The carbon-carbon cross-coupling of phenyl s-tetrazine (Tz) units at their ortho-phenyl positions allows to form constrained bis(tetrazines) with original tweezer structures. In these compounds, the face-to-face positioning of the central tetrazine cores is endorsed by pi-staking of the electron-poor nitrogen-containing heteroaromatic moieties. The resulting tetra-aromatic structure can be used as a weak coordinating ligand with cationic silver. This coordination generates a set of bis(tetrazine)‐silver(I) coordination complexes tolerating a large variety of counter anions of various geometries, namely, PF6–, BF4–, SbF6–, ClO4–, NTf2–, OTf2–. These compounds were characterized in the solid-state by single crystal XRD and reflectance spectra, and in solution by 1H NMR, mass spectrometry, electroanalysis and UV-visible absorption spectroscopy. The X-ray diffraction (XRD) structure of complexes {[Ag(3)][PF6]}∞ (4) and {[Ag(3)][SbF6]∞ (6), where 3 is 3,3'-[(1,1'-biphenyl)-2,2'-diyl]-6,6'-bis[phenyl]-1,2,4,5-tetrazine, revealed the formation of 1D polymeric chains, characterized by an evolution to a large opening of the original tweezer and a coordination of silver(I) via two chelating nitrogen atom and some C=C pi-interactions. Electrochemical and UV spectroscopic properties of the original tweezer and of the corresponding silver complex are reported and compared. 1H NMR titrations with AgNTf2 allowed to determine the stoichiometry, and apparent stability of two solution species, namely [Ag(3)]+ and [Ag(3)2]2+, that formed in CDCl3/CD3OD 2:1 v/v mixtures.

Deduction of the single-myosin-filament transforms from partially sampled layer lines in the X-ray diffraction pattern from vertebrate striated muscle

2011 ◽  
Vol 44 (2) ◽  
pp. 398-408 ◽  
Author(s):  
Kanji Oshima ◽  
Yasunobu Sugimoto ◽  
Katsuzo Wakabayashi
Keyword(s):  
Striated Muscle ◽  
Myosin Filament ◽  
Layer Line ◽  
X Ray Diffraction ◽  
Single Filament ◽  
X Ray ◽  
Patterson Function ◽  
Face To Face ◽  
Line Intensities ◽  
The Face

A novel method to correct a partial sampling effect, due to the hexagonal filament array of a statistical superlattice form, on the thick (myosin)-filament-based layer lines in X-ray diffraction patterns from higher-vertebrate striated muscle has been developed using the cylindrically averaged difference Patterson function [ΔQ(r, z)]. The method involves cutting off the inter-filament vector peaks that appear in the radial region beyond ∼32 nm on the ΔQ(r, z) map calculated from the observed layer-line intensities, and then deducing the single-myosin-filament transforms by inverse Fourier transformation of the truncated ΔQ(r, z). The accuracy of the cut-off method was tested using a single-myosin-filament model and a hexagonal filament-array model with a size of one superlattice unit cell. The layer-line intensities calculated from the truncated ΔQ(r, z) of the hexagonal filament-array model showed few sampling peaks, the layer lines being effectively coincident with those from the single-filament model except for the intensities close to the meridian. Some residual differences were caused by the face-to-face inter-crossbridge vectors between closest neighboring filaments, which correspond to ∼27.5% of the total number of crossbridge vectors in the truncated ΔQ(r, z) map, but the face-to-face inter-crossbridge vectors contributed mainly to the intensities close to the meridian. Their remnant off-meridional layer-line intensity components did not significantly affect a search for the optimum azimuthal orientation of myosin crossbridges in the resting state of muscle.

