107 research outputs found
Photon Antibunching and Collective Effects in the Fluorescence of Single Bichromophoric Molecules
The fluorescence of individual pairs of perylenemonoimide chromophores coupled via a short rigid linker is investigated. Photon antibunching is reported, indicating collective effects in the fluorescence, which are further substantiated by the observation of collective triplet off times and triplet lifetime shortening. The experimental findings are analyzed in terms of singlet-singlet and singlet-triplet annihilation based on Förster type energy transfer. The results reported here demonstrate that the statistical properties of the emission light of isolated single quantum systems can serve as a hallmark of intermolecular interactions
Photon Antibunching and Collective Effects in the Fluorescence of Single Bichromophoric Molecules
Bericht der Arbeitsgruppe "Open-Access-Publikationsplattformen"
Die Open-Access-Strategie des Landes Berlin von 2015 formuliert den Anspruch:
"Als langfristiges Ziel wird der Aufbau einer landesweiten Open-Access-
Infrastruktur für Monografien, Sammelbände und Zeitschriften in Kooperation
mit an wissenschaftlichen Einrichtungen agierenden
Infrastrukturdienstleistern, sowie mit in Berlin ansässigen Verlagen und
Publikationsdienstleistern angestrebt." Eine landesweite Berliner Open-Access-
Publikationsinfrastruktur soll dabei von den vorhandenen infrastrukturellen
und wissenschaftlichen Expertisen mehrerer, kooperativ agierender
Einrichtungen in Berlin profitieren und qualitativ hochwertige Publikationen
zu fairen Kosten umsetzen. Die Arbeitsgruppe "Open-Access-
Publikationsplattformen" mit Vertreter/innen mehrerer Berliner
Forschungseinrichtungen wurde beauftragt, dafür notwendige Vorarbeiten zu
leisten. So wurden im ersten Teil des Berichtes die an Berliner
wissenschaftlichen Einrichtungen bereits bestehenden
Publikationsinfrastrukturen erfasst. Im zweiten Teil wurden drei Modelle für
den Aufbau einer landesweiten Open-Access-Publikationsinfrastruktur für
Monografien, Sammelbände und Zeitschriften beschrieben. The Berlin Open Access
Strategy claims: "It is a long-term goal to establish a Berlin-wide open
access infrastructure for monographs, anthologies and periodicals – as a
cooperation of infrastructure service providers located at research
institutions as well as Berlin-based publishers and publishing service
providers." A Berlin-wide open access publishing infrastructure should be
based on the existing infrastructural and scholarly expertise of several,
cooperating institutions in Berlin and result in high-quality publications at
fair costs. A working group "Open Access Publishing Platforms" consisting of
representatives of several Berlin research institutions was set up and
commissioned to carry out the necessary preliminary work. The first part
reports on existing publication infrastructures run by Berlin research
institutions. The second part describes three possible model for re-
structuring and setting up a Berlin-wide open access publishing infrastructure
for monographs, anthologies and journals
Microbiological safety and cost-effectiveness of weekly breathing circuit changes in combination with heat moisture exchange filters: a prospective longitudinal clinical survey
Aim: To assess the safety and cost effectiveness of a usage for seven days of breathing circuit systems (BCSs) in combination with heat moisture exchanger filters (HMEF) in operation room anesthesia
Coherent Electronic Coupling versus Localization in Individual Molecular Dimers
We have investigated electronic excitation transfer in individual molecular dimers by time and spectrally resolved confocal fluorescence microscopy. The single molecule measurements allow for directly probing the distribution of the electronic coupling strengths due to static disorder in the polymer host. We find dimers where the excitation is delocalized (superradiant emission) while for others emission originates from a localized state. Transitions between delocalized and localized states as observed for a given dimer are attributed to structural fluctuations of the guest-host system
Significance of Medicinal Mushrooms in Integrative Oncology: A Narrative Review
Medicinal mushrooms are widely used in East Asia for the treatment of various diseases, especially in complementary cancer care. While there is a growing interest in medicinal mushrooms in Western countries and an increasing number of pre-clinical studies indicate distinct anti-cancer and regenerative properties, little is known about their potential relevance for clinical practice. This review aims to provide an overview of the clinical evidence, significance and potential role of medicinal mushrooms in complementary cancer care. Scientific databases for (randomized) controlled clinical trials evaluating whole spectrum formulations of medicinal mushrooms (mushroom powder and mushroom extracts) in cancer patients during and/or after conventional oncological treatment were searched. Eight studies met our inclusion criteria (eight randomized controlled trials, one controlled clinical trial). The medicinal mushrooms investigated were Agaricus sylvaticus (two trials), Agaricus blazei murill (two trials), Antrodia cinnamomea (one trial), Coriolus versicolor (one trial) and Ganoderma lucidum (three trials); all were compared to placebo and administered orally. A variety of cancer entities, outcomes and treatment durations were observed. Study results suggested beneficial effects of medicinal mushrooms, particularly quality of life and reduction of adverse effects of conventional therapies. Also, positive effects on antitumor activity and immunomodulation were reported, e.g., an increased activity of natural killer cells. In addition, results might suggest a longer survival of cancer patients receiving mushroom preparations, although in most studies this was not significant when compared to placebo. Adverse events of treatment with medicinal mushrooms were poorly reported; gastrointestinal reactions and a decrease in platelet cell count occurred in some cases. The methodological quality of most studies was generally unsatisfying and most results were insufficiently reported in several respects. Medicinal mushrooms may have a therapeutic potential for cancer patients during and after conventional oncological care with regards to quality of life, reduction of adverse effects of conventional care and possibly other surrogate parameters like immune function. There is an urgent need to investigate the safety and possible interactions of medicinal mushrooms. High-quality clinical research is warranted in order to clarify the potential of medicinal mushrooms in cancer therapy
Borane adducts of punicine and of its dehydroxy derivatives (pyridinium-1-yl)-2-and 3-phenolates
The natural product punicine (Punica granatum) exists in two tautomeric forms, the cross-conjugated mesomeric betaine 1-(pyridinium-1-yl)-2-hydroxy-phenyl-5-olate and the conjugated mesomeric betaine 1-(pyridinium-1-yl)-5-hydroxy-phenyl-2-olate. Punicine as well as its picoline derivatives reacted with tris(pentafluorophenyl)borane exclusively at the 2'-olate group to form zwitterionic borates. Correspondingly, the 5'-dehydroxy derivate of punicine, the conjugated heterocyclic mesomeric betaine 1-(pyridinium-1-yl)-phenyl-2-olate and its picoline derivatives also gave borates, whereas analogous reactions of the cross-conjugated isomer 2'-dehydroxypunicine [1-(pyridinium-1-yl)-phenyl-3-olatel did not result in the formation of stable adducts. (C) 2020 Elsevier Ltd. All rights reserved.Peer reviewe
HepatoNet1: a comprehensive metabolic reconstruction of the human hepatocyte for the analysis of liver physiology
We present HepatoNet1, a manually curated large-scale metabolic network of the human hepatocyte that encompasses >2500 reactions in six intracellular and two extracellular compartments.Using constraint-based modeling techniques, the network has been validated to replicate numerous metabolic functions of hepatocytes corresponding to a reference set of diverse physiological liver functions.Taking the detoxification of ammonia and the formation of bile acids as examples, we show how these liver-specific metabolic objectives can be achieved by the variable interplay of various metabolic pathways under varying conditions of nutrients and oxygen availability
Photon Antibunching and Collective Effects in the Fluorescence of Single Bichromophoric Molecules
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