@article{PauliGlotzbachSchoonAndreattaetal.2013, author = {Pauli, Paul and Glotzbach-Schoon, Evelyn and Andreatta, Marta and Reif, Andreas and Ewald, Heike and Tr{\"o}ger, Christian and Baumann, Christian and Deckert, J{\"u}rgen and M{\"u}hlberger, Andreas}, title = {Contextual fear conditioning in virtual reality is affected by 5HTTLPR and NPSR1 polymorphisms: effects on fear-potentiated startle}, series = {Frontiers in Behavioral Neuroscience}, journal = {Frontiers in Behavioral Neuroscience}, doi = {10.3389/fnbeh.2013.00031}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-96516}, year = {2013}, abstract = {The serotonin (5-HT) and neuropeptide S (NPS) systems are discussed as important genetic modulators of fear and sustained anxiety contributing to the etiology of anxiety disorders. Sustained anxiety is a crucial characteristic of most anxiety disorders which likely develops through contextual fear conditioning. This study investigated if and how genetic alterations of the 5-HT and the NPS systems as well as their interaction modulate contextual fear conditioning; specifically, function polymorphic variants in the genes coding for the 5-HT transporter (5HTT) and the NPS receptor (NPSR1) were studied. A large group of healthy volunteers was therefore stratified for 5HTTLPR (S+ vs. LL carriers) and NPSR1 rs324981 (T+ vs. AA carriers) polymorphisms resulting in four genotype groups (S+/T+, S+/AA, LL/T+, LL/AA) of 20 participants each. All participants underwent contextual fear conditioning and extinction using a virtual reality (VR) paradigm. During acquisition, one virtual office room (anxiety context, CXT+) was paired with an unpredictable electric stimulus (unconditioned stimulus, US), whereas another virtual office room was not paired with any US (safety context, CXT-). During extinction no US was administered. Anxiety responses were quantified by fear-potentiated startle and ratings. Most importantly, we found a gene × gene interaction on fear-potentiated startle. Only carriers of both risk alleles (S+/T+) exhibited higher startle responses in CXT+ compared to CXT-. In contrast, anxiety ratings were only influenced by the NPSR1 polymorphism with AA carriers showing higher anxiety ratings in CXT+ as compared to CXT-. Our results speak in favor of a two level account of fear conditioning with diverging effects on implicit vs. explicit fear responses. Enhanced contextual fear conditioning as reflected in potentiated startle responses may be an endophenotype for anxiety disorders.}, language = {en} } @article{WeberScholzDomschkeetal.2012, author = {Weber, Heike and Scholz, Claus J{\"u}rgen and Domschke, Katharina and Baumann, Christian and Klauke, Benedikt and Jacob, Christian P. and Maier, Wolfgang and Fritze, J{\"u}rgen and Bandelow, Borwin and Zwanzger, Peter Michael and Lang, Thomas and Fehm, Lydia and Str{\"o}hle, Andreas and Hamm, Alfons and Gerlach, Alexander L. and Alpers, Georg W. and Kircher, Tilo and Wittchen, Hans-Ulrich and Arolt, Volker and Pauli, Paul and Deckert, J{\"u}rgen and Reif, Andreas}, title = {Gender Differences in Associations of Glutamate Decarboxylase 1 Gene (GAD1) Variants with Panic Disorder}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-75830}, year = {2012}, abstract = {Background: Panic disorder is common (5\% prevalence) and females are twice as likely to be affected as males. The heritable component of panic disorder is estimated at 48\%. Glutamic acid dehydrogenase GAD1, the key enzyme for the synthesis of the inhibitory and anxiolytic neurotransmitter GABA, is supposed to influence various mental disorders, including mood and anxiety disorders. In a recent association study in depression, which is highly comorbid with panic disorder, GAD1 risk allele associations were restricted to females. Methodology/Principal Findings: Nineteen single nucleotide polymorphisms (SNPs) tagging the common variation in GAD1 were genotyped in two independent gender and age matched case-control samples (discovery sample n = 478; replication sample n = 584). Thirteen SNPs passed quality control and were examined for gender-specific enrichment of risk alleles associated