Photoluminescence profile mapping of Eu(iii) and Tb(III → IV)-embedded in quantum size SnO2 nanoparticles

RSC Advances ◽  
2014 ◽  
Vol 4 (59) ◽  
pp. 31155-31161 ◽  
Author(s):  
Young In Choi ◽  
Youngku Sohn
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Sno2 Nanoparticles ◽  
Spectroscopic Properties ◽  
X Ray Diffraction ◽  
Visible Absorption ◽  
X Ray ◽  
Quantum Size ◽  
Transmission Electron ◽  
Uv Visible

Eu(iii) and Tb(iv) activators were embedded in quantum size SnO2 nanoparticles by a hydrothermal method and their morphologies, crystal structures and spectroscopic properties were examined by transmission electron microscopy, X-ray diffraction crystallography, UV-visible absorption, and 2D/3D-photoluminescence mapping.

Supporting the Use of Rudimentary Vocalizations

2014 ◽  
Vol 23 (3) ◽  
pp. 132-139 ◽  
Author(s):  
Lauren Zubow ◽  
Richard Hurtig
Keyword(s):  
Rett Syndrome ◽  
Visual Cues ◽  
Acoustic Analysis ◽  
Eye Gaze ◽  
Research Question ◽  
Primary Research ◽  
Multiple Modalities ◽  
Face To Face ◽  
Perceptual Judgments ◽  
The Face

Children with Rett Syndrome (RS) are reported to use multiple modalities to communicate although their intentionality is often questioned (Bartolotta, Zipp, Simpkins, & Glazewski, 2011; Hetzroni & Rubin, 2006; Sigafoos et al., 2000; Sigafoos, Woodyatt, Tuckeer, Roberts-Pennell, & Pittendreigh, 2000). This paper will present results of a study analyzing the unconventional vocalizations of a child with RS. The primary research question addresses the ability of familiar and unfamiliar listeners to interpret unconventional vocalizations as “yes” or “no” responses. This paper will also address the acoustic analysis and perceptual judgments of these vocalizations. Pre-recorded isolated vocalizations of “yes” and “no” were presented to 5 listeners (mother, father, 1 unfamiliar, and 2 familiar clinicians) and the listeners were asked to rate the vocalizations as either “yes” or “no.” The ratings were compared to the original identification made by the child's mother during the face-to-face interaction from which the samples were drawn. Findings of this study suggest, in this case, the child's vocalizations were intentional and could be interpreted by familiar and unfamiliar listeners as either “yes” or “no” without contextual or visual cues. The results suggest that communication partners should be trained to attend to eye-gaze and vocalizations to ensure the child's intended choice is accurately understood.

Antecedent Factors to Recommendation Intention on the Face-to-Face Job Consulting

2013 ◽  
Vol 14 (3) ◽  
pp. 115-133
Author(s):  
조현 ◽  
Jaeshin Park ◽  
ki-jin jang
Keyword(s):  
Face To Face ◽  
The Face ◽  
Recommendation Intention

Student Perceptions of Face-to-Face and Online Discussions: The Advantage Goes To . . .

2008 ◽  
Vol 11 (4) ◽  
Author(s):  
Katrina A. Meyer
Keyword(s):  
Higher Education ◽  
Affirmative Action ◽  
Student Perceptions ◽  
Online Discussions ◽  
Political Tolerance ◽  
Self Assessment ◽  
Face To Face ◽  
The Face ◽  
Online Setting ◽  
And Gender

Thirteen students in a graduate-level course on Historical and Policy Perspectives in Higher Education held face-to-face and online discussions on five controversial topics: Diversity, Academic Freedom, Political Tolerance, Affirmative Action, and Gender. Students read materials on each topic and generated questions for discussion that were categorized by Bloom’s taxonomy so that the level of questions in the two discussion settings would be closely parallel. Upon completion of each discussion, they answered questions that addressed depth and length of the discussion, ability to remember, and a self-assessment of how the student learned. Students’ assessments show a consistent preference for the face-to-face discussion but a small number of students preferred the online setting. However, what is perhaps more interesting is a minority of approximately one-third of the students who perceived no difference between the settings, or that the two settings were perhaps complementary.

