@misc{PrestelMoeller2015,
  author    = {Prestel, Andreas and M{\"o}ller, Heiko Michael},
  title     = {Spatio-temporal control of cellular uptake achieved by photoswitchable cell-penetrating peptides},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-89658},
  pages     = {701 -- 704},
  year      = {2015},
  abstract  = {The selective uptake of compounds into specific cells of interest is a major objective in cell biology and drug delivery. By incorporation of a novel, thermostable azobenzene moiety we generated peptides that can be switched optically between an inactive state and an active, cell-penetrating state with excellent spatio-temporal control.},
  language  = {en}
}
@misc{GuhaWarsinkeTientcheuetal.2015,
  author    = {Guha, S. and Warsinke, A. and Tientcheu, Ch. M. and Schmalz, K. and Meliani, C. and Wenger, Ch.},
  title     = {Label free sensing of creatinine using a 6 GHz CMOS near-field dielectric immunosensor},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-81177},
  year      = {2015},
  abstract  = {In this work we present a CMOS high frequency direct immunosensor operating at 6 GHz (C-band) for label free determination of creatinine. The sensor is fabricated in standard 0.13 μm SiGe:C BiCMOS process. The report also demonstrates the ability to immobilize creatinine molecules on a Si3N4 passivation layer of the standard BiCMOS/CMOS process, therefore, evading any further need of cumbersome post processing of the fabricated sensor chip. The sensor is based on capacitive detection of the amount of non-creatinine bound antibodies binding to an immobilized creatinine layer on the passivated sensor. The chip bound antibody amount in turn corresponds indirectly to the creatinine concentration used in the incubation phase. The determination of creatinine in the concentration range of 0.88-880 μM is successfully demonstrated in this work. A sensitivity of 35 MHz/10 fold increase in creatinine concentration (during incubation) at the centre frequency of 6 GHz is gained by the immunosensor. The results are compared with a standard optical measurement technique and the dynamic range and sensitivity is of the order of the established optical indication technique. The C-band immunosensor chip comprising an area of 0.3 mm2 reduces the sensing area considerably, therefore, requiring a sample volume as low as 2 μl. The small analyte sample volume and label free approach also reduce the experimental costs in addition to the low fabrication costs offered by the batch fabrication technique of CMOS/BiCMOS process.},
  language  = {en}
}
@misc{BartoloniJinMarcaidaetal.2015,
  author    = {Bartoloni, Marco and Jin, Xian and Marcaida, Maria Jos{\´e} and Banha, Joao and Dibonaventura, Ivan and Bongoni, Swathi and Bartho, Kathrin and Gr{\"a}bner, Olivia and Sefkow, Michael and Darbre, Tamis and Reymond, Jean-Louis},
  title     = {Bridged bicyclic peptides as potential drug scaffolds},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-81239},
  year      = {2015},
  abstract  = {Double cyclization of short linear peptides obtained by solid phase peptide synthesis was used to prepare bridged bicyclic peptides (BBPs) corresponding to the topology of bridged bicyclic alkanes such as norbornane. Diastereomeric norbornapeptides were investigated by 1H-NMR, X-ray crystallography and CD spectroscopy and found to represent rigid globular scaffolds stabilized by intramolecular backbone hydrogen bonds with scaffold geometries determined by the chirality of amino acid residues and sharing structural features of β-turns and α-helices. Proteome profiling by capture compound mass spectrometry (CCMS) led to the discovery of the norbornapeptide 27c binding selectively to calmodulin as an example of a BBP protein binder. This and other BBPs showed high stability towards proteolytic degradation in serum.},
  language  = {en}
}
@misc{MeyerRaberEbertetal.2015,
  author    = {Meyer, S. and Raber, G. and Ebert, Franziska and Leffers, L. and M{\"u}ller, Sandra Marie and Taleshi, M. S. and Francesconi, Kevin A. and Schwerdtle, Tanja},
  title     = {In vitro toxicological characterisation of arsenic-containing fatty acids and three of their metabolites},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-82008},
  year      = {2015},
  abstract  = {Arsenic-containing fatty acids are a group of fat-soluble arsenic species (arsenolipids) which are present in marine fish and other seafood. Recently, it has been shown that arsenic-containing hydrocarbons, another group of arsenolipids, exert toxicity in similar concentrations comparable to arsenite although the toxic modes of action differ. Hence, a risk assessment of arsenolipids is urgently needed. In this study the cellular toxicity of a saturated (AsFA 362) and an unsaturated (AsFA 388) arsenic-containing fatty acid and three of their proposed metabolites (DMAV, DMAPr and thio-DMAPr) were investigated in human liver cells (HepG2). Even though both arsenic-containing fatty acids were less toxic as compared to arsenic-containing hydrocarbons and arsenite, significant effects were observable at μM concentrations. DMAV causes effects in a similar concentration range and it could be seen that it is metabolised to its highly toxic thio analogue thio-DMAV in HepG2 cells. Nevertheless, DMAPr and thio-DMAPr did not exert any cytotoxicity. In summary, our data indicate that risks to human health related to the presence of arsenic-containing fatty acids in marine food cannot be excluded. This stresses the need for a full in vitro and in vivo toxicological characterisation of these arsenolipids.},
