(OC-6-13)-Difluoridooxidobis(propan-2-ol)(propan-2-olato)vanadium(V)

The distorted octahedral title complex, [V-V(C3H7O)(C3H8O)(2)F2O], was synthesized via ligand exchange at [(VO)-O-V(OiPr)(3)] with aqueous hydrogen fluoride in propan-2-ol and crystallized from (D) chloroform at 238 K after a few weeks. Crystal structure determination shows two C-1-symmetric moieties to be present in the asymmetric unit, forming infinite chains along [100] via hydrogen bonds. The compound provides the first crystal structure containing the [VF2O(OiPr)] motif

Invariom-model refinement and Hirshfeld surface analysis of well-ordered solvent-free dibenzo-21-crown-7

Crown ethers and their supra­molecular derivatives are well-known chelators and scavengers for a variety of cations, most notably heavier alkali and alkaline-earth ions. Although they are widely used in synthetic chemistry, available crystal structures of uncoordinated and solvent-free crown ethers regularly suffer from disorder. In this study, we present the X-ray crystal structure analysis of well-ordered solvent-free crystals of dibenzo-21-crown-7 (systematic name: dibenzo[b,k]-1,4,7,10,13,16,19-hepta­oxa­cyclo­heneicosa-2,11-diene, C22H28O7). Because of the quality of the crystal and diffraction data, we have chosen invarioms, in addition to standard independent spherical atoms, for modelling and briefly discuss the different refinement results. The electrostatic potential, which is directly deducible from the invariom model, and the Hirshfeld surface are analysed and complemented with inter­action-energy computations to characterize inter­molecular contacts. The boat-like mol­ecules stack along the a axis and are arranged as dimers of chains, which assemble as rows to form a three-dimensional structure. Dispersive C—H...H—C and C—H...π inter­actions dominate, but nonclassical hydrogen bonds are present and reflect the overall rather weak electrostatic influence. A fingerprint plot of the Hirshfeld surface summarizes and visualizes the inter­molecular inter­actions. The insight gained into the crystal structure of dibenzo-21-crown-7 not only demonstrates the power of invariom refinement, Hirshfeld surface analysis and inter­action-energy computation, but also hints at favourable conditions for crystallizing solvent-free crown ethers

Responding to Open Access: How German Museums use Digital Content

Museums are expected to safeguard society’s cultural heritage while also making it publicly available to all. Recently, the digital transformation increased political and societal claims on museums to make their digital content openly available. This paper explores museums’ reactions to this claim and looks at how museums currently utilize their digital content. By analysing qualitative interviews with German museum officials we have found museums to follow four different types of strategies which are ‘Societal engagement’, ‘Safeguarding of heritage related knowledge’, ‘Scientific infrastructure’ and ‘marketing ends’. These were embedded in museums’ organizational identity and the prioritising of some of their tasks

Untersuchung von entzündungsrelevanter interzellulärer Kommunikation nach Bestrahlung in einem 3D-Haut-Modell