with panic disorder by using logistic regression including a genotype6gender interaction term. The latter was found to be nominally significant for four SNPs (rs1978340, rs3762555, rs3749034, rs2241165) in the discovery sample; of note, the respective minor/risk alleles were associated with panic disorder only in females. These findings were not confirmed in the replication sample; however, the genotype6gender interaction of rs3749034 remained significant in the combined sample. Furthermore, this polymorphism showed a nominally significant association with the Agoraphobic Cognitions Questionnaire sum score. Conclusions/Significance: The present study represents the first systematic evaluation of gender-specific enrichment of risk alleles of the common SNP variation in the panic disorder candidate gene GAD1. Our tentative results provide a possible explanation for the higher susceptibility of females to panic disorder.}, subject = {Medizin}, language = {en} } @article{HarterHaukeHeitzetal.2017, author = {Harter, Philipp and Hauke, Jan and Heitz, Florian and Reuss, Alexander and Kommoss, Stefan and Marm{\´e}, Frederik and Heimbach, Andr{\´e} and Prieske, Katharina and Richters, Lisa and Burges, Alexander and Neidhardt, Guido and de Gregorio, Nikolaus and El-Balat, Ahmed and Hilpert, Felix and Meier, Werner and Kimmig, Rainer and Kast, Karin and Sehouli, Jalid and Baumann, Klaus and Jackisch, Christian and Park-Simon, Tjoung-Won and Hanker, Lars and Kr{\"o}ber, Sandra and Pfisterer, Jacobus and Gevensleben, Heidrun and Schnelzer, Andreas and Dietrich, Dimo and Neunh{\"o}ffer, Tanja and Krockenberger, Mathias and Brucker, Sara Y. and N{\"u}rnberg, Peter and Thiele, Holger and Altm{\"u}ller, Janine and Lamla, Josefin and Elser, Gabriele and du Bois, Andreas and Hahnen, Eric and Schmutzler, Rita}, title = {Prevalence of deleterious germline variants in risk genes including \(BRCA1/2\) in consecutive ovarian cancer patients (AGO-TR-1)}, series = {PLoS ONE}, volume = {12}, journal = {PLoS ONE}, number = {10}, doi = {10.1371/journal.pone.0186043}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-173553}, year = {2017}, abstract = {Background Identification of families at risk for ovarian cancer offers the opportunity to consider prophylactic surgery thus reducing ovarian cancer mortality. So far, identification of potentially affected families in Germany was solely performed via family history and numbers of affected family members with breast or ovarian cancer. However, neither the prevalence of deleterious variants in \(BRCA1/2\) in ovarian cancer in Germany nor the reliability of family history as trigger for genetic counselling has ever been evaluated. Methods Prospective counseling and germline testing of consecutive patients with primary diagnosis or with platinum-sensitive relapse of an invasive epithelial ovarian cancer. Testing included 25 candidate and established risk genes. Among these 25 genes, 16 genes (\(ATM\), \(BRCA1\), \(BRCA2\), \(CDH1\), \(CHEK2\), \(MLH1\), \(MSH2\), \(MSH6\), \(NBN\), \(PMS2\), \(PTEN\), \(PALB2\), \(RAD51C\), \(RAD51D\), \(STK11\), \(TP53\)) were defined as established cancer risk genes. A positive family history was defined as at least one relative with breast cancer or ovarian cancer or breast cancer in personal history. Results In total, we analyzed 523 patients: 281 patients with primary diagnosis of ovarian cancer and 242 patients with relapsed disease. Median age at primary diagnosis was 58 years (range 16-93) and 406 patients (77.6\%) had a high-grade serous ovarian cancer. In total, 27.9\% of the patients showed at least one deleterious variant in all 25 investigated genes and 26.4\% in the defined 16 risk genes. Deleterious variants were most prevalent in the \(BRCA1\) (15.5\%), \(BRCA2\) (5.5\%), \(RAD51C\) (2.5\%) and \(PALB2\) (1.1\%) genes. The prevalence of deleterious variants did not differ significantly between patients at primary diagnosis and relapse. The prevalence of deleterious variants in \(BRCA1/2\) (and in all 16 risk genes) in patients <60 years was 30.2\% (33.2\%) versus 10.6\% (18.9\%) in patients \(\geq\)60 years. Family history