The Hierophanic Facets of the Seraphic Hymns

Trictrac ◽  
2018 ◽  
Vol 10 ◽  
Author(s):  
Petru Adrian Danciu
Keyword(s):  
Mutual Recognition ◽  
The Other ◽  
Human Being ◽  
Material World ◽  
Face To Face ◽  
The People ◽  
Musical History ◽  
The Face ◽  
The One

Starting from the cry of the seraphim in Isaiahʹ s prophecy, this article aims to follow the rhythm of the sacred harmony, transcending the symbols of the angelic world and of the divine names, to get to the face to face meeting between man and God, just as the seraphim, reflecting their existence, stand face to face. The finality of the sacred harmony is that, during the search for God inside the human being, He reveals Himself, which is the reason for the affirmation of “I Am that I Am.” Through its hypnotic cyclicality, the profane temporality has its own musicality. Its purpose is to incubate the unsuspected potencies of the beings “caught” in the material world. Due to the fact that it belongs to the aeonic time, the divine music will exceed in harmony the mechanical musicality of profane time, dilating and temporarily cancelling it. Isaiah is witness to such revelation offering access to the heavenly concert. He is witness to divine harmonies produced by two divine singers, whose musical history is presented in our article. The seraphim accompanied the chosen people after their exodus from Egypt. The cultic use of the trumpet is related to the characteristics and behaviour of the seraphim. The seraphic music does not belong to the Creator, but its lyrics speak about the presence of the Creator in two realities, a spiritual and a material one. Only the transcendence of the divine names that are sung/cried affirms a unique reality: God. The chant-cry is a divine invocation with a double aim. On the one hand, the angels and the people affirm God’s presence and call His name and, on the other, the Creator affirms His presence through the angels or in man, the one who is His image and His likeness. The divine music does not only create, it is also a means of communion, implementing the relation of man to God and, thus, God’s connection with man. It is a relation in which both filiation and paternity disappear inside the harmony of the mutual recognition produced by music, a reality much older than Adam’s language.

Agents of Practice at the Public Library’s Reference Desk

2013 ◽  
Author(s):  
Mary Cavanagh
Keyword(s):  
Public Libraries ◽  
Face To Face ◽  
Professional Boundaries ◽  
The Public ◽  
Reference Librarians ◽  
Practice Perspective ◽  
The Face ◽  
Reference Et

The face to face interactions of reference librarians and reference assistants are studied from a theoretical practice perspective. Rather than reinforcing professional boundaries, the results of this analysis support reference practice in public libraries as a highly relational activity where reference “expertise” retains a significant subjectivist, relational dimension.Les interventions en personne des bibliothèques de référence et des adjoints à la référence sont étudiées du point de vue de la pratique théorique. Plutôt que de renforcer les frontières interprofessionnelles, les résultats de cette analyse appuient l'idée que les pratiques de référence en milieu public sont des activités hautement relationnelles où l'expertise de la référence conserve une dimension subjectiviste et relationnelle. 

The Electron Effect of Aromatic Group: Control Conformation of 2-Aromatic Cyclododecanone Derivatives

2020 ◽  
Vol 24 (10) ◽  
pp. 1139-1147
Author(s):  
Yang Mingyan ◽  
Wang Daoquan ◽  
Wang Mingan
Keyword(s):  
1H Nmr ◽  
13C Nmr ◽  
Nmr Spectra ◽  
Coupling Constants ◽  
The Other ◽  
Repulsive Interaction ◽  
X Ray Diffraction ◽  
X Ray ◽  
Electron Effect ◽  
Group Control

2-Phenylcyclododecanone and 2-cyclohexylcyclododecanone derivatives were synthesized and characterized by 1H NMR, 13C NMR, HR-ESI-MS and X-ray diffraction. Their preferred conformations were analyzed by the coupling constants in the 1H NMR spectra and X-ray diffraction, which showed the skeleton ring of these derivatives containing [3333]-2-one conformation, and the phenyl groups were located at the side-exo position of [3333]-2-one conformation due to the strong π-π repulsive interaction between the π- electron of benzene ring and π-electron of carbonyl group. The cyclohexyl groups were located at the corner-syn or the side-exo position of [3333]-2-one conformation depending on the hindrance of the other substituted groups. The π-π electron effect played a crucial role in efficiently controlling the preferred conformation of 2-aromatic cyclododecanone and the other 2-aromatic macrocyclic derivatives with the similar preferred square and rectangular conformations.