Die Haut wird bei der Bestrahlung zu diagnostischen oder therapeutischen Zwecken, wie zum Beispiel der Tumortherapie, immer mitbestrahlt. Dies kann bei hohen Dosen, wie sie für die Tumortherapie angewandt werden, zu unerwünschten Nebeneffekten führen, bei niedrigen Dosen aber auch einen positiven, anti-entzündlichen Effekt haben, den man sich bei der Therapie chronisch entzündlicher Erkrankungen zu Nutze macht. Es gibt bisher nur sehr wenige aussagekräftige Daten in der Literatur, die Aufschluss über die Wirkmechanismen der Niedrigdosisbestrahlung, insbesondere auf humane Haut, geben. Für die Bestrahlung von Hautäquivalenten oder Hautexplantaten mit Kohlenstoffionen liegen keine publizierten Daten vor und auch für Röntgen- und UV-B-Bestrahlung sind diese meist lückenhaft. Ziel dieser Arbeit war es, eine systematische Übersicht über die verschiedenen auftretenden Effekte hinsichtlich Zelltod, Zytokinfreisetzung und struktureller und morphologischer Veränderungen nach der Bestrahlung mit ionisierender Röntgen- und- Kohlenstoffbestrahlung verglichen zu nicht-ionisierender UV-B-Strahlung zu geben. Hierfür wurden Modellsysteme verschiedener Komplexität verwendet, die von Keratinozyten-Monokulturen über Co-Kulturen bis hin zu humanen Hautäquivalenten reicht. Ausserdem ermöglichte ein, in Zusammenarbeit mit der Hautklinik Darmstadt gestellter, Ethikantrag die Untersuchung humaner Haut in vitro. Zelltod spielt nach ionisierender Strahlung weder in Form von Apoptose noch Nekrose eine Rolle. Lediglich nach UV-B-Bestrahlung konnte in Monokulturen von Keratinozyten klassische, Caspase 3-abhängige Apoptose detektiert werden. Die Zytokinfreisetzung zeigt für alle Strahlenqualitäten und Modellsysteme ein pro-inflammatorisches Muster, welches durch die Erhöhung der IL-1alpha-, IL-6- und IL-8-Freisetzung charakterisiert ist. Je nach Strahlenqualität unterscheidet sich die Kinetik der Zytokinfreisetzung. Nach UV-B-Bestrahlung kommt es zu einer sehr schnellen Reaktion, die 48 h nach der Bestrahlung bereits großteils abgeschlossen ist, während sie bei Röntgenbestrahlung 24 h und 48 h und bei Kohlenstoffbestrahlung erst 48 h nach der Bestrahlung auftritt. Durch die Bestrahlung kommt es zu verschiedenen Veränderungen der Struktur und Morphologie als auch der Differenzierung der Hautäquivalente. In dieser Arbeit wurde erstmals Parakeratose, das Auftreten von pyknotischen Kernen in der vitalen Epidermis, Hyperkeratose und die Struktur der Basalzellen nach der Bestrahlung mit verschiedenen Strahlenqualitäten quantitativ bzw. semiquantitativ ausgewertet und verglichen. Nach der Bestrahlung mit höheren Dosen Röntgenstrahlung und Kohlenstoffionen kommt es zu einer beschleunigten Differenzierung, die sich als Hyperkeratose äussert. Parakeratose, die durch eine fehlerhafte Differenzierung zustande kommt, tritt vermehrt nach hohen Intensitäten UV-B-Strahlung und höheren Dosen Kohlenstoffionen und seltener für hohe Dosen Röntgenstrahlung von 10 Gy auf. Insbesondere für niedrige Dosen Röntgenstrahlung tritt ein Polaritätsverlust der Basalzellen auf. Ausserdem ist für diese Dosis sowohl die Proliferation erhöht, als auch das Expressionsmuster von E-Cadherin verändert. Die hier beobachteten Veränderungen nach Bestrahlung zeigen, dass es für alle Bestrahlungsarten zu einem pro-inflammatorichen Effekt kommt, der für niedrige Dosen lediglich schwächer ausgeprägt ist. Ein Hinweis auf eine höhere Effektivität von Kohlenstoffionen konnte trotz des höheren LETs bei den hier betrachteten Endpunkten ebenfalls nicht gezeigt werden. Erste Versuche für humane Haut haben die Ergebnisse für Hautäquivalente weitestgehend bestätigt und zeigen, dass die Anwesenheit von Langerhanszellen die Effekte auf Bestrahlung nicht grundlegend verändert. Der im Rahmen dieser Arbeit eingereichte und bewilligte Ethikantrag und die Etablierung der Kultivierung und Bestrahlung humaner Hautexplantate hat hier den Weg für weitere Versuche geebnet

Radiation-induced cardiac side-effects:The lung as target for interacting damage and intervention

Radiotherapy is part of the treatment for many thoracic cancers. During this treatment heart and lung tissue can often receive considerable doses of radiation. Doses to the heart can potentially lead to cardiac effects such as pericarditis and myocardial fibrosis. Common side effects after lung irradiation are pneumonitis and pulmonary fibrosis. It has also been shown that lung irradiation has effects on cardiac function. In a rat model lung irradiation caused remodeling of the pulmonary vasculature increasing resistance of the pulmonary vascular bed, leading to enhanced pulmonary artery pressure, right ventricle hypertrophy and reduced right ventricle performance. Even more pronounced effects are observed when both, lung and heart are irradiated. The effects observed after lung irradiation show striking similarities with symptoms of pulmonary arterial hypertension. In particular, the vascular remodeling in lung tissue seems to have similar underlying features. Here, we discuss the similarities and differences of vascular remodeling observed after thoracic irradiation compared to those in pulmonary arterial hypertension patients and research models. We will also assess how this knowledge of similarities could potentially be translated into interventions which would be beneficial for patients treated for thoracic tumors, where dose to lung tissue is often unavoidable

