Fluctuation effects in the theory of microphase separation of diblock copolymers in the presence of an electric field

We generalize the Fredrickson-Helfand theory of the microphase separation in symmetric diblock copolymer melts by taking into account the influence of a time-independent homogeneous electric field on the composition fluctuations within the self-consistent Hartree approximation. We predict that electric fields suppress composition fluctuations, and consequently weaken the first-order transition. In the presence of an electric field the critical temperature of the order-disorder transition is shifted towards its mean-field value. The collective structure factor in the disordered phase becomes anisotropic in the presence of the electric field. Fluctuational modulations of the order parameter along the field direction are strongest suppressed. The latter is in accordance with the parallel orientation of the lamellae in the ordered state.Comment: 16 page

COVID-19 in pregnancy—characteristics and outcomes of pregnant women admitted to hospital because of SARS-CoV-2 infection in the Nordic countries

cited By 0Introduction Population-based studies about the consequences of SARS-CoV-2 infection (COVID-19) in pregnancy are few and have limited generalizability to the Nordic population and healthcare systems. Material and methods This study examines pregnant women with COVID-19 in the five Nordic countries. Pregnant women were included if they were admitted to hospital between 1 March and 30 June 2020 and had a positive SARS-CoV-2 PCR test Results In the study areas, 214 pregnant women with a positive test were admitted to hospital, of which 56 women required hospital care due to COVID-19. The risk of admission due to COVID-19 was 0.4/1000 deliveries in Denmark, Finland and Norway, and 3.8/1000 deliveries in the Swedish regions. Women hospitalized because of COVID-19 were more frequently obese (p < 0.001) and had a migrant background (p < 0.001) compared with the total population of women who delivered in 2018. Twelve women (21.4%) needed intensive care. Among the 56 women admitted due to COVID-19, 48 women delivered 51 infants. Preterm delivery (n = 12, 25%, p < 0.001) and cesarean delivery (n = 21, 43.8%, p < 0.001) were more frequent in women with COVID-19 compared with women who delivered in 2018. No maternal deaths, stillbirths or neonatal deaths were reported. Conclusions The risk of admission due to COVID-19 disease in pregnancy was low in the Nordic countries. A fifth of the women required intensive care and we observed higher rates of preterm and cesarean deliveries. National public health policies appear to have had an impact on the risk of admission due to severe COVID-19 disease in pregnancy. Nordic collaboration is important in collecting robust data and assessing rare outcomes.Peer reviewe

Determination of the Michel Parameters rho, xi, and delta in tau-Lepton Decays with tau --> rho nu Tags

Using the ARGUS detector at the $e^+ e^-$ storage ring DORIS II, we have measured the Michel parameters $\rho$, $\xi$, and $\xi\delta$ for $\tau^{\pm}\to l^{\pm} \nu\bar\nu$ decays in $\tau$-pair events produced at center of mass energies in the region of the $\Upsilon$ resonances. Using $\tau^\mp \to \rho^\mp \nu$ as spin analyzing tags, we find $\rho_{e}=0.68\pm 0.04 \pm 0.08$, $\xi_{e}= 1.12 \pm 0.20 \pm 0.09$, $\xi\delta_{e}= 0.57 \pm 0.14 \pm 0.07$, $\rho_{\mu}= 0.69 \pm 0.06 \pm 0.08$, $\xi_{\mu}= 1.25 \pm 0.27 \pm 0.14$ and $\xi\delta_{\mu}= 0.72 \pm 0.18 \pm 0.10$. In addition, we report the combined ARGUS results on $\rho$, $\xi$, and $\xi\delta$ using this work und previous measurements.Comment: 10 pages, well formatted postscript can be found at http://pktw06.phy.tu-dresden.de/iktp/pub/desy97-194.p

The preview study: Metabolic outcomes in overweight, prediabetic individuals after an 8-week low calorie diet

Abstracts / Journal of Nutrition & Intermediary Metabolism 8 (2017)Peer reviewe

Spectroscopy of geo-neutrinos from 2056 days of Borexino data

We report an improved geo-neutrino measurement with Borexino from 2056 days of data taking. The present exposure is $(5.5\pm0.3)\times10^{31}$ proton$\times$yr. Assuming a chondritic Th/U mass ratio of 3.9, we obtain $23.7 ^{+6.5}_{-5.7} (stat) ^{+0.9}_{-0.6} (sys)$ geo-neutrino events. The null observation of geo-neutrinos with Borexino alone has a probability of $3.6 \times 10^{-9}$ (5.9$\sigma$). A geo-neutrino signal from the mantle is obtained at 98\% C.L. The radiogenic heat production for U and Th from the present best-fit result is restricted to the range 23-36 TW, taking into account the uncertainty on the distribution of heat producing elements inside the Earth.Comment: 4 pages, 4 figure

Inclusive V0V^0 Production Cross Sections from 920 GeV Fixed Target Proton-Nucleus Collisions

Inclusive differential cross sections $d\sigma_{pA}/dx_F$ and $d\sigma_{pA}/dp_t^2$ for the production of \kzeros, \lambdazero, and \antilambda particles are measured at HERA in proton-induced reactions on C, Al, Ti, and W targets. The incident beam energy is 920 GeV, corresponding to $\sqrt {s} = 41.6$ GeV in the proton-nucleon system. The ratios of differential cross sections \rklpa and \rllpa are measured to be $6.2\pm 0.5$ and $0.66\pm 0.07$, respectively, for \xf $\approx-0.06$. No significant dependence upon the target material is observed. Within errors, the slopes of the transverse momentum distributions $d\sigma_{pA}/dp_t^2$ also show no significant dependence upon the target material. The dependence of the extrapolated total cross sections $\sigma_{pA}$ on the atomic mass $A$ of the target material is discussed, and the deduced cross sections per nucleon $\sigma_{pN}$ are compared with results obtained at other energies.Comment: 17 pages, 7 figures, 5 table

The Main Results of the Borexino Experiment

The main physical results on the registration of solar neutrinos and the search for rare processes obtained by the Borexino collaboration to date are presented.Comment: 8 pages, 8 figgures, To be published as Proceedings of the Third Annual Large Hadron Collider Physics Conference, St. Petersburg, Russia, 201

Measurement of neutrino flux from the primary proton--proton fusion process in the Sun with Borexino detector

Neutrino produced in a chain of nuclear reactions in the Sun starting from the fusion of two protons, for the first time has been detected in a real-time detector in spectrometric mode. The unique properties of the Borexino detector provided an oppurtunity to disentangle pp-neutrino spectrum from the background components. A comparison of the total neutrino flux from the Sun with Solar luminosity in photons provides a test of the stability of the Sun on the 10$^{5}$ years time scale, and sets a strong limit on the power production in the unknown energy sources in the Sun of no more than 4\% of the total energy production at 90\% C.L.Comment: 15 pages, 2 tables, 3 figure