Fourteen-day survival among older adults with severe infection with severe acute respiratory syndrome coronavirus 2 treated with corticosteroid: a cohort study

Objective

To assess the effectiveness of corticosteroids among older adults with coronavirus disease 2019 (COVID-19) pneumonia requiring oxygen.

Methods

We used routine care data from 36 hospitals in France and Luxembourg to assess the effectiveness of corticosteroids with at least 0.4 mg/kg/day equivalent prednisone (treatment group) versus standard of care (control group). Participants were adults aged 80 years or older with PCR-confirmed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection or CT scan images typical of COVID-19 pneumonia, requiring oxygen ≥3 L/min, and with an inflammatory syndrome (C-reactive protein ≥40 mg/L). The primary outcome was overall survival at day 14. In our main analysis, characteristics of patients at baseline (i.e. time when patients met all inclusion criteria) were balanced by using propensity-score inverse probability of treatment weighting.

Results

Among the 267 patients included in the analysis, 98 were assigned to the treatment group. Their median age was 86 years (interquartile range 83–90 years) and 95% had a SARS-CoV-2 PCR-confirmed diagnosis. In total, 43/98 (43.9%) patients in the treatment group and 84/166 (50.6%) in the control group died before day 14 (weighted hazard ratio 0.67, 95% CI 0.46–0.99). The treatment and control groups did not differ significantly for the proportion of patients discharged to home/rehabilitation at day 14 (weighted relative risk 1.12, 95% CI 0.68–1.82). Twenty-two (16.7%) patients receiving corticosteroids developed adverse events, but only 11 (6.4%) from the control group.

Conclusions

Corticosteroids were associated with a significant increase in the overall survival at day 14 of patients aged 80 years and older hospitalized for severe COVID-19.

Unexpectedly Large Electron Correlation Measured in Auger Spectra of Ferromagnetic Iron Thin Films: Orbital-Selected Coulomb and Exchange Contributions

A set of electron-correlation energies as large as 10 eV have been measured for a magnetic 2 ML Fe film deposited on Ag(001). By exploiting the spin selectivity in angle-resolved Auger-photoelectron coincidence spectroscopy and the Cini-Sawatzky theory, the core-valence-valence Auger spectrum of a spin-polarized system have been resolved: correlation energies have been determined for each individual combination of the two holes created in the four subbands involved in the decay: majority and minority spin, as well as e_{g} and t_{2g}. The energy difference between final states with parallel and antiparallel spin of the two emitted electrons is ascribed to the spin-flip energy for the final ion state, thus disentangling the contributions of Coulomb and exchange interactions.

Rippling of graphitic surfaces: a comparison between few-layer graphene and HOPG

The surface structure of Few-Layer Graphene (FLG) epitaxially grown on the C-face of SiC has been investigated by TM-AFM in ambient air and upon interaction with dilute aqueous solutions of bio-organic molecules (l-methionine and dimethyl sulfoxide, DMSO). Before interaction with molecular solutions, we observe nicely ordered, three-fold oriented rippled domains, with a 4.7 ± 0.2 nm periodicity (small periodicity, SP) and a peak-to-valley distance in the range 0.1-0.2 nm. Upon mild interaction with the molecular solution, the ripple periodicity "relaxes" to 6.2 ± 0.2 nm (large periodicity, LP), while the peak-to-valley height increases to 0.2-0.3 nm. When additional energy is transferred to the system through sonication in solution, graphene planes are peeled off, as shown by quantitative analysis of Raman spectroscopy and X-ray photoelectron spectroscopy which indicate a neat reduction of thickness. Upon exfoliation rippled domains are no longer observed. In comparative experiments on cleaved HOPG, we could not observe ripples on pristine samples in ambient air, while LP ripples develop upon interaction with the molecular solutions. Recent literature on similar systems is not univocal regarding the interpretation of rippling. The ensemble of our comparative observations on FLG and HOPG can be hardly rationalized solely on the basis of the surface assembly of molecules, either organic molecules coming from the solution or adventitious species. We propose to consider rippling as the manifestation of the free-energy minimization of quasi-2D layers, eventually affected by factors such as interplanar stacking, and interactions with molecules and/or with the AFM tip.

