keyword
MENU ▼
Read by QxMD icon Read
search

Genger

keyword
https://www.readbyqxmd.com/read/28710516/perspectives-and-challenges-of-photon-upconversion-nanoparticles-part-i-routes-to-brighter-particles-and-quantitative-spectroscopic-studies
#1
REVIEW
Ute Resch-Genger, Hans H Gorris
Lanthanide-doped photon-upconversion nanoparticles (UCNPs) have been the focus of many research activities in materials and life sciences in the last 15 years because of their potential to convert light between different spectral regions and their unique photophysical properties. To fully exploit the application potential of these fascinating nanomaterials, a number of challenges have to be overcome, such as the low brightness, particularly of small UCNPs, and the reliable quantification of the excitation-power-density-dependent upconversion luminescence...
July 14, 2017: Analytical and Bioanalytical Chemistry
https://www.readbyqxmd.com/read/28687881/perspectives-and-challenges-of-photon-upconversion-nanoparticles-part-ii-bioanalytical-applications
#2
REVIEW
Hans H Gorris, Ute Resch-Genger
In Part II of this review series on lanthanide-doped photon-upconversion nanoparticles (UCNPs), we present and critically discuss the performance and suitability of UCNPs as background-free luminescent reporters in bioimaging and bioanalytical applications. The preparation of a biocompatible nanoparticle surface is an integral step for all life - science-related applications. UCNPs have found their way into a large number of diagnostic platforms, homogeneous and heterogeneous assay formats, and sensor applications...
July 7, 2017: Analytical and Bioanalytical Chemistry
https://www.readbyqxmd.com/read/28686275/power-dependent-upconversion-quantum-yield-of-nayf4-yb-3-er-3-nano-and-micrometer-sized-particles-measurements-and-simulations
#3
Martin Kaiser, Christian Würth, Marco Kraft, Iko Hyppänen, Tero Soukka, Ute Resch-Genger
Photophysical studies of nonlinear lanthanide-doped photon upconverting nanoparticles (UCNPs) increasingly used in biophotonics and photovoltaics require absolute measurements of the excitation power density (P)-dependent upconversion luminescence (UCL) and luminescence quantum yields (ΦUC) for quantifying the material performance, UCL deactivation pathways, and possible enhancement factors. We present here the P-dependence of the UCL spectra, ΦUC, and slope factors of the different emission bands of representative 25 nm-sized oleate-capped β-NaYF4:17% Yb(3+), 3% Er(3+) UCNPs dispersed in toluene and as powder as well as ΦUC of 3 μm-sized upconversion particles (UCμP), all measured with a newly designed integrating sphere setup, enabling controlled variation of P over four orders of magnitude...
July 7, 2017: Nanoscale
https://www.readbyqxmd.com/read/28536004/multimodality-imaging-approach-in-the-diagnosis-of-chronic-myocarditis-with-preserved-left-ventricular-ejection-fraction-mcpef-the-role-of-2d-speckle-tracking-echocardiography
#4
Mario Kasner, Aleksandar Aleksandrov, Felicitas Escher, Nidal Al-Saadi, Markus Makowski, Frank Spillmann, Martin Genger, Heinz-Peter Schultheiss, Uwe Kühl, Burkert Pieske, Daniel A Morris, Michel Noutsias, Carsten Tschöpe
BACKGROUND: Up to one third of patients with chronic myocarditis (MC) have preserved left ventricular (LV) ejection fraction (MCpEF). The purpose of this study was to evaluate the role of adding 2D speckle-tracking echocardiography (STE) to cardiac magnetic resonance imaging (cMRI) in the diagnosis of patients with MCpEF. METHODS AND RESULTS: We analyzed 67 patients with suspected MCpEF who underwent endomyocardial biopsy (EMB). Thirty-two patients with confirmed chronic myocardial inflammation by EMB served as study group (MCpEF) and the remaining patients (n=35) served as control group...
