Technical University of Dortmund

About: Technical University of Dortmund is a education organization based out in Dortmund, Nordrhein-Westfalen, Germany. It is known for research contribution in the topics: Large Hadron Collider & Neutrino. The organization has 13028 authors who have published 27666 publications receiving 615557 citations. The organization is also known as: Dortmund University & University of Dortmund.

Very high energy gamma-ray radiation from the stellar mass black hole binary cygnus X-1

Abstract: We report on the results from the observations in the very high energy band ( VHE; GeV) of the black E = 100 g hole X- ray binary ( BHXB) Cygnus X- 1. The observations were performed with the MAGIC telescope, for a total of 40 hr during 26 nights, spanning the period between 2006 June and November. Searches for steady gamma - ray signals yielded no positive result, and upper limits to the integral flux ranging between 1% and 2% of the Crab Nebula flux, depending on the energy, have been established. We also analyzed each observation night independently, obtaining evidence of gamma- ray signals at the 4.0 j significance level ( 3.2 j after trial correction) for 154 minutes of effective on- time ( EOT) on September 24 between 20: 58 and 23: 41 UTC, coinciding with an X- ray flare seen by RXTE, Swift, and INTEGRAL. A search for faster- varying signals within a night resulted in an excess with a significance of 4.9 j ( 4.1 j after trial correction) for 79 minutes EOT between 22: 17 and 23: 41 UTC. The measured excess is compatible with a pointlike source at the position of Cygnus X- 1 and excludes the nearby radio nebula powered by its relativistic jet. The differential energy spectrum is well fitted by an unbroken power law described as dN/(dA dt dE) = ( 2.3 +/- 0.6)* 10 ( E/1TeV). This is the first experimental evidence of VHE emission from a stellar mass black hole and therefore from a confirmed accreting X- ray binary.

Relevance of the deletion polymorphisms of the glutathione S-transferases GSTT1 and GSTM1 in pharmacology and toxicology.

Abstract: Although cytosolic glutathione S-transferase (GST) enzymes occupy a key position in biological detoxification processes, two of the most relevant human isoenzymes, GSTT1-1 and GSTM1-1, are genetically deleted (non-functional alleles GSTT1*0 and GSTM1*0) in a high percentage of the human population, with major ethnic differences. The structures of the GSTT and GSTM gene areas explain the underlying genetic processes. GSTT1-1 is highly conserved during evolution and plays a major role in phase-II biotransformation of a number of drugs and industrial chemicals, e.g. cytostatic drugs, hydrocarbons and halogenated hydrocarbons. GSTM1-1 is particularly relevant in the deactivation of carcinogenic intermediates of polycyclic aromatic hydrocarbons. Several lines of evidence suggest that hGSTT1-1 and/or hGSTM1-1 play a role in the deactivation of reactive oxygen species that are likely to be involved in cellular processes of inflammation, ageing and degenerative diseases. There is cumulating evidence that combinations of the GSTM1*0 state with other genetic traits affecting the metabolism of carcinogens (CYP1A1, GSTP1) may predispose the aero-digestive tract and lung, especially in smokers, to a higher risk of cancer. The GSTM1*0 status appears also associated with a modest increase in the risk of bladder cancer, consistent with a GSTM1 interaction with carcinogenic tobacco smoke constituents. Both human GST deletions, although largely counterbalanced by overlapping substrate affinities within the GST superfamily, have consequences when the organism comes into contact with distinct man-made chemicals. This appears relevant in industrial toxicology and in drug metabolism.

Modeling of aqueous electrolyte solutions with perturbed-chain statistical associated fluid theory

Abstract: The vapor pressures and liquid densities of single-salt electrolyte solutions containing NaCl, LiCl, KCl, NaBr, LiBr, KBr, NaI, LiI, KI, Li2SO4, Na2SO4, and K2SO4 were modeled with an equation of state based on perturbed-chain statistical associated fluid theory (PC-SAFT). The PC-SAFT model was extended to charged compounds using a Debye−Huckel term for the electrostatic interactions. Two model parameters for each ion were fitted to experimental pVT and vapor-pressure data. The model is able to excellently reproduce the experimental data up to high salt molalities and even to predict vapor pressures in mixed-salt solutions.

Aspergillus fumigatus Fresenius, an endophytic fungus from Juniperus communis L. Horstmann as a novel source of the anticancer pro-drug deoxypodophyllotoxin.

Abstract: Aims: Isolation, identification and characterization of an endophytic fungus from Juniperus communis L. Horstmann, as a novel producer of deoxypodophyllotoxin and its in vitro antimicrobial assay. Methods and Results: The methodology for the isolation, identification and characterization of a novel endophytic fungus from the twigs of the J. communis L. Horstmann plant, which specifically and consistently produces deoxypodophyllotoxin, was unequivocally established. The fungus was identified as Aspergillus fumigatus Fresenius by molecular, morphological and physiological methods. Deoxypodophyllotoxin was identified and quantified by high-resolution LC-MS, LC-MS2 and LC-MS3. The antimicrobial efficacy of the fungal deoxypodophyllotoxin against a panel of pathogenic bacteria was established. Conclusions: The production of deoxypodophyllotoxin (found in the host) by the cultured endophyte is an enigmatic observation. It demonstrates the transfer of gene(s) for such accumulation by horizontal means from the host plant to its endophytic counterpart. It would be interesting to further study the deoxypodophyllotoxin production and regulation by the cultured endophyte in J. communis and in axenic cultures. Significance and Impact of the Study: This endophyte is a potential handle for scientific and commercial exploitation. Although the current accumulation of deoxypodophyllotoxin by the endophyte is not very high, it could be scaled-up to provide adequate production to satisfy new drug development and clinical needs. However, further refined precursor-feeding and mass-balance studies are required to result in the consistent and dependable production.

Mutational dynamics between primary and relapse neuroblastomas

Abstract: Neuroblastoma is a malignancy of the developing sympathetic nervous system that is often lethal when relapse occurs. We here used whole-exome sequencing, mRNA expression profiling, array CGH and DNA methylation analysis to characterize 16 paired samples at diagnosis and relapse from individuals with neuroblastoma. The mutational burden significantly increased in relapsing tumors, accompanied by altered mutational signatures and reduced subclonal heterogeneity. Global allele frequencies at relapse indicated clonal mutation selection during disease progression. Promoter methylation patterns were consistent over disease course and were patient specific. Recurrent alterations at relapse included mutations in the putative CHD5 neuroblastoma tumor suppressor, chromosome 9p losses, DOCK8 mutations, inactivating mutations in PTPN14 and a relapse-specific activity pattern for the PTPN14 target YAP. Recurrent new mutations in HRAS, KRAS and genes mediating cell-cell interaction in 13 of 16 relapse tumors indicate disturbances in signaling pathways mediating mesenchymal transition. Our data shed light on genetic alteration frequency, identity and evolution in neuroblastoma.