Prevalence of HIV-1 Subtypes and Drug Resistance-Associated Mutations in HIV-1-Positive Treatment-Naive Pregnant Women in Pointe Noire, Republic of the Congo (Kento-Mwana Project)

The Kento-Mwana project was carried out in Pointe Noire, Republic of the Congo, to prevent mother-to-child HIV-1 transmission. To determine the prevalence of different subtypes and transmitted drug resistance-associated mutations, 95 plasma samples were collected at baseline from HIV-1-positive naive pregnant women enrolled in the project during the years 2005-2008. Full protease and partial reverse transcriptase sequencing was performed and 68/95 (71.6%) samples were successfully sequenced. Major mutations to nucleoside reverse transcriptase inhibitors, nonnucleoside reverse transcriptase inhibitors, and protease inhibitors were detected in 4/68 (5.9%), 3/68 (4.4%), and 2/68 (2.9%) samples, respectively. Phylogenetic analysis of HIV-1 isolates showed a high prevalence of unique recombinant forms (24/68, 35%), followed by CRF45_cpx (7/68, 10.3%) and subsubtype A3 and subtype G (6/68 each, 8.8%). Although the prevalence of transmitted drug resistance mutations appears to be currently limited, baseline HIV-1 genotyping is highly advisable in conjunction with antiretroviral therapy scale-up in resource-limited settings to optimize treatment and prevent perinatal transmission.

Pregnancy outcomes following exposure to efavirenz-based antiretroviral therapy in the Republic of Congo

WHO recently recommended efavirenz (EFV) use for HIV infection through pregnancy, breastfeeding and childbearing age. However the use of EFV during pregnancy remains of concern and not all national guidelines reflect WHO advice. Few data are available concerning pregnancy outcomes. The objective of our study was to evaluate pregnancy outcomes in a cohort of women who conceived on EFV. A retrospective, multicenter cohort study was conducted in Pointe Noire, Republic of Congo (September 2005- June 2012). The following adverse pregnancy outcomes were considered: births defects, low birth weight, premature delivery, stillbirth and abortion, stratified by antiretroviral exposure at the time of conception. During the study period, 188 women conceived on antiretrovirals: 35 (18.6%) on EFV-based regimens and 153 (81.4%) on nevirapine-based regimens. Adverse pregnancy outcomes were observed in 17/35 (48.6%, 95% CI 33.0-64.4%) women in the EFV group and in 43/153 (28.1%, 95% CI 21.6-35.7%) in the non-EFV group (p=0.019). No birth defect was observed in either group. An increased incidence of adverse pregnancy outcomes was observed in the EFV group. As WHO is promoting a widespread use of EFV also for women in childbearing age, our study emphasizes the importance of launching large prospective cohort studies investigating pregnancy outcomes in exposed women.

Oscillations of the orbital magnetic moment due to d-band quantum well states

The effect of electron confinement on the magnetocrystalline anisotropy of ultrathin bcc Fe films is explored by combining photoemission spectroscopy, x-ray magnetic circular dichroism, and magneto-optical Kerr effect measurements. Pronounced thickness-dependent variations in the magnetocrystalline anisotropy are ascribed to periodic changes in the density of states at the Fermi level, induced by quantization of d(xz), d(yz) out-of-plane orbitals. Our results reveal a direct correlation between quantum well states, the orbital magnetic moment, and the magnetocrystalline anisotropy.

Reentrant surface anisotropy in the antiferromagnetic/ferromagnetic bilayer Mn/Co/Cu(001)

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 (tMn) between 1 and 2 monolayers, which disappears for Mn thickness above 2 monolayers. In the Mn/Co/Cu(001) system, Mn films undergo a tMn-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, is therefore proposed as the origin of the reentrant anisotropy.

Effectiveness of a project to prevent HIV vertical transmission in the Republic of Congo

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.

Successfully treated HIV-infected patients have differential expression of NK cell receptors (NKp46 and NKp30) according to AIDS status at presentation

Differences in innate immune responses may be associated with different capabilities of controlling HIV infection, not necessarily reflected by CD4(+) T-cell counts alone. We investigated by cytofluorometry the expression of NK cell receptors and ligands in 19 treated HIV-infected patients with CD4(+)<220 ml(-1) at presentation (11 AIDS, 8 non-AIDS) and 10 healthy donors. Expression of NKp46 and NKp30 was significantly higher in non-AIDS vs. AIDS patients. Overall, the level of NKp46 expression directly correlated with the degree of NK cell cytotoxicity. As compared to healthy donors, in both groups, there was a similar increase of CD69 and HLA-DR expression in NK cells that directly correlated with the presence of activation markers (HLA-DR) on CD4(+) and CD8(+) T cells. As compared to AIDS, in non-AIDS patients in vitro activated CD4(+) showed higher expression of MIC-A (NKG2D ligand), with significantly higher Nectin-2/DNAM-1 and MIC-A/NKG2D ratios. Thus, NK cell responses in AIDS and non-AIDS patients with similar CD4(+) counts significantly differ despite similar treatment. This suggests an involvement of innate mechanisms, in preventing AIDS-defining opportunistic infections in HIV infection and further suggests, that CD4(+) absolute counts alone, may be inadequate to explain differences in the clinical outcome.