May 16, 2017: International Journal of Cardiology
https://www.readbyqxmd.com/read/28470291/excitation-wavelength-dependence-of-the-photoluminescence-quantum-yield-and-decay-behavior-of-cdse-cds-quantum-dot-quantum-rods-with-different-aspect-ratios
#5
D Geißler, C Würth, C Wolter, H Weller, U Resch-Genger
The excitation wavelength (λexc) dependence of the photoluminescence (PL) quantum yield (ΦPL) and decay behavior (τPL) of a series of CdSe/CdS quantum dot/quantum rods (QDQRs), consisting of the same spherical CdSe core and rod-shaped CdS shells, with aspect ratios ranging from 2 to 20 was characterized. λexc between 400-565 nm were chosen to cover the first excitonic absorption band of the CdSe core material, the onset of absorption of the CdS shell, and the region of predominant shell absorption. A strong λexc dependence of relative and absolutely measured ΦPL and τPL was found particularly for the longer QDQRs with higher aspect ratios...
May 17, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28430380/thermo-chromium-a-contactless-optical-molecular-thermometer
#6
Sven Otto, Norman Scholz, Thomas Behnke, Ute Resch-Genger, Katja Heinze
The unparalleled excited state potential energy landscape of the chromium(III)-based dye [1]3+ ([Cr(ddpd)2]3+; ddpd = N,N'-dimethyl-N,N'-dipyridin-2-yl-pyridin-2,6-diamine) enables a strong dual emission in the near infrared. The temperature dependence of this dual emission allows for the use of [1]3+ as an unprecedented molecular ratiometric thermometer in the 210 - 358 K temperature range in organic and in aqueous media. Incorporation of [1]3+ in biocompatible nanocarriers like 100 nm-sized polystyrene nanoparticles and solutol micelles provides nanodimensional thermometers operating under physiological conditions...
April 21, 2017: Chemistry: a European Journal
https://www.readbyqxmd.com/read/28405789/left-ventricular-strain-and-twisting-in-heart-failure-with-preserved-ejection-fraction-an-updated-review
#7
REVIEW
Marijana Tadic, Elisabeth Pieske-Kraigher, Cesare Cuspidi, Martin Genger, Daniel A Morris, Kun Zhang, Nina Alexandra Walther, Burket Pieske
Despite the high prevalence of the patients with heart failure with preserved ejection fraction (HFpEF), our knowledge about this entity, from diagnostic tools to therapeutic approach, is still not well established. The evaluation of patients with HFpEF is mainly based on echocardiography, as the most widely accepted tool in cardiac imaging. Identification of left ventricular (LV) diastolic dysfunction has long been considered as the only responsible for HFpEF, and its evaluation is still "sine qua non" of HFpEF diagnostics...
April 12, 2017: Heart Failure Reviews
https://www.readbyqxmd.com/read/28325045/particle-size-dependent-f%C3%A3-rster-resonance-energy-transfer-from-upconversion-nanoparticles-to-organic-dyes
#8
Verena Muhr, Christian Würth, Marco Kraft, Markus Buchner, Antje J Baeumner, Ute Resch-Genger, Thomas Hirsch
Upconversion nanoparticles (UCNPs) are attractive candidates for energy transfer-based analytical applications. In contrast to classical donor-acceptor pairs, these particles contain many emitting lanthanide ions together with numerous acceptor dye molecules at different distances to each other, strongly depending on the particle diameter. UCNPs with precisely controlled sizes between 10 and 43 nm were prepared and functionalized with rose bengal and sulforhodamine B by a ligand-exchange procedure. Time-resolved studies of the upconversion luminescence of the UCNP donor revealed a considerable shortening of the donor lifetime as a clear hint for Förster resonance energy transfer (FRET)...
