118 research outputs found
Crystal structure, Hirshfeld surface and spectroscopic studies of the noncentrosymmetric Bi(III) halide complex: [C8H12N]3BiCl6
No full textA new organic–inorganic hybrid material with the formula [C8H12N]3BiCl6 has been synthesized and characterized by spectroscopic techniques and single crystal X-ray structure determination. This compound crystallizes in the non-centrosymmetric space group Pna21 of the orthorhombic system with crystallographic parameters a = 25.5620(2), b = 16.7170(5), c = 7.8840(4) Å, V = 3369.0(2) Å3 and Z = 4. Its structure consists of discrete [BiCl6]3− anions, showing the distorted octahedral geometry, surrounded by three crystallographically independent 2-phenylethylammonium cations. The crystal packing is governed by the formation of a number of N–H⋯Cl hydrogen bonds arranged in a three-dimensional network. Crystal structure analysis supported with the Hirshfeld surface and fingerprint plots enabled the identification of the significant intermolecular interactions. The 13C and 15N CP-MAS NMR spectra are in agreement with the X-ray structure. The optical properties of [C8H12N]3BiCl6 were investigated by UV–Vis and luminescence spectroscopy. The differential scanning calorimetry (DSC) revealed that the title compound is stable up to 210 °C
Crystal structure, vibrational and optical properties of a new Bi(III) halide complex: [C6H16N2]5Bi2Br10(BiBr6)2·2H2O
No full textA new Bi(III) halide complex, [C6H16N2]5Bi2Br10(BiBr6)2·2H2O has been synthesized at room temperature in the presence of 1,4-dimethylpiperazine by slow evaporation technique and characterized by physicochemical methods. It crystallizes in a triclinic centrosymmetric space group, P-1. The crystal lattice is composed of two types of anionic entities [Bi2Br10]4â and [BiBr6]3â surrounded by 1,4-dimethylpiperazine-1,4-diium cations and water molecules. The anionic part was found for the first time in halobismuthate(III) solid complexes. In the crystal, the components are linked by C-Hâ¦Br(Ow) and Ow-Hâ¦Br hydrogen bonds to built three-dimensional network. The vibrational absorption bands were identified by Infrared and Raman spectroscopy. The 13C and 15N CP-MAS NMR spectra are in agreement with the X-ray structure. Intermolecular hydrogen bonding was investigated by means of the Hirshfeld surfaces. The percentages of hydrogen bonding interactions are analyzed by Fingerprint plots of Hirshfeld surface. The optical properties of this compound were studied by UVâVis and luminescence spectroscopy. The DSC curve shows that this compound is stable below melting point
Structural, vibrational, optical properties and theoretical studies of new noncentrosymmetric material: Bis(2-Amino-5-(methylthio)-1,3,4-thiadiazol-3-ium) pentachloroantimonate
No full textA new non-centrosymmetric Sb(III) halide complex with formula (C3H6N3S2)(2)SbCl5 (complex 1) has been synthesized by reaction between antimony trioxide (Sb2O3) and 2-Amino-5-(methylthio)-1,3,4-thiadiazole (AMT,) in an aqueous solution of hydrochloric acid. Single crystal X-ray diffraction analysis shows that this compound crystallizes in orthorhombic system with the non-centrosymmetric space group Pna2(1). Its crystal structure consists of isolated (C3H6N3S2)(+) cations and square pyramidal shape [SbCl5](2-) anions. The anions are disposed to form a polymeric chain in which each subunit is connected to the others through a Cl bridge. The organic cations are connected to these chains via H-bonding N-H center dot center dot center dot Cl and C-H center dot center dot center dot Cl. The intermolecular interactions which ensure the cohesion between different entities were analyzed by DFT calculations and Hirshfeld surface analysis. Ab-initio DFT calculations were also used to investigate geometric and electronic properties of complex 1 and AMT. Absorption, photoluminescence and infrared spectroscopy have been carried out. DFT calculations with different functionals have been used to gain a better insight into its vibrational and optical properties and a good agreement was found between experiments and calculations. The thermal stability of compound was studied by thermal analysis. Published by Elsevier B.V
A multi-modal dance corpus for research into real-time interaction between humans in online virtual environments
No full textWe present a new, freely available, multimodal corpus for research into, amongst other areas, real-time realistic interaction between humans in online virtual environments. The specific corpus scenario focuses on an online dance class application scenario where students, with avatars driven by whatever 3D capture technology are locally available to them, can learn choerographies with teacher guidance in an online virtual ballet studio. As the data corpus is focused on this scenario, it consists of student/teacher dance choreographies concurrently captured at two different sites using a variety of media modalities, including synchronised audio rigs, multiple cameras, wearable inertial measurement devices and depth sensors. In the corpus, each of the several dancers perform a number of fixed choreographies, which are both graded according to a number of specific evaluation criteria. In addition, ground-truth dance choreography annotations are provided. Furthermore, for unsynchronised sensor modalities, the corpus also includes distinctive events for data stream synchronisation. Although the data corpus is tailored specifically for an online dance class application scenario, the data is free to download and used for any research and development purposes
Antioxidant, antibacterial, and antileishmanial potential of Micromeria nervosa extracts and molecular mechanism of action of the bioactive compound
No full textAims: This study aimed to determine the antibacterial and antileishmanial potential of Micromeria nervosa extracts. The identification of the
antileishmanial compound and the study of its molecular mechanism of action have also been undertaken.