Regional Responses in Radiation-Induced Normal Tissue Damage

Simple SummarySide effects caused by the concomitant irradiation of normal tissue during radiotherapy for cancer treatment can negatively affect the patient's quality of life and limit the radiation dose that can safely be administered to the tumor. Recently, considerable developments have been achieved in radiotherapy and imaging technologies, allowing the selective sparing of the regions within organs that contribute most to the development of these side effects. This review discusses regional variation in the response to radiation in several organs, including the brain, salivary glands, cardiopulmonary system, pancreas, and bladder. Regional responses are shown to originate from general principles, such as the localization of target cells or function. We conclude that regional responses are a general phenomenon that should be studied in other organs. This will facilitate further optimization of the use of modern radiotherapy technologies.Normal tissue side effects remain a major concern in radiotherapy. The improved precision of radiation dose delivery of recent technological developments in radiotherapy has the potential to reduce the radiation dose to organ regions that contribute the most to the development of side effects. This review discusses the contribution of regional variation in radiation responses in several organs. In the brain, various regions were found to contribute to radiation-induced neurocognitive dysfunction. In the parotid gland, the region containing the major ducts was found to be critical in hyposalivation. The heart and lung were each found to exhibit regional responses while also mutually affecting each other's response to radiation. Sub-structures critical for the development of side effects were identified in the pancreas and bladder. The presence of these regional responses is based on a non-uniform distribution of target cells or sub-structures critical for organ function. These characteristics are common to most organs in the body and we therefore hypothesize that regional responses in radiation-induced normal tissue damage may be a shared occurrence. Further investigations will offer new opportunities to reduce normal tissue side effects of radiotherapy using modern and high-precision technologies.</p

Ternary transition-metal fluoride precursors for the fluorolytic sol-gel route: new insights into speciation and decomposition

The nanoscaled ternary transition-metal fluorides Li3MF6 (M = V, Fe, Mn) and Li2NiF4 are promising candidates for cathode materials in high-voltage lithium-ion batteries. The fluorolytic route to these compounds relies on thermal decomposition of a hitherto uncharacterised precursor mixture produced from acetylacetonates and hydrofluoric acid. By addition of pyridine, different cationic, electroneutral and anionic complexes containing the motifs [MFn]((3-n)+) (n = 0-4) have been trapped and characterised by single-crystal X-ray diffraction and IR spectroscopy. Based on the results, a model of successive and incomplete fluorination is proposed for the speciation and formation of the precursor. The decomposition of the latter has been monitored via thermogravimetry (TG) and differential scanning calorimetry (DSC)

Radiation-induced cardiac side-effects: The lung as target for interacting damage and intervention

Radiotherapy is part of the treatment for many thoracic cancers. During this treatment heart and lung tissue can often receive considerable doses of radiation. Doses to the heart can potentially lead to cardiac effects such as pericarditis and myocardial fibrosis. Common side effects after lung irradiation are pneumonitis and pulmonary fibrosis. It has also been shown that lung irradiation has effects on cardiac function. In a rat model lung irradiation caused remodeling of the pulmonary vasculature increasing resistance of the pulmonary vascular bed, leading to enhanced pulmonary artery pressure, right ventricle hypertrophy and reduced right ventricle performance. Even more pronounced effects are observed when both, lung and heart are irradiated.The effects observed after lung irradiation show striking similarities with symptoms of pulmonary arterial hypertension. In particular, the vascular remodeling in lung tissue seems to have similar underlying features. Here, we discuss the similarities and differences of vascular remodeling observed after thoracic irradiation compared to those in pulmonary arterial hypertension patients and research models. We will also assess how this knowledge of similarities could potentially be translated into interventions which would be beneficial for patients treated for thoracic tumors, where dose to lung tissue is often unavoidable

Synthesis of ternary transition metal fluorides Li 3MF 6via a sol-gel route as candidates for cathode materials in lithium-ion batteries

A sol-gel route for ternary lithium fluorides of transition metals (M) is presented allowing the synthesis of Li 3MF 6-type and Li 2MF 5-type compounds. It is based on a fluorolytic process using transition metal acetylacetonates as precursors. The domain size of the obtained powders can be controlled by modifying the conditions of synthesis. 6Li and 7Li magic angle spinning (MAS) nuclear magnetic resonance (NMR) spectroscopy is used to study local environments of the Li ions in orthorhombic and monoclinic Li 3VF 6 as well as Li 2MnF 5. The number of magnetically inequivalent Li sites found by MAS NMR is in agreement with the respective crystal structure of the compounds studied. Quantum chemical calculations show that all materials have high de-lithiation energies making them suitable candidates to be used as high-voltage battery cathode materials. © 2012 The Royal Society of Chemistry

Thoughts on heavy-ion physics in the high luminosity era: the soft sector

This document summarizes thoughts on opportunities in the soft-QCD sector from high-energy nuclear collisions at high luminosities.Comment: 19 page