April 18, 2017: Analytical Chemistry
https://www.readbyqxmd.com/read/28294258/excitation-power-dependent-population-pathways-and-absolute-quantum-yields-of-upconversion-nanoparticles-in-different-solvents
#9
C Würth, M Kaiser, S Wilhelm, B Grauel, T Hirsch, U Resch-Genger
The rational design of brighter upconversion nanoparticles (UCNPs) requires a better understanding of the radiationless deactivation pathways in these materials. Here, we demonstrate the potential of excitation power density (P)-dependent studies of upconversion (UC) luminescence intensities, slope factors, and absolute quantum yields (ΦUC) of popular β-NaYF4:20% Yb(3+),2% Er(3+) UCNPs of different surface chemistries in organic solvents, D2O, and water as a tool to gain deeper insight into the UC mechanism including population and deactivation pathways particularly of the red emission...
March 15, 2017: Nanoscale
https://www.readbyqxmd.com/read/28255124/-influential-factors-of-iron-deficient-anemia-among-infants-aged-8-months-based-on-a-case-control-study
#10
Xiao Gao, Yan Yan, Shiting Xiang, Hongyan Li, Shan Tan, Qiong He, Tingting Sha, Shiping Liu, Guangyu Zeng, Qiang Yan
To study the status and influential factors of iron deficient anemia (IDA) among infants aged 8 months in Changsha City.
 Methods: A case-control study was performed in this research. The case group including 105 8-month-old infants definitely diagnosed as IDA based on standardized blood test. Four-times numbers of age- and genger-matched infants without IDA were selected as a control group. Chi-square test and conditional logistic regression was used to analyze the influential factors for IDA.
 Results: The incidence rate of IDA among infants aged 8 months in Changsha City was 14...
February 28, 2017: Zhong Nan da Xue Xue Bao. Yi Xue Ban, Journal of Central South University. Medical Sciences
https://www.readbyqxmd.com/read/28000894/berberine-affects-osteosarcoma-via-downregulating-the-caspase-1-il-1%C3%AE-signaling-axis
#11
Hao Jin, Xin Jin, Boran Cao, Wenbo Wang
Osteosarcoma is one of the most devastating cancers with associated poor prognosis. Chronic bone inflammation frequently predisposes to tumorigenesis and progression of osteosarcoma. In the tumor inflammatory microenvironment, caspase-1 and its processed cytokines such as interleukin 1β (IL-1β) play an important role in the occurrence and development of cancer. Berberine is an isoquinoline alkaloid extracted from the dry root of Coptidis Rhizoma, which has been found to exhibit significant anticancer effects on a wide spectrum of carcinomas including osteosarcoma...
February 2017: Oncology Reports
https://www.readbyqxmd.com/read/27992232/optically-detected-degradation-of-nayf4-yb-tm-based-upconversion-nanoparticles-in-phosphate-buffered-saline-solution
#12
Olivija Plohl, Marco Kraft, Janez Kovač, Blaž Belec, Maja Ponikvar-Svet, Christian Würth, Darja Lisjak, Ute Resch-Genger
In a proof-of-concept study, we assessed different analytical and spectroscopic parameters for stability screening of differently sized β-NaYF4:20 mol % Yb(3+), 2 mol % Tm(3+) upconversion nanoparticles (UCNPs) exemplarily in the bioanalytically relevant buffer phosphate buffered saline (PBS; pH 7.4) at 37 and 50 °C. This included the potentiometric determination of the amount of released fluoride ions, surface analysis with X-ray photoelectron spectroscopy (XPS), and steady-state and time-resolved fluorescence measurements...