Methods and results: Ethanol extract showed high polyphenol content and diethyl ether extract exhibited high DPPH scavenging and low
beta-carotene bleaching activity (IC50 = 13.04 ± 0.99 and 200.18 ± 3.32 μg mL−1 , respectively). However, diethyl ether extract displayed high
antibacterial activity against Gram-positive strains including methicillin-resistant Staphylococcus aureus (MIC = 31.25 μg mL−1 ), Staph. aureus
ATCC6538 (MIC = 62.5 μg mL−1 ), and Listeria monocytogenes ATCC 19115 (MIC = 125 μg mL−1 ), as well as high antileishmanial activity against
the promastigote forms of L. infantum and L. major (IC50 = 11.45 and 14.53 μg mL−1 , respectively). The active compound was purified using
bioassay-guided fractionation and thin layer chromatography, and identified as ursolic acid using high-performance liquid chromatography coupled
with a photodiode array and mass spectrometry. The purified compound was strongly inhibitory against the promastigote and amastigote forms
of L. infantum and L. major (IC50 = 5.87 and 6.95 μg mL−1 versus 9.56 and 10. 68 μg mL−1 , respectively) without overt cytotoxicity against
Raw 264.7 macrophage cells (SI = 13.53 and 11.43, respectively). The commercial compound (ursolic acid) showed similar activity against
amastigotes and promastigotes forms of L. infantum and L. major. Moreover, its molecular mode of action against leishmaniasis seems to
involve the expression of the ODC and SPS genes involved in thiol pathway.
Conclusion: Extracts of M. nervosa can be considered as a potential alternative to antimicrobial and antileishmanial drugs
Audiovisual Analysis of Music Performances: Overview of an Emerging Field
No full textIn the physical sciences and engineering domains, music has traditionally been considered an acoustic phenomenon. From a perceptual viewpoint, music is naturally associated with hearing, i.e., the audio modality. Moreover, for a long time, the majority of music recordings were distributed through audio-only media, such as vinyl records, cassettes, compact discs, and mp3 files. As a consequence, existing automated music analysis approaches predominantly focus on audio signals that represent information from the acoustic rendering of music.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Multimedia Computin
clinical isolates
No full textAyed A, Essid R, Mankai H, et al. Synergistic antifungal activity and potential mechanism of action of a glycolipid like compound produced by Streptomyces blastmyceticus S108 against Candida clinical isolates. Journal of Applied Microbiology . 2023: lxad246.AIM: The present study aimed to investigate a novel antifungal compound produced by Streptomyces blastmyceticus S108 strain. Its effectiveness against clinical isolates of Candida species and its synergistic effect with conventional antifungal drugs were assessed and its molecular mechanism of action was further studied against C. albicans.; METHODS AND RESULTS: A newly isolated strain from Tunisian soil, Streptomyces blastmyceticus S108, showed significant antifungal activity against Candida species by well diffusion method. The butanolic extract of S108 strain supernatant exhibited the best anti-Candida activity with a minimal inhibitory concentration (MIC) value of 250 mug mL-1, determined by the microdilution method. The bio-guided purification steps of the butanolic extract were performed by chromatographic techniques. Among the fractions obtained, F13 demonstrated the highest level of activity, displaying a MIC of 31.25 mug mL-1. Gas Chromatography-Mass Spectrometry (GC-MS) and Electrospray Ionisation Mass Spectrometry (ESI-MS) analyses of this fraction (F13) revealed the glycolipidic nature of the active molecule with a molecular weight of 685.6 m/z. This antifungal metabolite remained stable to physicochemical changes and did not show hemolytic activity even at 4 MIC corresponding to 125 g mL-1 towards human erythrocytes. Besides, the glycolipid compound was combined with 5-flucytosine and showed a high synergistic effect with a FICI value 0.14 against C. albicans ATCC 10231. This combination resulted in a decrease of MIC values of 5-flucytosine and the glycolipid-like compound by 8 and 64-fold, respectively. The examination of gene expression in treated Candida albicans cells by qPCR revealed that the active compound tested alone or in combination with 5-flucytosine blocks the ergosterol biosynthesis pathway by down regulating the expression of ERG1, ERG3, ERG5, ERG11 and ERG25 genes.; CONCLUSION AND IMPACT OF THE STUDY: The new glycolipid like compound, produced by Streptomyces S108 isolate, could be a promising drug for medical use against pathogenic Candida isolates. © The Author(s) 2023. Published by Oxford University Press on behalf of Applied Microbiology International
A collaborative approach to video summarization
No full textThis poster describes an approach to video summarization based on the combination of several decision mechanisms provided by the partners of the KSpace European Network of Excellence. The system has been applied to the TRECVID 2008 BBC rushes summarization task
[Introduction to] Writing Centers at the Center of Change
No full textWriting Centers at the Center of Change looks at how eleven centers, internationally, adapted to change at their institutions, during a decade when their very success has become a valued commodity in a larger struggle for resources on many campuses.
Bringing together both US and international perspectives, this volume offers solutions for adapting to change in the world of writing centers, ranging from the logistical to the pedagogical, and even to the existential. Each author discusses the origins, appropriate responses, and partners to seek when change comes from within a school or outside it. Chapters document new programs being formed under changing circumstances, and suggest ways to navigate professional or pedagogical changes that may undermine the hard work of more than four decades of writing-center professionals.
The book’s audience includes writing center and learning-commons administrators, university librarians, deans, department chairs affiliated with writing centers. It will also be useful for graduate students in composition, rhetoric, and academic writing.https://scholarship.richmond.edu/bookshelf/1353/thumbnail.jp
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