Search results for "Visible"
showing 10 items of 351 documents
Visible-light photoredox catalyzed synthesis of pyrroloisoquinolines via organocatalytic oxidation/[3 + 2] cycloaddition/oxidative aromatization reac…
2014
Beilstein journal of organic chemistry 10, 1233-1238 (2014). doi:10.3762/bjoc.10.122
Bio serves nano: biological light-harvesting complex as energy donor for semiconductor quantum dots.
2012
Light-harvesting complex (LHCII) of the photosynthetic apparatus in plants is attached to type-II core-shell CdTe/CdSe/ZnS nanocrystals (quantum dots, QD) exhibiting an absorption band at 710 nm and carrying a dihydrolipoic acid coating for water solubility. LHCII stays functional upon binding to the QD surface and enhances the light utilization of the QDs significantly, similar to its light-harvesting function in photosynthesis. Electronic excitation energy transfer of about 50% efficiency is shown by donor (LHCII) fluorescence quenching as well as sensitized acceptor (QD) emission and corroborated by time-resolved fluorescence measurements. The energy transfer efficiency is commensurable …
Novel two-step synthesis of gold nanoparticles capped with bile acid conjugates
2008
Bile acids and their conjugates are physiologically important molecules. Syntheses and structure elucidation combined with investigation of properties and applications of bile acids and their derivatives are of academic interest. The concept of using bile acids and their conjugates in nanoscience is a novel idea, which opens up fascinating prospects. In this article, an easy and simple route for obtaining N-lithocholyl-L-(cysteine ethyl ester) (3), capable of effectively capping and stabilizing metal nanoparticles, is described. The whole synthetic route needs only two steps giving a moderate to good yield. The gold NPs are characterized by elemental analysis, UV spectroscopy, and TEM. Addi…
Dual Cherenkov Radiation-Induced Near-Infrared Luminescence Imaging and Photodynamic Therapy toward Tumor Resection
2020
International audience; Cherenkov radiation (CR), the blue light seen in nuclear reactors, is emitted by some radiopharmaceuticals. This study showed that (1) a portion of CR could be transferred in the region of the optical spectrum, where biological tissues are most transparent: as a result, upon radiance amplification in the near-infrared window, the detection of light could occur twice deeper in tissues than during classical Cherenkov luminescence imaging and (2) Cherenkov-photodynamic therapy (CR-PDT) on cells could be achieved under conditions mimicking unlimited depth using the CR-embarked light source, which is unlike standard PDT, where light penetration depth is limited in biologi…
The three-dimensional structure of Drosophila melanogaster (6–4) photolyase at room temperature
2021
A crystal structure of a photolyase at room temperature confirms the structural information obtained from cryogenic crystallography and paves the way for time-resolved studies of the photolyase at an X-ray free-electron laser.
Coordination networks incorporating halogen-bond donor sites and azobenzene groups
2016
Two Zn coordination networks, {[Zn(1)(Py)2]2(2-propanol)}n (3) and {[Zn(1)2(Bipy)2](DMF)2}n (4), incorporating halogen-bond (XB) donor sites and azobenzene groups have been synthesized and fully characterized. Obtaining 3 and 4 confirms that it is possible to use a ligand wherein its coordination bond acceptor sites and XB donor sites are on the same molecular scaffold (i.e., an aromatic ring) without interfering with each other. We demonstrate that XBs play a fundamental role in the architectures and properties of the obtained coordination networks. In 3, XBs promote the formation of 2D supramolecular layers, which, by overlapping each other, allow the incorporation of 2-propanol as a gues…
Pressure and Thermally Induced Spin Crossover in a 2D Iron(II) Coordination Polymer {Fe[bipy(ttr)2]}n
2021
Using magnetic measurements and UV -visible spectroscopy we have studied the pressure influence on the spin crossover (SCO) properties of the 2D Fe (II) coordination polymer formulated {Fe[bipy(ttr) 2 ]} n . At variable temperature and fixed pressure, we have measured the magnetic property of this compound. Under different pressures and at room temperature, the visible spectroscopy has been observed. The magnetic experiment displays a two-step spin crossover behavior under pressure. The visible spectroscopic measurements at room temperature show a spin crossover with an asymmetric hysteresis at 0.4GPa.
Virtual temporal bone: an interactive 3-dimensional learning aid for cranial base surgery.
2009
OBJECTIVE: We have developed an interactive virtual model of the temporal bone for the training and teaching of cranial base surgery. METHODS: The virtual model was based on the tomographic data of the Visible Human Project. The male Visible Human's computed tomographic data were volumetrically reconstructed as virtual bone tissue, and the individual photographic slices provided the basis for segmentation of the middle and inner ear structures, cranial nerves, vessels, and brainstem. These structures were created by using outlining and tube editing tools, allowing structural modeling either directly on the basis of the photographic data or according to information from textbooks and cadaver…
Anatomy online: presentation of a detailed WWW atlas of human gross anatomy--reference for medical education.
2002
We present an online anatomy atlas based on the Visible Human Project (VHP) of the US National Library of Medicine. The objective is to provide original unlabeled as well as labeled sections of the human body of high quality and resolution on the Internet, for use in basic and continuing medical education. For a representative overview of the body, 370 axial sections were selected from the male and female data base of the VHP with special regard to regions of clinical interest. Each section is accompanied by its corresponding computer tomography (CT) image and, if available, magnetic resonance images (MRI) for quick and easy comparison of morphologic and radiologic structures. The sections …
Fabrication and characterization of tuned Gaussian mirrors for the visible and the near infrared
1988
A thin-film technique has been developed for vacuum fabrication of mirrors with Gaussian reflectivity profiles. Samples with diameters from 2 to 8 mm and assigned maximum reflectivities for visible or near-IR wavelengths have been made and their optical properties evaluated. By properly choosing both the geometry of the evaporation source and the masking system, one can obtain quasi-Gaussian or super-Gaussian reflectivity profiles.