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121.
More than one century ago, Lippmann found that capillary forces can be effectively controlled by external electrostatic forces. As a simple example, by applying a voltage between a conducting liquid droplet and the surface it is sitting on we are able to adjust the wetting angle of the drop. Since Lippmann's findings, electrocapillary phenomena – or electrowetting – have developed into a series of tools for manipulating microdroplets on solid surfaces, or small amounts of liquids in capillaries for microfluidic applications. In this article, we briefly review some recent progress of fundamental understanding of electrowetting and address some still unsolved issues. Specifically, we focus on static and dynamic electrowetting. In static electrowetting, we discuss some basic phenomena found in DC and AC electrowetting, and some theories about the origin of contact angle saturation. In dynamic electrowetting, we introduce some studies about this rather recent area. At last, we address some other capillary phenomena governed by electrostatics and we give an outlook that might stimulate further investigations on electrowetting. 相似文献
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Dieter Sellmann Elmar Jonk Hans -Jürgen Reinecke und Thomas Würminghausen 《Fresenius' Journal of Analytical Chemistry》1979,294(5):372-374
Zusammenfassung Es wird eine Apparatur für die HPLC beschrieben, mit der sich thermolabile Verbindungen bei Temperaturen bis zu –80° C trennen lassen. Die präparative Trennung der physikalisch praktisch identischen Moleküle C5H5Mn(CO)2N2 und C5H5Mn(CO)3 wird bei –15° C erreicht.
Low-temperature high-pressure liquid chromatography of thermolabile compounds: Separation of C5H5Mn(CO)2N2 and C5H5Mn(CO)3
Summary A HPLC device for the separation of thermolabile compounds at temperatures down to –80° C is described. The separation of the physically practically identical molecules C5H5Mn(CO)2N2 and C5H5Mn(CO)3 is achieved on a preparative scale at –15° C.相似文献
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Basarić N Horvat M Mlinarić-Majerski K Zimmermann E Neudörfl J Griesbeck AG 《Organic letters》2008,10(18):3965-3968
The photochemical reaction of N-(1-adamantyl)phthalimide (1) gives cleanly one product, the novel hexacyclic benzazepine derivative of 2,4-methanoadamantane 2. Its structure was characterized by spectroscopic methods and X-ray analysis and represent the first example of the 2-azahexacyclo[8.7.1.1 (1,4).0 (4,9).0 (11,16).0 (12,18)]nonadeca-4,6,8-triene skeleton. The product is formed by a domino process of two consecutive excited-state intramolecular gamma-hydrogen-transfer reactions. Base hydrolysis of the benzazepine 2 gives in high yield the keto derivative of the 1,2-substituted adamantane epsilon-amino acid 3. 相似文献
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Lucas Willmann Manuel Schlimpert Marc Hirschfeld Thalia Erbes Hans Neubauer Elmar Stickeler Bernd Kammerer 《Analytica chimica acta》2016
In recent years, knowledge about metabolite changes which are characteristic for the physiologic state of cancer cells has been acquired by liquid chromatography coupled to mass spectrometry. Distinct molecularly characterized breast cancer cell lines provide an unbiased and standardized in vitro tumor model reflecting the heterogeneity of the disease. Tandem mass spectrometry is a widely applied analytical platform and highly sensitive technique for analysis of complex biological samples. Endo- and exometabolite analysis of the breast cancer cell lines MDA-MB-231, -453 and BT-474 as well as the breast epithelial cell line MCF-10A has been performed using two different analytical platforms: UPLC-ESI-Q-TOF based on a scheduled precursor list has been applied for highlighting of significant differences between cell lines and HPLC-ESI-QqQ using multiple reaction monitoring has been utilized for a targeted approach focusing on RNA metabolism and interconnected pathways, respectively. Statistical analysis enabled a clear discrimination of the breast epithelial from the breast cancer cell lines. As an effect of oxidative stress, a decreased GSH/GSSG ratio has been detected in breast cancer cell lines. The triple negative breast cancer cell line MDA-MB-231 showed an elevation in nicotinamide, 1-ribosyl-nicotinamide and NAD+ reflecting the increased energy demand in triple negative breast cancer, which has a more aggressive clinical course than other forms of breast cancer. Obtained distinct metabolite pattern could be correlated with distinct molecular characteristics of breast cancer cells. Results and methodology of this preliminary in vitro study could be transferred to in vivo studies with breast cancer patients. 相似文献