was positive in 43\% of all patients. Patients with a positive family history had a prevalence of deleterious variants of 31.6\% (36.0\%) versus 11.4\% (17.6\%) and histologic subtype of high grade serous ovarian cancer versus other showed a prevalence of deleterious variants of 23.2\% (29.1\%) and 10.2\% (14.8\%), respectively. Testing only for \(BRCA1/2\) would miss in our series more than 5\% of the patients with a deleterious variant in established risk genes. Conclusions 26.4\% of all patients harbor at least one deleterious variant in established risk genes. The threshold of 10\% mutation rate which is accepted for reimbursement by health care providers in Germany was observed in all subgroups analyzed and neither age at primary diagnosis nor histo-type or family history sufficiently enough could identify a subgroup not eligible for genetic counselling and testing. Genetic testing should therefore be offered to every patient with invasive epithelial ovarian cancer and limiting testing to \(BRCA1/2\) seems to be not sufficient.}, language = {en} } @article{KiermaschRiederTvingstedtetal.2016, author = {Kiermasch, David and Rieder, Philipp and Tvingstedt, Kristofer and Baumann, Andreas and Dyakonov, Vladimir}, title = {Improved charge carrier lifetime in planar perovskite solar cells by bromine doping}, series = {Scientific Reports}, volume = {6}, journal = {Scientific Reports}, doi = {10.1038/srep39333}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-147976}, pages = {39333}, year = {2016}, abstract = {The charge carrier lifetime is an important parameter in solar cells as it defines, together with the mobility, the diffusion length of the charge carriers, thus directly determining the optimal active layer thickness of a device. Herein, we report on charge carrier lifetime values in bromine doped planar methylammonium lead iodide (MAPbI\(_3\)) solar cells determined by transient photovoltage. The corresponding charge carrier density has been derived from charge carrier extraction. We found increased lifetime values in solar cells incorporating bromine compared to pure MAPbI\(_3\) by a factor of ~2.75 at an illumination intensity corresponding to 1 sun. In the bromine containing solar cells we additionally observe an anomalously high value of extracted charge, which we deduce to originate from mobile ions.}, language = {en} } @phdthesis{Baumann2011, author = {Baumann, Andreas}, title = {Charge Transport and Recombination Dynamics in Organic Bulk Heterojunction Solar Cells}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-64915}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2011}, abstract = {The charge transport in disordered organic bulk heterojunction (BHJ) solar cells is a crucial process affecting the power conversion efficiency (PCE) of the solar cell. With the need of synthesizing new materials for improving the power conversion efficiency of those cells it is important to study not only the photophysical but also the electrical properties of the new material classes. Thereby, the experimental techniques need to be applicable to operating solar cells. In this work, the conventional methods of transient photoconductivity (also known as "Time-of-Flight" (TOF)), as well as the transient charge extraction technique of "Charge Carrier Extraction by Linearly Increasing Voltage" (CELIV) are performed on different organic blend compositions. Especially with the latter it is feasible to study the dynamics, i.e. charge transport and charge carrier recombination, in bulk heterojunction (BHJ) solar cells with active layer thicknesses of 100-200 nm. For a well performing organic BHJ solar cells the morphology is the most crucial parameter finding a trade-off between an efficient photogeneration of charge carriers and the transport of the latter to the electrodes. Besides the morphology, the nature of energetic disorder of the active material blend and its influence on the dynamics are discussed extensively in this work. Thereby, the material system of poly(3-hexylthiophene-2,5-diyl) (P3HT) and [6,6]-phenyl-C61 butyric acid methyl ester (PC61BM) serves mainly as a reference material