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991.
A method for radionuclide‐induced (109Cd) energy‐dispersive X‐ray fluorescent (EDXRF) was used to determine Br, Fe, Rb, Sr, and Zn contents in intact and morphologic normal prostate tissues. Prostates were removed at necropsy from 64 men (mean age 36.5 years, range 13–60) who had died suddenly. All materials were divided into two parts. One part was morphologically examined, whereas chemical element contents of the other were estimated. Mean values (M ± SΕΜ) for mass fraction of Br, Fe, Rb, Sr, and Zn (mg kg?1 on dry‐weight basis) in the intact and morphologic normal prostate tissue were 35.5 ± 4.0, 107 ± 5.4, 17.1 ± 0.8, 1.9 ± 0.3, and 850 ± 79, respectively. Mean values (M ± SΕΜ) for Zn/Fe, Zn/Rb, and Zn/Sr ratios of mass fraction were 8.72 ± 0.80, 57.4 ± 7.2, and 567 ± 82, respectively. A strongly pronounced tendency of age‐related exponential increase in Zn mass fraction as well an increase in Zn/Fe, Zn/Rb, and Zn/Sr ratios in prostate was observed. A significant positive correlation was seen between the prostatic zinc and iron contents (p ≤ 0.05, r = 0.22) and between the prostatic zinc and bromine contents (p ≤ 0.01, r = 0.43). Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
992.
993.
Yijia Wang Yuansong Huang Lili Wang Huagang Ni Zhihai Cao Minghua Wu 《无机化学与普通化学杂志》2020,646(15):1303-1308
Py-IPH, a pyrene-based fluorogen with good thermal and mechanical stability was simply prepared by the Schiff base reaction and applied in the detection of antimony. Py-IPH presented special excimer fluorescence in the mixture of THF and water with 80 % of water, and exhibited perfect fluorescent response to antimony. The mechanism was demonstrated to be the increasing speed of the formation of pyrene excimers in the system owing to the coordination between antimony and IPH group in Py-IPH. Moreover, based on the special interaction between Py-IPH and antimony, it could distinguish antimony with other cations well with high specificity and selectivity. 相似文献
994.
Simon L. Porter Sophie M. Coulter Sreekanth Pentlavalli Garry Laverty 《Macromolecular bioscience》2020,20(7)
Peptide nanotubes are promising materials for a variety of biomedical applications with ultrashort (≤7 amino acids) forms providing particular promise for clinical translation. The manufacture of peptide nanotubes has, however, been associated with toxic organic solvents restricting clinical use. The purpose of this work is to formulate dipeptide nanotubes using mild techniques easily translated to industrial upscale and to characterize their physiochemical and biological properties. Phenylalanine‐phenylalanine variants can be successfully formulated using distilled water as demonstrated here. Formulations are homogenous in shape (tubular), with apparent size (50–260 nm) and a zeta potential of up to +30 mV. L‐(H2N‐FF‐COOH), and D‐enantiomers (H2N‐ff‐COOH) demonstrate no toxicity against glioblastoma cells and are explored for ability to deliver a model hydrophilic molecule, sodium fluorescein, at pH 5.5 (tumor) and 7.4 (physiological). Peptide nanotubes loaded with >85% sodium fluorescein, demonstrate burst release characteristics, fitting the Weibull model of drug release. This research provides important data contributing to the pharmaceutical formulation of peptide nanotubes as drug delivery platforms for hydrophilic drugs. 相似文献
995.
Yu Liu Zhaoran Hao Haigang Jiang Yajun Liu Yafei Wang Hua Tan Guohua Xie 《Tetrahedron》2018,74(3):425-432
Two novel dendrimer-like blue-emitting dinuclear cyclometalated iridium (III) complexes, namely (DNaTPA)2DBF(FIrpic)2 and (DPyTPA)2DBF(FIrpic)2, have been successfully synthesized and characterized. In which FIrpic is an iridium (III) bis[(4,6-difluorophenyl)pyridinato-N,C2′]picolate blue-emitting phosphorescent chromophore core, DBF is a 2,7-diphenyl-9H-fluorene bridging core, DNaTPA and DPyTPA are deep blue-emitting fluorescent chromophores composed by rigid high-triplet-energy dendrons of triphenylamine-functionalized naphthalene or pyrene units, and the peripheral dendrons are connected with the ancillary ligand of the emitting core through nonconjugated ether linkage. Their photophysical, thermal, electrochemical, as well as electrophosphorescent properties were primarily studied. Both iridium (III) complexes exhibit high efficient blue emission in solution (38.5% and 19.2%) and a typical FIrpic emission in 1,3-bis(N-carbzolyl)benzene (mCP) matrix (27.0% and 24.1%). Simple bilayer phosphorescent organic light-emitting diodes (PHOLEDs) with a configuration of ITO/PEDOT:PSS/mCP:dopants/TmPyPB/Liq/Al achieved high efficiencies of 12.96 cd/A for current efficiency (CE), 6162 cd/m2 for brightness, 6.22% for external quantum efficiency (EQE), and 3.13 lm/W for power efficiency (PE) with Commission International de L'Eclairage (CIE) coordinates of (0.19 ± 0.01, 0.35 ± 0.02) at only 2 wt% blend of (DNaTPA)2DBF(FIrpic)2. (DPyTPA)2DBF(FIrpic)2-doped devices also reach efficiencies of (9.14 cd/A, 7167 cd/m2, 4.41%, 2.61 lm/W) at the same doping concentration. The results demonstrate that the introduction of dendritic blue-emitting fluorescent chromophore grafted into the blue phosphorescent chromosphere core through nonconjugated linkage is an efficient way to achieve high-efficiency sky-blue emission. 相似文献
996.