January 3, 2017: Langmuir: the ACS Journal of Surfaces and Colloids
https://www.readbyqxmd.com/read/27976907/four-and-five-component-syntheses-and-photophysical-properties-of-emission-solvatochromic-3-aminovinylquinoxalines
#13
Charlotte F Gers-Panther, Henry Fischer, Jan Nordmann, Theresa Seiler, Thomas Behnke, Christian Würth, Walter Frank, Ute Resch-Genger, Thomas J J Müller
3-Aminovinylquinoxalines are readily accessible from (hetero)aryl glyoxylic acids or heterocyclic π-nucleophiles by consecutive four- and five-component syntheses in the sense of an activation-alkynylation-cyclocondensation-addition sequence or glyoxylation-alkynylation-cyclocondensation-addition sequence in good yields. The title compounds are highly fluorescent with pronounced emission solvatochromicity and protochromic fluorescence quenching. Time-resolved fluorescence spectroscopy furnishes radiative and nonradiative fluorescence decay rates in various solvent polarities...
December 28, 2016: Journal of Organic Chemistry
https://www.readbyqxmd.com/read/27900430/visible-and-red-emissive-molecular-beacons-for-optical-temperature-measurements-and-quality-control-in-diagnostic-assays-utilizing-temperature-dependent-amplification-reactions
#14
Zerrin Fidan, Andy Wende, Ute Resch-Genger
Quality control requirements imposed on assays used in clinical diagnostics and point-of-care-diagnostic testing (POCT), utilizing amplification reactions performed at elevated temperatures of 35 to 95 °C are very stringent. As the temperature of a reaction vessel has a large impact on the specificity and sensitivity of the amplification reaction, simple tools for local in situ temperature sensing and monitoring are required for reaction and assay control. We describe here a platform of stem-and-loop structured DNA hairpins (molecular beacons, MBs), absorbing and emitting in the visible and red spectral region, rationally designed for precise temperature measurements in microfluidic assays for POCT, and their application for temperature measurements in a common DNA-based molecular biological assay utilizing thermophilic helicase-dependent amplification (tHDA)...
November 29, 2016: Analytical and Bioanalytical Chemistry
https://www.readbyqxmd.com/read/27790811/influence-of-label-and-charge-density-on-the-association-of-the-therapeutic-monoclonal-antibodies-trastuzumab-and-cetuximab-conjugated-to-anionic-fluorophores
#15
Jutta Pauli, Marieke Pochstein, Andrea Haase, Joanna Napp, Andreas Luch, Ute Resch-Genger
The design of bright and functional dye-protein conjugates requires hydrophilic and stable fluorophores with high molar absorption coefficients and high fluorescence quantum yields, which must not be prone to dimerization, as well as conservation of protein function and suppression of protein association. Although many synthetic dyes meet these needs, the influence of dye charge on bioconjugate performance is commonly neglected. This encouraged us to assess the spectroscopic properties, antibody functionality, binding behavior, folding, and association of conjugates of the therapeutic antibodies trastuzumab and cetuximab with the red cyanine dyes S0586, S2381, and 6SIDCC (bearing two, three, and six sulfonate groups, respectively)...
January 3, 2017: Chembiochem: a European Journal of Chemical Biology
https://www.readbyqxmd.com/read/27373999/ellman-s-and-aldrithiol-assay-as-versatile-and-complementary-tools-for-the-quantification-of-thiol-groups-and-ligands-on-nanomaterials
#16
Marko Moser, Ralf Schneider, Thomas Behnke, Thomas Schneider, Jana Falkenhagen, Ute Resch-Genger
Simple, fast, and versatile methods for the quantification of thiol groups are of considerable interest not only for protein analysis but also for the characterization of the surface chemistry of nanomaterials stabilized with thiol ligands or bearing thiol groups for the subsequent (bio-) functionalization via maleimide-thiol chemistry. Here, we compare two simple colorimetric assays, the widely used Ellman's assay performed at alkaline pH and the aldrithiol assay executed at acidic and neutral pH, with respect to their potential for the quantification of thiol groups and thiol ligands on different types of nanoparticles like polystyrene nanoparticles, semiconductor nanocrystals (SC NC), and noble metal particles, and we derive criteria for their use...
