Temporal characterization of individual harmonics of an attosecond pulse train by THz streaking

We report on the global temporal pulse characteristics of individual harmonics in an attosecond pulse train by means of photo-electron streaking in a strong low-frequency transient. The scheme allows direct retrieval of pulse durations and first order chirp of individual harmonics without the need of temporal scanning. The measurements were performed using an intense THz field generated by tilted phase front technique in LiNbO_3 . Pulse properties for harmonics of order 23, 25 and 27 show that the individual pulse durations and linear chirp are decreasing by the harmonic order

Reverse Foam Sclerotherapy of the Great Saphenous Vein with Sapheno-Femoral Ligation Compared to Standard and Invagination Stripping: a Prospective Clinical Series

AbstractObjectivesComparison of Reverse Foam Sclerotherapy of the great saphenous vein (GSV) combed with sapheno-femoral junction (SFJ) ligation to standard (Babcock) stripping and invagination (Pin) stripping in a prospective clinical series.DesignProspective clinical series.Materials and methods90 consecutive limbs of 82 patients with incompetence of the GSV resulting in varicose veins were prospectively randomised into 3 groups of 30, treated by SFJ ligation and either reverse foam sclerotherapy, standard stripping or invagination stripping of the GSV. Outcomes were assessed post-operatively and at 2-weeks follow-up. Peri-operative blood loss (24 hrs), analgesic requirement, bruising and residual varicosities were assessed. Bruising was assessed by both patients and independent assessors using questionnaires.ResultsSFJ ligation plus reverse foam sclerotherapy of the GSV was associated with significantly less blood loss, bruising and post-op discomfort than either of the stripping techniques. (p<0.001, Mann-Whitney)ConclusionStandard stripping of the GSV and invagination stripping are not associated with major discomfort and problems in the early post-operative period. SFJ ligation and GSV reverse foam sclerotherapy yielded greater patient satisfaction with less post-op bruising and discomfort and reduced analgesic requirements

Increased Sensitivity to Possible Muonium to Antimuonium Conversion

A new experimental search for muonium-antimuonium conversion was conducted at the Paul Scherrer Institute, Villigen, Switzerland. The preliminary analysis yielded one event fulfilling all required criteria at an expected background of 1.7(2) events due to accidental coincidences. An upper limit for the conversion probability in 0.1 T magnetic field is extracted as $8 \cdot 10^{-11}$ (90% CL).Comment: 2 figure

Does menopause transition influence viral suppression and adherence in Women living with HIV?

BACKGROUND Increasing numbers of women living with HIV transition through menopause. It is unclear if this transition has an impact on treatment adherence, viral suppression, psychiatric comorbidities or drug use. We aimed at examining adherence and viral suppression during the perimenopausal period and explored the influence of psychiatric comorbidities and active injection drug use (IDU). SETTING Retrospective Swiss HIV Cohort Study analysis from 01/2010 to 12/2018. METHODS We explored peri- and postmenopausal trends of viral blips, low-level viremia, viral failure, adherence, psychiatric comorbidities and IDU using interrupted time series (ITS) models. RESULTS Rates of depression and psychiatric care increased during perimenopause before decreasing afterwards. Negative treatment outcomes such as viral blips, low-level viremia, viral failure and low adherence steadily declined while transitioning through menopause - this was also true for subgroups of women with depression, psychiatric treatment and active IDU. CONCLUSIONS Increased rates of depression and psychiatric care while transitioning through menopause do not result in lower rates of adherence or viral suppression in women living with HIV in Switzerland

Hepatitis C virus cell-cell transmission and resistance to direct-acting antiviral agents

Hepatitis C virus (HCV) is transmitted between hepatocytes via classical cell entry but also uses direct cell-cell transfer to infect neighboring hepatocytes. Viral cell-cell transmission has been shown to play an important role in viral persistence allowing evasion from neutralizing antibodies. In contrast, the role of HCV cell-cell transmission for antiviral resistance is unknown. Aiming to address this question we investigated the phenotype of HCV strains exhibiting resistance to direct-acting antivirals (DAAs) in state-of-the-art model systems for cell-cell transmission and spread. Using HCV genotype 2 as a model virus, we show that cell-cell transmission is the main route of viral spread of DAA-resistant HCV. Cell-cell transmission of DAA-resistant viruses results in viral persistence and thus hampers viral eradication. We also show that blocking cell-cell transmission using host-targeting entry inhibitors (HTEIs) was highly effective in inhibiting viral dissemination of resistant genotype 2 viruses. Combining HTEIs with DAAs prevented antiviral resistance and led to rapid elimination of the virus in cell culture model. In conclusion, our work provides evidence that cell-cell transmission plays an important role in dissemination and maintenance of resistant variants in cell culture models. Blocking virus cell-cell transmission prevents emergence of drug resistance in persistent viral infection including resistance to HCV DAAs

Towards a high precision calculation for the pion-nucleus scattering lengths

We calculate the leading isospin conserving few-nucleon contributions to pion scattering on $^2$H, $^3$He, and $^4$He. We demonstrate that the strong contributions to the pion-nucleus scattering lengths can be controlled theoretically to an accuracy of a few percent for isoscalar nuclei and of 10% for isovector nuclei. In particular, we find the $\pi$-$^3$He scattering length to be $(62 \pm 4\pm 7)\times 10^{-3} m_{\pi}^{-1}$ where the uncertainties are due to ambiguities in the $\pi$-N scattering lengths and few-nucleon effects, respectively. To establish this accuracy we need to identify a suitable power counting for pion-nucleus scattering. For this purpose we study the dependence of the two-nucleon contributions to the scattering length on the binding energy of $^2$H. Furthermore, we investigate the relative size of the leading two-, three-, and four-nucleon contributions. For the numerical evaluation of the pertinent integrals, aMonte Carlo method suitable for momentum space is devised. Our results show that in general the power counting suggested by Weinberg is capable to properly predict the relative importance of $N$-nucleon operators, however, it fails to capture the relative strength of $N$- and $(N+1)$-nucleon operators, where we find a suppression by a factor of 5 compared to the predicted factor of 50. The relevance for the extraction of the isoscalar $\pi$-N scattering length from pionic $^2$H and $^4$He is discussed. As a side result, we show that beyond the calculation of the $\pi$-$^2$H scattering length is already beyond the range of applicability of heavy pion effective field theory.Comment: 24 pages, 14 figures, 10 table

Planck scale effects in neutrino physics

We study the phenomenology and cosmology of the Majoron (flavon) models of three active and one inert neutrino paying special attention to the possible (almost) conserved generalization of the Zeldovich-Konopinski-Mahmoud lepton charge. Using Planck scale physics effects which provide the breaking of the lepton charge, we show how in this picture one can incorporate the solutions to some of the central issues in neutrino physics such as the solar and atmospheric neutrino puzzles, dark matter and a 17 keV neutrino. These gravitational effects induce tiny Majorana mass terms for neutrinos and considerable masses for flavons. The cosmological demand for the sufficiently fast decay of flavons implies a lower limit on the electron neutrino mass in the range of 0.1-1 eV.Comment: 24 pages, 1 figure (not included but available upon request), LaTex, IC/92/196, SISSA-140/92/EP, LMU-09/9