  language  = {en}
}
@misc{RoderHille2015,
  author    = {Roder, Phillip and Hille, Carsten},
  title     = {A Multifunctional Frontloading Approach for Repeated Recycling of a Pressure-Controlled AFM Micropipette},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-86592},
  year      = {2015},
  abstract  = {Fluid force microscopy combines the positional accuracy and force sensitivity of an atomic force microscope (AFM) with nanofluidics via a microchanneled cantilever. However, adequate loading and cleaning procedures for such AFM micropipettes are required for various application situations. Here, a new frontloading procedure is described for an AFM micropipette functioning as a force- and pressure-controlled microscale liquid dispenser. This frontloading procedure seems especially attractive when using target substances featuring high costs or low available amounts. Here, the AFM micropipette could be filled from the tip side with liquid from a previously applied droplet with a volume of only a few μL using a short low-pressure pulse. The liquid-loaded AFM micropipettes could be then applied for experiments in air or liquid environments. AFM micropipette frontloading was evaluated with the well-known organic fluorescent dye rhodamine 6G and the AlexaFluor647-labeled antibody goat anti-rat IgG as an example of a larger biological compound. After micropipette usage, specific cleaning procedures were tested. Furthermore, a storage method is described, at which the AFM micropipettes could be stored for a few hours up to several days without drying out or clogging of the microchannel. In summary, the rapid, versatile and cost-efficient frontloading and cleaning procedure for the repeated usage of a single AFM micropipette is beneficial for various application situations from specific surface modifications through to local manipulation of living cells, and provides a simplified and faster handling for already known experiments with fluid force microscopy.},
  language  = {en}
}
@misc{MegowRoehrSchmidtamBuschetal.2015,
  author    = {Megow, J{\"o}rg and R{\"o}hr, Merle I. S. and Schmidt am Busch, Marcel and Renger, Thomas and Mitrić, Roland and Kirstein, Stefan and Rabe, J{\"u}rgen P. and May, Volkhard},
  title     = {Site-dependence of van der Waals interaction explains exciton spectra of double-walled tubular J-aggregates},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-79978},
  pages     = {6741 -- 6747},
  year      = {2015},
  abstract  = {The simulation of the optical properties of supramolecular aggregates requires the development of methods, which are able to treat a large number of coupled chromophores interacting with the environment. Since it is currently not possible to treat large systems by quantum chemistry, the Frenkel exciton model is a valuable alternative. In this work we show how the Frenkel exciton model can be extended in order to explain the excitonic spectra of a specific double-walled tubular dye aggregate explicitly taking into account dispersive energy shifts of ground and excited states due to van der Waals interaction with all surrounding molecules. The experimentally observed splitting is well explained by the site-dependent energy shift of molecules placed at the inner or outer side of the double-walled tube, respectively. Therefore we can conclude that inclusion of the site-dependent dispersive effect in the theoretical description of optical properties of nanoscaled dye aggregates is mandatory.},
  language  = {en}
}
@misc{HildebrandLaschewskyWischerhoff2015,
  author    = {Hildebrand, Viet and Laschewsky, Andr{\´e} and Wischerhoff, Erik},
  title     = {Modulating the solubility of zwitterionic poly((3- methacrylamidopropyl)ammonioalkane sulfonate)s in water and aqueous salt solutions via the spacer group separating the cationic and the anionic moieties},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-103040},
  pages     = {731 -- 740},
  year      = {2015},
  abstract  = {Complementary to the well-established zwitterionic monomer 3-((3-methacrylamidopropyl)dimethylammonio) propane-1-sulfonate (SPP), the closely related monomers 2-hydroxy-3-((3-methacrylamidopropyl) dimethylammonio)propane-1-sulfonate (SHPP) and 4-((3-methacrylamidopropyl)dimethylammonio)-butane-1-sulfonate (SBP) were synthesised and polymerised by reversible addition-fragmentation chain transfer (RAFT) polymerisation, using a fluorophore labeled RAFT agent. The polyzwitterions of systematically varied molar masses were characterised with respect to their solubility in water and aqueous salt solutions. Both poly(sulfobetaine)s show thermoresponsive behaviour in water, exhibiting phase separation at low temperatures and upper critical solution temperatures (UCST). For both polySHPP and polySBP, cloud points depend notably on the molar mass, and are much higher in D2O than in H2O. Also, the cloud points are effectively modulated by the addition of salts. The individual effects can be in parts correlated to the Hofmeister series for the anions studied. Still, they depend in a complex way on the concentration and the nature of the added electrolytes, on the one hand, and on the detailed nature of the spacer group separating the anionic and the cationic charges of the betaine moiety, on the other hand. As anticipated, the cloud points of polySBP are much higher than the ones of the analogous polySPP of identical molar mass. Surprisingly, the cloud points of polySHPP are also somewhat higher than the ones of their polySPP analogues, despite the additional hydrophilic hydroxyl group present in the spacer separating the ammonium and the sulfonate moieties. These findings point to a complicated interplay of the various hydrophilic components in polyzwitterions with respect to their overall hydrophilicity. Thus, the spacer group in the betaine moiety proves to be an effective additional molecular design parameter, apparently small variations of which strongly influence the phase behaviour of the polyzwitterions in specific aqueous environments.},