September 6, 2016: Analytical Chemistry
https://www.readbyqxmd.com/read/27357335/ph-and-concentration-dependence-of-the-optical-properties-of-thiol-capped-cdte-nanocrystals-in-water-and-d2o
#17
R Schneider, F Weigert, V Lesnyak, S Leubner, T Lorenz, T Behnke, A Dubavik, J-O Joswig, U Resch-Genger, N Gaponik, A Eychmüller
The optical properties of semiconductor nanocrystals (SC NCs) are largely controlled by their size and surface chemistry, i.e., the chemical composition and thickness of inorganic passivation shells and the chemical nature and number of surface ligands as well as the strength of their bonds to surface atoms. The latter is particularly important for CdTe NCs, which - together with alloyed CdxHg1-xTe - are the only SC NCs that can be prepared in water in high quality without the need for an additional inorganic passivation shell...
July 28, 2016: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/27281039/tuning-the-surface-of-nanoparticles-impact-of-poly-2-ethyl-2-oxazoline-on-protein-adsorption-in-serum-and-cellular-uptake
#18
Olga Koshkina, Dana Westmeier, Thomas Lang, Christoph Bantz, Angelina Hahlbrock, Christian Würth, Ute Resch-Genger, Ulrike Braun, Raphael Thiermann, Christoph Weise, Murat Eravci, Benjamin Mohr, Helmut Schlaad, Roland H Stauber, Dominic Docter, Annabelle Bertin, Michael Maskos
Due to the adsorption of biomolecules, the control of the biodistribution of nanoparticles is still one of the major challenges of nanomedicine. Poly(2-ethyl-2-oxazoline) (PEtOx) for surface modification of nanoparticles is applied and both protein adsorption and cellular uptake of PEtOxylated nanoparticles versus nanoparticles coated with poly(ethylene glycol) (PEG) and non-coated positively and negatively charged nanoparticles are compared. Therefore, fluorescent poly(organosiloxane) nanoparticles of 15 nm radius are synthesized, which are used as a scaffold for surface modification in a grafting onto approach...
September 2016: Macromolecular Bioscience
https://www.readbyqxmd.com/read/27038055/streptavidin-conjugation-and-quantification-a-method-evaluation-for-nanoparticles
#19
Pablo Darío Quevedo, Thomas Behnke, Ute Resch-Genger
Aiming at the development of validated protocols for protein conjugation of nanomaterials and the determination of protein labeling densities, we systematically assessed the conjugation of the model protein streptavidin (SAv) to 100-, 500-, and 1000-nm-sized polystyrene and silica nanoparticles and dye-encoded polymer particles with two established conjugation chemistries, based upon achievable coupling efficiencies and labeling densities. Bioconjugation reactions compared included EDC/sulfo NHS ester chemistry for direct binding of the SAv to carboxyl groups at the particle surface and maleimide-thiol chemistry in conjunction with heterobifunctional PEG linkers and aminated nanoparticles (NPs)...
June 2016: Analytical and Bioanalytical Chemistry
https://www.readbyqxmd.com/read/27007448/highly-fluorescent-dye-nanoclay-hybrid-materials-made-from-different-dye-classes
#20
Markus Grabolle, Marian Starke, Ute Resch-Genger
Nanoclays like laponites, which are commercially avaible in large quantities for a very moderate price, provide a facile solubilization strategy for hydrophobic dyes without the need for chemical functionalization and can act as a carrier for a high number of dye molecules. This does not require reactive dyes, amplifies fluorescence signals from individual emitters due to the high number of dyes molecules per laponite disk, and renders hydrophobic emitters applicable in aqueous environments. Aiming at the rational design of bright dye-loaded nanoclays as a new class of fluorescent reporters for bioanalysis and material sciences and the identification of dye structure-property relationships, we screened a series of commercial fluorescent dyes, differing in dye class, charge, and character of the optical transitions involved, and studied the changes of their optical properties caused by clay adsorption at different dye loading concentrations...
April 12, 2016: Langmuir: the ACS Journal of Surfaces and Colloids
keyword
keyword
33551
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"