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Purpose: To compare the macular assessment and retinal nerve fiber layer (RNFL) thickness by using two different optical coherence tomographies (OCTs): a time domain (TD) and a spectral domain (SD) OCT, in multiple sclerosis (MS) patients with and without unilateral optic neuritis (ON). Methods: We enrolled 34 patients (13 males and 21 females): 18 without previous episodes of ON and16 with a previous monolateral episode of ON occurred at least 3 months prior to examination. Patients underwent ophthalmological examination, TD OCT and SD OCT scans. We compared the outcomes of eyes with and without ON by using Student’s t test. Results: In the affected eye group a reduction of the average RNFL was found using TD OCT (reduction of 22.8%) with the difference between the two groups being statistically significant (p

OBJECTIVES: To evaluate the effectiveness of a prevention programme against the vertical transmission of HIV in a resource-limited setting and to investigate variables associated with compliance. PATIENTS AND METHODS: The Kento-Mwana project (2005-2008) provided counselling, serological and biomolecular testing and prophylaxis/therapy to HIV-positive pregnant women and their children attending four antenatal clinics in Pointe Noire, Republic of Congo. Expected and actual rates of vertical transmission of HIV were compared. Univariate and multivariate analyses were performed in order to identify variables associated with non-compliance. RESULTS: The observed transmission rate in the group who completed follow-up was 5/290 (1.7%, 95% CI 0.6%-4.1%). The overall estimated transmission rate in the target population, computed taking into account the expected vertical transmission of HIV among drop-outs, was 67-115/638 (10.5%-18.0%). A comparison between this rate and the expected transmission rate in the absence of intervention (25%-40%) showed that the programme was able to prevent approximately 50% of vertical transmissions. Older age (OR 0.33, 95% CI 0.16-0.66, P = 0.002), telephone availability (OR 0.42, 95% CI 0.24-0.72, P = 0.002) and occupation (OR 0.57, 95% CI 0.29-1.10, P = 0.092) were associated with better compliance. CONCLUSIONS: Despite the vast majority of women accepting counselling and testing, many of them refused prophylaxis or dropped out, thus reducing the effectiveness of the intervention from an ideal 2% to a still important but less impressive median transmission rate of 15% (range 10.5%-18%). Promoting participation and compliance, rather than increasing the potency of antiretroviral regimens, is crucial for preventing the vertical transmission of HIV in Africa

We investigated the magnetic anisotropy energy of monatomic surface-step atoms in antiferromagnetic/ferromagnetic (AF/FM) epitaxial Mn/Co bilayers grown on vicinal Cu(001) surfaces. The step-induced anisotropy of the Co/Cu(001) films was quenched upon submonolayer Mn deposition, but a reentrant uniaxial surface anisotropy was observed for Mn thickness (t(Mn)) between 1 and 2 monolayers, which disappears for Mn thickness above 2 monolayers. In the Mn/Co/Cu(001) system, Mn films undergo a t(Mn)-dependent transition from FM to AF in the 1-2 Mn monolayer thickness range, which entails the coexistence of FM and AF Mn phases in the film. The observation of a sizeable uniaxial anisotropy exclusively in the Mn-thickness range of coexistence of the FM and AF phases points out the crucial role of the boundaries between FM and AF regions within the Mn film. A symmetry-breaking mechanism of a magnetic type, rather than a purely geometric one, anisotropy.

Background: Factors influencing the outcome of structured treatment interruptions (STIs) in HIV chronic infection are not fully elucidated. Methods: In ISS-PART, 273 subjects were randomly assigned to arm A (137 assigned to continuous highly active antiretroviral therapy [HAART]) and arm B (136 assigned to 5 STIs of 1, 1, 2, 2, and 3 months'duration, each followed by 3 months of therapy). Main outcome measures were the proportion of subjects with a CD4 count >500 cells/mm 3 , the rate of virologic failure, and the emergence of resistance at 24 months. Results: The proportion of subjects with a CD4 count >500 cells/mm 3 was higher in arm A than in arm B (86.5% vs. 69.1%; P = 0.0075). Pre-HAART CD4 cell count and male gender were independent predictors of a CD4 count >500 cells/mm 3 in arm B. The overall risk of virologic failure was not increased in arm B; however, it was higher in the 38 subjects who had resistance mutations in the rebounding virus. Archived mutations at baseline and the use of a regimen that included an unboosted protease inhibitor (PI), compared with nonnucleoside reverse transcriptase inhibitor-based HAART, independently predicted the emergence of plasma mutations during STI (P = 0.002 for DNA mutations and P = 0.048 for PI-based HAART). Conclusions: Our results suggest that patients with preexisting mutations and treated with unboosted PI-based HAART should not be enrolled in studies of time-fixed treatment interruptions, being at higher risk of developing plasma mutations during STI and virologic failure at therapy reinstitution.

We observed high-order 2- to 4-photon photoemission and above threshold photoemission (ATP) processes with 3.07 eV light from the Cu(001) surface. The intensity of 3-photon photoemission via excitation through the n=1 image potential state significantly exceeded that of the 2-photon process. The ATP occurs either via single photon transitions from the image potential resonances above the vacuum level or by multiphoton transitions from image potential states below the vacuum level. The experimental ratio of the m- to (m+1)-photon process yields is sensitive to the electronic band structure of the solid.

Structural and electronic properties of ultrathin Mg films on Ag(1 0 0) have been investigated by means of metastable de-excitation spectroscopy (MDS), work function change (”), electron diffraction and helium reflectivity (RHe) measurements. At room temperature Mg grows on Ag(1 0 0) following the Stranski–Krastanov growth mode. Successive annealing of a 10 ML thick Mg film leads to its almost complete desorption at about 390 K and to the formation of a Mg–Ag alloy. RHe and electron diffraction measurements indicate that for annealing temperatures between 480 and 570 K, the alloy orders with a c(2×2) periodicity. Further annealing at higher temperatures restores the initial Ag(1 0 0) surface.

Temperature dependence of the magnetic properties of ultrathin Fe/Cu3Au films (thickness