Developing information literacy courses for students through virtual learning environments in Tanzania: Prospects and challenges

IFLA Journal ◽  
2021 ◽  
pp. 034003522110182
Author(s):  
Evans F Wema
Keyword(s):  
Learning Environments ◽  
Information Literacy ◽  
Teaching And Learning ◽  
Virtual Learning ◽  
Higher Learning ◽  
Virtual Learning Environments ◽  
Web Based ◽  
Face To Face ◽  
Institutions Of Higher Learning ◽  
The Face

This article reviews literature on the use of virtual learning environments by highlighting their potential and the challenges of introducing the same in Tanzania. It introduces the concept of virtual learning environments by demonstrating their applications to support teaching and learning. The article discusses the use of virtual learning environments in teaching information literacy courses by highlighting the success of using such tools in facilitating the teaching of information literacy courses to library users. In this review, special emphasis is placed on attempts by Tanzanian institutions of higher learning to introduce web-based teaching of information literacy and the challenges faced. The review reveals the need for Tanzanian institutions of higher learning to develop virtual learning environments to facilitate the teaching of information literacy courses to students and faculty so as to reach many of those who may not manage to attend the face-to-face information literacy sessions that are offered by librarians on a regular basis.

scholarly journals COVD-26. TELEPHONE CONSULTATIONS IN NEURO-ONCOLOGY DURING THE COVID-19 PANDEMIC: LEVELS OF PATIENT SATISFACTION AND COMPARISON WITH TRADITIONAL FACE-TO-FACE CONSULTATIONS

2020 ◽  
Vol 22 (Supplement_2) ◽  
pp. ii26-ii26
Author(s):  
Emma Toman ◽  
Claire Goddard ◽  
Frederick Berki ◽  
William Garratt ◽  
Teresa Scott ◽  
...  
Keyword(s):  
Patient Satisfaction ◽  
University Hospitals ◽  
Health Crisis ◽  
Patient Satisfaction Questionnaire ◽  
Telephone Consultation ◽  
Exact Test ◽  
Face To Face ◽  
Significant Difference ◽  
The Face ◽  
The University

Abstract INTRODUCTION Controversy exists as to whether telephone clinics are appropriate in neurosurgical-oncology. The COVID-19 pandemic forced neuro-oncology services worldwide to re-design and at the University Hospitals Birmingham UK, telephone clinics were quickly implemented in select patients to limit numbers of patients attending hospital. It was important to determine how these changes were perceived by patients. METHODS A 20-question patient satisfaction questionnaire was distributed to patients who attended neuro-oncology clinic in person (“face-to-face”), or via the telephone. Fisher’s exact test was used to determine significance, which was set at p< 0.05. RESULTS Eighty questionnaires were distributed between June 2020 and August 2020. Overall, 50% (n=40) of patients returned the questionnaire, 50% (n=23) of face-to-face and 50% (n=17) telephone patients. Of those who received telephone consultations, 88% (n=15) felt the consultation was convenient, 88% (n=15) were satisfied with their consultation and 18% (n=3) felt they would have preferred to have a face-to-face appointment. Of those who attended clinic in person, 96% (n=22) felt their consultation was convenient, 100% (n=23) were satisfied with their consultation and 13% (n=3) would have preferred a telephone consultation. Within the face-to-face clinic attendees, only 13% (n=3) were concerned regarding the COVID risk associated with attending hospital. There was no significant difference in patient convenience or satisfaction (p=0.565 and p=0.174 respectively) between face-to-face and telephone clinics. There was no significant difference in whether patients would’ve preferred the alternative method of consultation (p > 0.999). CONCLUSION Our study suggests that careful patient selection for neuro-oncology telephone clinic is not inferior to face-to-face clinic. Telephone clinic during COVID-19 pandemic proved to be convenient, safe and effective. This global health crisis has transformed telephone neuro-oncology consultations from an experimental innovation into established practice and should be continued beyond the pandemic in select cases.

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