997.
Dr. David C. Kennedy Dan Grünstein Dr. Chian‐Hui Lai Prof. Dr. Peter H. Seeberger 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(12):3794-3800
Carbohydrates on cell surfaces are critical components of the extracellular landscape and contribute to cell signalling, motility, adhesion and recognition. Multivalent effects are essential to these interactions that are inherently weak. Carbohydrate‐functionalised surfaces meet an important need for studying the multivalent interactions between carbohydrates and other biomolecules. Innovations in nanomaterials are revolutionising how these carbohydrate interfaces are studied and underscore their importance in the cosmos of biochemical interactions. 相似文献
998.
Mohd Marsin Sanagi Iqbal Hussain Wan Aini Wan Ibrahim Noorfatimah Yahaya Sazlinda Kamaruzaman Nurul Nabilah Zainal Abidin 《Separation & Purification Reviews》2016,45(1):28-49
Sample preparation is the backbone of any analytical procedure; it involves extraction and pre-concentration of the desired analytes; often at trace levels. The present article describes the applications of nanomaterials (carbon-based inorganic and polymeric materials) in miniaturized extraction such as solid phase micro-extraction, stir-bar sorptive extraction, liquid phase micro-extraction, and dispersive liquid phase micro-extraction in the analyses of aqueous samples. The nanoparticles used for micro-extractions are discussed on the basis of their chemical natures. The synthetic route and the preparation of nanomaterials are described along with the optimization strategies for micro-extraction. A comparison between the conventional materials and nanomaterials for micro-extraction is proposed. The key roles of the nanomaterials for the micro-extraction of different analytes such as drugs, pesticides, polycyclic aromatic hydrocarbons, proteins and peptides from aqueous samples are reported. The use of nanomaterials, combined with miniaturized micro-extraction techniques, proved to be highly promising for sample preparation of various matrices with analytes at trace levels. 相似文献
999.
Rational Design of Push–Pull Fluorene Dyes: Synthesis and Structure–Photophysics Relationship 下载免费PDF全文
Janah Shaya Dr. Fabien Fontaine‐Vive Dr. Benoît Y. Michel Prof. Dr. Alain Burger 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(30):10627-10637
Our work surveyed experimental and theoretical investigations to construct highly emissive D –π–A (D=donor, A=acceptor) fluorenes. The synthetic routes were optimised to be concise and gram‐scalable. The molecular design was first rationalised by varying the electron‐withdrawing group from an aldehyde, ketotriazole or succinyl to methylenemalonitrile or benzothiadiazole. The electron‐donating group was next varied from aliphatic or aromatic amines to saturated cyclic amines ranging from aziridine to azepane. Spectroscopic studies correlated with TD‐DFT calculations provided the optimised structures. The selected push–pull dyes exhibited visible absorptions, significant brightness, important solvatofluorochromism, mega‐Stokes shifts (>250 nm) and dramatic shifts in emission to the near‐infrared. The current library includes the comprehensive characterization of 16 prospective dyes for fluorescence applications. Among them, several fluorene derivatives bearing different conjugation anchors were tested for coupling and demonstrated to preserve the photophysical responses once further bound. 相似文献
1000.
Convenient Access to Fluorescent Probes by Chemoselective Acylation of Hydrazinopeptides: Application to the Synthesis of the First Far‐Red Ligand for Apelin Receptor Imaging 下载免费PDF全文
Dr. Jean‐François Margathe Dr. Xavier Iturrioz Pierre Regenass Iuliia A. Karpenko Dr. Nicolas Humbert Dr. Hugues de Rocquigny Prof. Marcel Hibert Dr. Catherine Llorens‐Cortes Dr. Dominique Bonnet 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(4):1399-1405
Herein, we develop a convenient method to facilitate the solution‐phase fluorescent labelling of peptides based on the chemoselective acylation of α‐hydrazinopeptides. This approach combines the advantages of using commercially available amine‐reactive dyes and very mild conditions, which are fully compatible with the chemical sensitivity of the dyes. The usefulness of this approach was demonstrated by the labelling of apelin‐13 peptide. Various fluorescent probes were readily synthesized, enabling the rapid optimization of their affinities for the apelin receptor. Thus, the first far‐red fluorescent ligand with sub‐nanomolar affinity for the apelin receptor was characterized and shown to track the receptor efficiently in living cells by fluorescence confocal microscopy. 相似文献