system. New promising donor or acceptor materials and their potential for application in organic photovoltaics are studied in view of charge dynamics and compared with the reference system. With the need for commercialization of organic solar cells the question of the impact of environmental conditions on the PCE of the solar cells raises. In this work, organic BHJ solar cells exposed to synthetic air for finite duration are studied in view of the charge carrier transport and recombination dynamics. Finally, within the framework of this work the technique of photo-CELIV is improved. With the modified technique it is now feasible to study the mobility and lifetime of charge carriers in organic solar cells under operating conditions.}, subject = {Photovoltaik}, language = {en} } @article{TvingstedtMalinkiewiczBaumannetal.2014, author = {Tvingstedt, Kristofer and Malinkiewicz, Olga and Baumann, Andreas and Deibel, Carsten and Snaith, Henry J. and Dyakonov, Vladimir and Bolink, Henk J.}, title = {Radiative efficiency of lead iodide based perovskite solar cells}, series = {Scientific Reports}, volume = {4}, journal = {Scientific Reports}, doi = {10.1038/srep06071}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-119360}, pages = {6071}, year = {2014}, abstract = {The maximum efficiency of any solar cell can be evaluated in terms of its corresponding ability to emit light. We herein determine the important figure of merit of radiative efficiency for Methylammonium Lead Iodide perovskite solar cells and, to put in context, relate it to an organic photovoltaic (OPV) model device. We evaluate the reciprocity relation between electroluminescence and photovoltaic quantum efficiency and conclude that the emission from the perovskite devices is dominated by a sharp band-to-band transition that has a radiative efficiency much higher than that of an average OPV device. As a consequence, the perovskite have the benefit of retaining an open circuit voltage ~0.14 V closer to its radiative limit than the OPV cell. Additionally, and in contrast to OPVs, we show that the photoluminescence of the perovskite solar cell is substantially quenched under short circuit conditions in accordance with how an ideal photovoltaic cell should operate.}, language = {en} } @article{KiermaschFischerGilEscrigetal.2021, author = {Kiermasch, David and Fischer, Mathias and Gil-Escrig, Lid{\´o}n and Baumann, Andreas and Bolink, Henk J. and Dyakonov, Vladimir and Tvingstedt, Kristofer}, title = {Reduced Recombination Losses in Evaporated Perovskite Solar Cells by Postfabrication Treatment}, series = {Solar RRL}, volume = {5}, journal = {Solar RRL}, number = {11}, doi = {10.1002/solr.202100400}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-258003}, year = {2021}, abstract = {The photovoltaic perovskite research community has now developed a large set of tools and techniques to improve the power conversion efficiency (PCE). One such arcane trick is to allow the finished devices to dwell in time, and the PCE often improves. Herein, a mild postannealing procedure is implemented on coevaporated perovskite solar cells confirming a substantial PCE improvement, mainly attributed to an increased open-circuit voltage (V\(_{OC}\)). From a V\(_{OC}\) of around 1.11 V directly after preparation, the voltage improves to more than 1.18 V by temporal and thermal annealing. To clarify the origin of this annealing effect, an in-depth device experimental and simulation characterization is conducted. A simultaneous reduction of the dark saturation current, the ideality factor (n\(_{id}\)), and the leakage current is revealed, signifying a substantial impact of the postannealing procedure on recombination losses. To investigate the carrier dynamics in more detail, a set of transient optoelectrical methods is first evaluated, ascertaining that the bulk carrier lifetime is increased with device annealing. Second, a drift-diffusion simulation is used, confirming that the beneficial effect of the annealing has its origin in effective bulk trap passivation that accordingly leads to a reduction of Shockley-Read-Hall recombination rates.}, language = {en} }