  language  = {en}
}
@misc{PapeWessigBrunner2015,
  author    = {Pape, Simon and Wessig, Pablo and Brunner, Heiko},
  title     = {A new and environmentally benign synthesis of aroylguanidines using iron trichloride},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-102720},
  pages     = {101408 -- 101411},
  year      = {2015},
  abstract  = {A new synthetic approach for the guanylation of aroylthioureas using iron trichloride is presented. Our synthetic method distinguishes itself by benign reaction conditions, low costs and a broad product spectrum. The scope of the reaction and calorimetric studies are described.},
  language  = {en}
}
@misc{KumkeKlier2015,
  author    = {Kumke, Michael Uwe and Klier, Dennis Tobias},
  title     = {Upconversion NaYF4:Yb:Er nanoparticles co-doped with Gd3+ and Nd3+ for thermometry on the nanoscale},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-102677},
  pages     = {67149 -- 67156},
  year      = {2015},
  abstract  = {In the present work, the upconversion luminescence properties of oleic acid capped NaYF4:Gd3+:Yb3+:Er3+ upconversion nanoparticles (UCNP) with pure β crystal phase and Nd3+ ions as an additional sensitizer were studied in the temperature range of 288 K < T < 328 K. The results of this study showed that the complex interplay of different mechanisms and effects, causing the special temperature behavior of the UCNP can be developed into thermometry on the nanoscale, e.g. to be applied in biological systems on a cellular level. The performance was improved by the use of Nd3+ as an additional dopant utilizing the cascade sensitization mechanism in tri-doped UCNP.},
  language  = {en}
}
@phdthesis{Jehannin2015,
  author    = {Jehannin, Marie},
  title     = {About the role of physico-chemical properties and hydrodynamics on the progress of a precipitation reaction},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-88364},
  school      = {Universit{\"a}t Potsdam},
  pages     = {xii, 130},
  year      = {2015},
  abstract  = {The size and morphology control of precipitated solid particles is a major economic issue for numerous industries. For instance, it is interesting for the nuclear industry, concerning the recovery of radioactive species from used nuclear fuel. The precipitates features, which are a key parameter from the post-precipitate processing, depend on the process local mixing conditions. So far, the relationship between precipitation features and hydrodynamic conditions have not been investigated. In this study, a new experimental configuration consisting of coalescing drops is set to investigate the link between reactive crystallization and hydrodynamics. Two configurations of aqueous drops are examined. The first one corresponds to high contact angle drops (>90°) in oil, as a model system for flowing drops, the second one correspond to sessile drops in air with low contact angle (<25°). In both cases, one reactive is dissolved in each drop, namely oxalic acid and cerium nitrate. When both drops get into contact, they may coalesce; the dissolved species mix and react to produce insoluble cerium oxalate. The precipitates features and effect on hydrodynamics are investigated depending on the solvent. In the case of sessile drops in air, the surface tension difference between the drops generates a gradient which induces a Marangoni flow from the low surface tension drop over the high surface tension drop. By setting the surface tension difference between the two drops and thus the Marangoni flow, the hydrodynamics conditions during the drop coalescence could be modified. Diols/water mixtures are used as solvent, in order to fix the surface tension difference between the liquids of both drops regardless from the reactant concentration. More precisely, the used diols, 1,2-propanediol and 1,3-propanediol, are isomer with identical density and close viscosity. By keeping the water volume fraction constant and playing with the 1,2-propanediol and 1,3-propanediol volume fractions of the solvents, the mixtures surface tensions differ up to 10 mN/m for identical/constant reactant concentration, density and viscosity. 3 precipitation behaviors were identified for the coalescence of water/diols/recatants drops depending on the oxalic excess. The corresponding precipitates patterns are visualized by optical microscopy and the precipitates are characterized by confocal microscopy SEM, XRD and SAXS measurements. In the intermediate oxalic excess regime, formation of periodic patterns can be observed. These patterns consist in alternating cerium oxalate precipitates with distinct morphologies, namely needles and "microflowers". Such periodic fringes can be explained by a feedback mechanism between convection, reaction and the diffusion.},
  language  = {en}
}