University of Erlangen-Nuremberg

About: University of Erlangen-Nuremberg is a education organization based out in Erlangen, Bayern, Germany. It is known for research contribution in the topics: Population & Immune system. The organization has 42405 authors who have published 85600 publications receiving 2663922 citations.

TiO2 nanotubes and their application in dye-sensitized solar cells

Abstract: The present article reviews the current status of using TiO2 nanotubes in Gratzel-type, dye-sensitized solar cells and extends the overview with the latest results and findings. Critical factors in tube geometry (length, diameter, top morphology), crystal structure (amorphous, anatase, rutile) as well as factors affecting dye loading or electron mobility are addressed. The highest solar cell efficiencies today for pure nanotube systems reach approximately 4% while for some mixed systems, around 7% has been reported. For both systems significant room for enhancement is anticipated and some key points and strategies for improvement are outlined.

Endohedral fullerenes for organic photovoltaic devices

Abstract: A limiting factor of the power conversion efficiencies of organic photovoltaic devices is low voltage output Methano derivatives of the trimetallic endohedral fullerene Lu3N@C80 have now been synthesized and used as the acceptor in organic photovoltaics The open circuit voltage of the devices is significantly above those made using alternative fullerenes So far, one of the fundamental limitations of organic photovoltaic (OPV) device power conversion efficiencies (PCEs) has been the low voltage output caused by a molecular orbital mismatch between the donor polymer and acceptor molecules Here, we present a means of addressing the low voltage output by introducing novel trimetallic nitride endohedral fullerenes (TNEFs) as acceptor materials for use in photovoltaic devices TNEFs were discovered in 1999 by Stevenson et al 1; for the first time derivatives of the TNEF acceptor, Lu3N@C80, are synthesized and integrated into OPV devices The reduced energy offset of the molecular orbitals of Lu3N@C80 to the donor, poly(3-hexyl)thiophene (P3HT), reduces energy losses in the charge transfer process and increases the open circuit voltage (Voc) to 260 mV above reference devices made with [6,6]-phenyl-C61-butyric methyl ester (C60-PCBM) acceptor PCEs >4% have been observed using P3HT as the donor material This work clears a path towards higher PCEs in OPV devices by demonstrating that high-yield charge separation can occur with OPV systems that have a reduced donor/acceptor lowest unoccupied molecular orbital energy offset

Patterns of cortical reorganization in complex regional pain syndrome

Abstract: Objective To use magnetoencephalography to assess possible cortical reorganization in the primary somatosensory cortex (S1) of patients with complex regional pain syndrome (CRPS). Background Patterns of pain and sensory symptoms in CRPS may indicate plastic changes of the CNS. Methods Magnetic source imaging was used to explore changes in the cortical representation of digits (D) 1 and 5 in relation to the lower lip on the unaffected and affected CRPS side in 12 patients. Results The authors found a significant shrinkage of the extension of the cortical hand representation for the CRPS affected side. The center of the hand was shifted toward the cortical representation of the lip. The cortical reorganization correlated with the amount of CRPS pain (r = 0.792), as measured by the McGill questionnaire, and the extent of mechanical hyperalgesia (r = 0.860). Using multiple regression analysis, the best predictor for the plastic changes was found to be mechanical hyperalgesia. Additionally, S1 sources following tactile stimulation were significantly increased on the CRPS side compared to the unaffected limb. Conclusions This study showed reorganization of the S1 cortex contralateral to the CRPS affected side. The reorganization appeared to be linked to complaints of neuropathic pain.

Multiple choice vocabulary test MWT as a valid and short test to estimate premorbid intelligence

Abstract: The discrepancy between current and premorbid ability is a relevant indicator of acquired mental impairment, which itself is closely related to general cerebral dysfunction. The use of tests sensitive to cerebral dysfunction, raises relatively few problems compared with tests being resistant that are used to estimate premorbid mental ability. For premorbid ability, verbal tests assessing knowledge, especially vocabulary, have been shown to be valid. A test, possibly more insensitive to brain dysfunction than the ones usually administered, is the multiple choice vocabulary test (MWT = Mehrfachwahl-Wortschatz-Test). At present only German versions are available. They are presented in some detail because of their advantages. Construction of the MWT is simple, and it can be easily administered in about five minutes. The results correlate fairly well with global IQ in healthy adults (median of r = 0.72 in 22 samples) and are more insensitive to current disturbances than such tests as the WAIS vocabulary test. The limitations of premorbid tests with respect to diagnostic validity are discussed. It is concluded, that studies which do not control premorbid intelligence have to be considered as a "malpractice" and should not be accepted by scientists.