20 research outputs found

    A tool for determination of the three-dimensional orientation of electronic transition dipole moments and identification of configurational isomers

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    A method is presented that combines femtosecondpolarization resolved UV/visible pump–IR probe spectroscopy and density functional theory calculations in determining the three-dimensional orientation of an electronic transition dipole moment (tdm) within the molecular structure. The method is demonstrated on the approximately planar molecule coumarin 314 (C314) dissolved in acetonitrile, which can exist in two ground state configurations: the E- and the Z-isomer. Based on an exhaustive search analysis on polarization resolved measurement data for four different vibrational modes, it is concluded that C314 in acetonitrile is the E-isomer. The electronic tdm vector for the electronic S0→S1 transition is determined and the analysis shows that performing the procedure for four vibrational modes instead of the minimally required three reduces the 1σ probability area from 2.34% to 2.24% of the solution space. Moreover, the fastest rotational correlation timeτc for the C314 E-isomer is determined to be 26±2 ps

    An angle balanced polarization resolved femtosecond VIS pump–IR probe study

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    Photoisomerization of biliverdin (BV) chromophore triggers the photoresponse in native Agp1 bacteriophytochrome. We discuss heterogeneity in phytochrome Pr form to account for the shape of the absorption profile. We investigated different regions of the absorption profile by angle balanced polarization resolved femtosecond VIS pump–IR probe spectroscopy. We studied the Pr form of Agp1 with its natural chromophore and with a sterically locked 18Et-BV (locked Agp1). We followed the dynamics and orientations of the carbonyl stretching vibrations of ring D and ring A in their ground and electronically excited states. Photoisomerization of ring D is reflected by strong signals of the ring D carbonyl vibration. In contrast, orientational data on ring A show no rotation of ring A upon photoexcitation. Orientational data allow excluding a ZZZasa geometry and corroborates a nontwisted ZZZssa geometry of the chromophore. We found no proof for heterogeneity but identified a new, to our knowledge, electronic transition in the absorption profile at 644 nm (S0→S2). Excitation of the S0→S2 transition will introduce a more complex photodynamics compared with S0→S1 transition. Our approach provides fundamental information on disentanglement of absorption profiles, identification of chromophore structures, and determination of molecular groups involved in the photoisomerization process of photoreceptors

    Bovine tuberculosis and brucellosis in cattle and African buffalo in the Limpopo National Park, Mozambique

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    Bovine tuberculosis (BTB) and brucellosis are prevalent in buffaloes of the Kruger National Park (KNP, South Africa). Both diseases were considered to have no or a very low prevalence in wildlife and livestock in and around the Limpopo National Park (LNP, Mozambique). The same applies for tuberculosis in Gonarezhou National Park (GNP, Zimbabwe), but just recently, BTB was detected in buffaloes in the GNP and fears arose that the disease might also spread to the LNP as a result of the partial removal of the fences between the three parks to form the Great Limpopo Transfrontier Park. To assess the status of both diseases in and around LNP, 62 buffaloes were tested for bovine tuberculosis (BTB) and bovine brucellosis. The percentage of positive BTB reactors in buffalo was 8.06% using BovidTB Stat-Pak and 0% with BOVIGAM IFN-c test and IDEXX ELISA. The brucellosis seroprevalence in buffalo was found to be 17.72% and 27.42% using Rose Bengal Test (RBT) and ELISA, respectively. In addition, 2445 cattle in and around the LNP were examined for BTB using the single intradermal cervical comparative tuberculin test (SICCT), and an apparent prevalence of 0.98% was found with no significant difference inside (0.5%) and outside (1.3%) the park. This is the first published report on the presence of positive reactors to BTB and bovine brucellosis in buffalo and cattle in and outside the LNP. Monitoring the wildlife–livestock–human interface of zoonotic high-impact diseases such as BTB and brucellosis is of outmost importance for the successful implementation and management of any transfrontier park that aims to improve the livelihoods of the local communities.German Research Foundation (DFG).http://onlinelibrary.wiley.com/journal/10.1111/(ISSN)1865-16822016-12-31hb2016Veterinary Tropical Disease

    Accelerated surgery versus standard care in hip fracture (HIP ATTACK): an international, randomised, controlled trial

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    Molecular Current−Voltage Characteristics

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    Faster progression to AIDS and AIDS-related death among seroincident individuals infected with recombinant HIV-1 A3/CRF02_AG compared to sub subtype A3.

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    HIV-1 is divided into different subtypes and circulating recombinant forms (CRFs) but the impact of HIV-1 subtype/CRF on disease progression is not fully understood. We determined the HIV-1 subtype/CRF of 152 seroincident individuals from Guinea-Bissau, based on the C2-V3 region of env. Rate of disease progression was measured as time from estimated seroconversion to AIDS and AIDS-related death. Hazard ratios (HRs) were calculated using a Cox proportional hazard model, adjusting for gender and age at seroconversion. The major subtypes/CRFs identified were CRF02_AG (53%), A3 (29%) and A3/02 (a recombinant of A3 and CRF02_AG) (13%). Infection with A3/02 was associated with a close to 3-fold increased risk of AIDS and AIDS-related death compared to A3 (HR=2.6 [P=0.011] and 2.9 [P=0.032], respectively). The median estimated time from seroconversion to AIDS and AIDS-related death was 5.0 and 8.0 years for A3/02, 6.2 and 9.0 years for CRF02_AG and 7.2 and 11.3 years for A3. Our results show that there are significant differences in disease progression between HIV-1 A-like subtypes/CRFs. Individuals infected with the A3/02 recombinant have among the fastest progression rates to AIDS reported to date. Determining the HIV-1 subtype of infected individuals could be of importance in the management of HIV-1 infections
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