Search results for "diary"
showing 10 items of 173 documents
Lichtaktivierte Sensoren zur empfindlichen Amindetektion
2017
Unsere neue, einfache und akkurate colorimetrische Methode basiert auf Diarylethenen (DAEs) zur schnellen Detektion einer grosen Vielfalt primarer und sekundarer Amine. Die Sensoren bestehen aus aldehyd- oder ketonsubstituierten Diarylethenen, die selektiv ausgehend vom geschlossenen Isomer eine amininduzierte Entfarbungsreaktion eingehen. Somit konnen diese Sensoren zum gewunschten Zeitpunkt durch Lichteinstrahlung aktiviert werden und erlauben eine Empfindlichkeit der Amindetektion bis hinab zu 10−6 m in Losung. Zusatzlich ermoglicht die Immobilisierung auf Papier den Nachweis biogener Amine wie Cadaverin in der Gasphase oberhalb eines Grenzwerts von 12 ppbv innerhalb von 30 Sekunden.
Light-Activated Sensitive Probes for Amine Detection
2017
Our new, simple, and accurate colorimetric method is based on diarylethenes (DAEs) for the rapid detection of a wide range of primary and secondary amines. The probes consist of aldehyde- or ketone-substituted diarylethenes, which undergo an amine-induced decoloration reaction, selectively to give the ring-closed isomer. Thus, these probes can be activated at the desired moment by light irradiation, with a sensitivity that allows the detection of amines at concentrations as low as 10exp−6 M in solution. In addition, the practical immobilization of DAEs on paper makes it possible to detect biogenic amines, such as cadaverine, in the gas phase above a threshold of 12 ppbv within 30 seconds. P…
Proton‐Gated Ring‐Closure of a Negative Photochromic Azulene‐Based Diarylethene
2020
Abstract Proton‐responsive photochromic molecules are attractive for their ability to react on non‐invasive rapid optical stimuli and the importance of protonation/deprotonation processes in various fields. Conventionally, their acidic/basic sites are on hetero‐atoms, which are orthogonal to the photo‐active π‐center. Here, we incorporate azulene, an acid‐sensitive pure hydrocarbon, into the skeleton of a diarylethene‐type photoswitch. The latter exhibits a novel proton‐gated negative photochromic ring‐closure and its optical response upon protonation in both open and closed forms is much more pronounced than those of diarylethene photoswitches with hetero‐atom based acidic/basic moieties. …
Exporting Corporate Governance: Do Foreign and Local Proxy Advisors Differ?
2018
Prior research documents that the large US-based proxy advisors, Institutional Shareholder Services (ISS) and Glass Lewis (GL), play an important role as information intermediaries in corporate governance worldwide. We provide initial evidence on the role of local proxy advisors, using the German setting. We analyse voting recommendations by local (IVOX) and foreign (ISS, GL) proxy advisors. First, we find that IVOX’s voting recommendations differ substantially from those of ISS and GL. Second, we observe that IVOX’s against-recommendations are significantly negatively associated with voting support. Third, we find that this association is particularly negative for voting outcomes at compan…
An interaction orientation approach to SME-Intermediaries relationships
2021
Abstract Small and medium-sized enterprises (SMEs) engaging in foreign operations have drawn significant research attention in recent years. One of the aspects linked to such operations is SMEs’ expansion to foreign markets, often relying on local intermediaries. These intermediaries provide the firms with valuable resources such as market knowledge and recognition and reduce foreign operations’ costs. Hence, they are often considered as strategic partners. The current study aims to expand the existing knowledge regarding the relationships between business to business SMEs and their intermediaries by exploring interaction orientation as an organizational cultural aspect and its linkage to t…
Which innovation strategy do internationalised firms follow?: evidence from Spain
2016
This paper compares the innovation strategy of internationalised firms, foreign-owned subsidiaries and domestic exporters, relative to firms that serve the domestic market only. The analysis is performed on a sample of manufacturing Spanish firms over the period 2006-2011. We not only focus on different forms of innovation, distinguishing between imitation and pioneer innovation, but also on the heterogeneity of exporters and foreign-owned firms. We find that foreign-owned firms and domestic exporters (excluding those serving only the EU market) are more likely to introduce market novelties ahead of competitors in low-tech sectors and, to a lesser extent, imitate more than local firms. Howe…
Characterisation of Diarylheptanoid- and Flavonoid-type Phenolics in Corylus avellana L. Leaves and Bark by HPLC/DAD-ESI/MS
2013
Introduction The leaves of Corylus avellana L. (common hazel, Betulaceae), a plant with a wide distribution in Europe, have been used in folk medicine for various diseases, but phytochemical exploration of C. avellana is still incomplete. To the best of our knowledge there is no previous report concerning diarylheptanoids in C. avellana, although these compounds show a frequent occurrence among Betulaceae plants. Objective To improve existing online chromatographic methods for the investigation of the phenolic compounds in C. avellana leaves and bark, focusing on diarylheptanoid-type molecules. Methods Dried and powdered leaves and bark of C. avellana were extracted with increasing polarity…
Screening of ligands for the Ullmann synthesis of electron-rich diaryl ethers
2012
In the search for new ligands for the Ullmann diaryl ether synthesis, permitting the coupling of electron-rich aryl bromides at relatively low temperatures, 56 structurally diverse multidentate ligands were screened in a model system that uses copper iodide in acetonitrile with potassium phosphate as the base. The ligands differed largely in their performance, but no privileged structural class could be identified.
Synthesis and magnetic properties of an iron 1,2-bisthienyl perfluorocyclopentene photochromic coordination compound
2011
Abstract The coordination compound Fe(BM-4-PTP) 2 (NCS) 2 ⋅2MeOH ( 1 ) including the photoisomerizable ligand BM-4-PTP (1,2-bis(2′-methyl-5′-(pyrid-4″-yl)thien-3′-yl)perfluorocyclopentene) was obtained as an orange powder. The powder turns blue upon photocyclization of the 1,2-bisthienyl photochromic ligand induced by UV light irradiation at room temperature. Photocycloreversion is obtained by visible light irradiation of the material in the solid state. The orange and blue powders were investigated over the temperature range (5–293 K) and pressure range (1 bar–12 kbar) by magnetic susceptibility measurements and variable temperature 57 Fe Mossbauer spectroscopy. The photo-induced colour ch…
Childhood reproduced: images of childhood represented in children's daily lives in home and day-care settings
2016
ABSTRACTThis study explores images of childhood by analysing children's pictorial representations and accompanying captions. The focus is on how children together with adults represent childhood in the home and daycare settings in a oneweek diary study. The key analytical tool was framing, which is used to highlight what kinds of images are (re)produced and narrated. The frames that emerged were (1) portrayal of the child via cultural products and societal relations, (2) portrayal of the child via individuality, relationships and attachment, (3) the child as a symbol of capabilities, and (4) the child as a learner. While illustrating how childhood was intertwined with consumption, cultural …