Feynman integral relations from parametric annihilators

We study shift relations between Feynman integrals via the Mellin transform through parametric annihilation operators. These contain the momentum space IBP relations, which are well-known in the physics literature. Applying a result of Loeser and Sabbah, we conclude that the number of master integrals is computed by the Euler characteristic of the Lee-Pomeransky polynomial. We illustrate techniques to compute this Euler characteristic in various examples and compare it with numbers of master integrals obtained in previous works.Comment: v2: new section 3.1 added, several misprints corrected and additional remark

Estimating Trends in the Proportion of Transmitted and Acquired HIV Drug Resistance in a Long Term Observational Cohort in Germany

Objective: We assessed trends in the proportion of transmitted (TDR) and acquired (ADR) HIV drug resistance and associated mutations between 2001 and 2011 in the German ClinSurv-HIV Drug Resistance Study. Method: The German ClinSurv-HIV Drug Resistance Study is a subset of the German ClinSurv-HIV Cohort. For the ClinSurv-HIV Drug Resistance Study all available sequences isolated from patients in five study centres of the long term observational ClinSurv-HIV Cohort were included. TDR was estimated using the first viral sequence of antiretroviral treatment (ART) naive patients. One HIV sequence/patient/year of ART experienced patients was considered to estimate the proportion of ADR. Trends in the proportion of HIV drug resistance were calculated by logistic regression. Results: 9,528 patients were included into the analysis. HIV-sequences of antiretroviral naive and treatment experienced patients were available from 34% (3,267/9,528) of patients. The proportion of TDR over time was stable at 10.4% (95% CI 9.1-11.8; p (for trend)=0.6; 2001-2011). The proportion of ADR among all treated patients was 16%, whereas it was high among those with available HIV genotypic resistance test (64%; 1,310/2,049 sequences; 95% CI 62-66) but declined significantly over time (OR 0.8; 95% CI 0.77-0.83; p (for trend)<0.001; 2001-2011). Viral load monitoring subsequent to resistance testing was performed in the majority of treated patients (96%) and most of them (67%) were treated successfully. Conclusions: The proportion of TDR was stable in this study population. ADR declined significantly over time. This decline might have been influenced by broader resistance testing, resistance test guided therapy and the availability of more therapeutic options and not by a decline in the proportion of TDR within the study population

ECCENTRIC: a fast and unrestrained approach for high-resolution in vivo metabolic imaging at ultra-high field MR

A novel method for fast and high-resolution metabolic imaging, called ECcentric Circle ENcoding TRajectorIes for Compressed sensing (ECCENTRIC), has been developed and implemented on 7 Tesla human MRI. ECCENTRIC is a non-Cartesian spatial-spectral encoding method optimized for random undersampling of magnetic resonance spectroscopic imaging (MRSI) at ultra-high field. The approach provides flexible and random (k,t) sampling without temporal interleaving to improve spatial response function and spectral quality. ECCENTRIC needs low gradient amplitudes and slew-rates that reduces electrical, mechanical and thermal stress of the scanner hardware, and is robust to timing imperfection and eddy-current delays. Combined with a model-based low-rank reconstruction, this approach enables simultaneous imaging of up to 14 metabolites over the whole-brain at 2-3mm isotropic resolution in 4-10 minutes with high signal-to-noise ratio. In 20 healthy volunteers and 20 glioma patients ECCENTRIC demonstrated unprecedented mapping of fine structural details of metabolism in healthy brains and an extended metabolic fingerprinting of glioma tumors.Comment: 20 pages, 7 figures,2 tables, 10 pages supplementary materia

an evaluation of data sources to determine the number of people living with HIV who are receiving antiretroviral therapy in Germany

Background This study aimed to determine the number of people living with HIV receiving antiretroviral therapy (ART) between 2006 and 2013 in Germany by using the available numbers of antiretroviral drug prescriptions and treatment data from the ClinSurv HIV cohort (CSH). Methods The CSH is a multi-centre, open, long-term observational cohort study with an average number of 10.400 patients in the study period 2006–2013. ART has been documented on average for 86% of those CSH patients and medication history is well documented in the CSH. The antiretroviral prescription data (APD) are reported by billing centres for pharmacies covering >99% of nationwide pharmacy sales of all individuals with statutory health insurance (SHI) in Germany (~85%). Exactly one thiacytidine-containing medication (TCM) with either emtricitabine or lamivudine is present in all antiretroviral fixed-dose combinations (FDCs). Thus, each daily dose of TCM documented in the APD is presumed to be representative of one person per day receiving ART. The proportion of non-TCM regimen days in the CSH was used to determine the corresponding number of individuals in the APD. Results The proportion of CSH patients receiving TCMs increased continuously over time (from 85% to 93%; 2006–2013). In contrast, treatment interruptions declined remarkably (from 11% to 2%; 2006–2013). The total number of HIV-infected people with ART experience in Germany increased from 31,500 (95% CI 31,000-32,000) individuals to 54,000 (95% CI 53,000-55,500) over the observation period (including 16.3% without SHI and persons who had interrupted ART). An average increase of approximately 2,900 persons receiving ART was observed annually in Germany. Conclusions A substantial increase in the number of people receiving ART was observed from 2006 to 2013 in Germany. Currently, the majority (93%) of antiretroviral regimens in the CSH included TCMs with ongoing use of FDCs. Based on these results, the future number of people receiving ART could be estimated by exclusively using TCM prescriptions, assuming that treatment guidelines will not change with respect to TCM use in ART regimens

Bioavailability of extended-release nevirapine 400 and 300 mg in HIV-1 : a multicenter, open-label study

Nevirapine (NVP) is a widely used non-nucleoside reverse transcriptase inhibitor. A once-daily extended-release (XR) formulation would potentially increase adherence and thus efficacy