Tuning the magneto-optical response of iron oxide nanocrystals in Au- and Ag-based plasmonic media

We investigated the magneto-optical response of chemically synthesized iron oxide magnetic nanocrystals, optically coupled with ordered planar arrays of plasmonic nanoparticles. We compare the signals from two classes of systems, featuring either Au or Ag as the plasmonic counterpart. The localized surface plasmon resonance of the Ag and Au nanoparticles arrays were superimposed or detuned, respectively, with respect to the dominant magneto-optical transitions of the magnetic material. Under resonance, a significant enhancement of the magneto-optical signal was observed. In both cases, we could separate the purely plasmonic and the magnetic contributions in the magneto-optical spectrum of the optically coupled composite based on their different magnetic-field dependence.

Band structure effects in above threshold photoemission

We have performed an angle-resolved two-photon and three-photon photoemission study of the Ag(111) surface employing ultrashort laser pulses as the excitation source. We show the presence of multi-photon resonances between electronic states at selected points of the Brillouin zone which appear in the high-order photoemission spectral region. We observe clear signatures of electronic band structure effects of the Ag crystal in above-threshold photoemission (ATP) processes, identifying two types of transitions, which either proceed via non-resonant multi-photon excitation from an occupied initial state, or involve a real intermediate state located above the vacuum level of the solid directly influencing the ATP process. For this latter class of phenomena, we suggest that electron populations created by incoherent processes give a contribution to the multi-photon transition, possibly allowing us to trace the transmission of photoexcited electrons through the crystal.

Interaction of alkanethiols with nanoporous cluster-assembled Au films

This article presents a study of the interaction of octadecanethiol molecules (C(18)) with nanoporous cluster-assembled gold films under a liquid environment based on a combined spectroscopic ellipsometry and X-ray photoelectron spectroscopy investigation. By comparing the optical response, following the deposition of C(18), of cluster-assembled films with varying degrees of porosity with that of flat surfaces and by resolving the corresponding features of the molecule-Au bond, we have been able to define the conditions that either favor molecular in-depth diffusion into the pores or promote the formation of a molecular self-assembled monolayer (SAM) restricted to the film surface. In the presence of abundant open pores, C(18) molecules strongly diffuse within the film interior and bind to the pore walls, whereas in the presence of porous films with less abundant open pores we have observed that the molecules tend to remain confined to the surface region, adopting a SAM-like configuration.

Growth dynamics of L-cysteine SAMs on single-crystal gold surfaces: a metastable deexcitation spectroscopy study

We report on a metastable deexcitation spectroscopy investigation of the growth of L-cysteine layers deposited under UHV conditions on well-defined Au(110)- (1 × 2) and Au(111) surfaces. The interaction of He(*) with molecular orbitals gave rise to well-defined UPS-like Penning spectra which provided information on the SAM assembly dynamics and adsorption configurations. Penning spectra have been interpreted through comparison with molecular orbital DFT calculations of the free molecule and have been compared with XPS results of previous works. Regarding adsorption of first-layer molecules at room temperature (RT), two different growth regimes were observed. On Au(110), the absence of spectral features related to orbitals associated with SH groups indicated the formation of a compact SAM of thiolate molecules. On Au(111), the data demonstrated the simultaneous presence, since the early stages of growth, of strongly and weakly bound molecules, the latter showing intact SH groups. The different growth mode was tentatively assigned to the added rows of the reconstructed Au(110) surface which behave as extended defects effectively promoting the formation of the S-Au bond. The growth of the second molecular layer was instead observed to proceed similarly for both substrates. Second-layer molecules preferably adopt an adsorption configuration in which the SH group protrudes into the vacuum side.

HIV serological screening in a population of pregnant women in the Republic of Congo: suitability of different assays

Different strategies can be applied for the screening of HIV infection, depending on the local seroprevalence. Within a WHO type III strategy, we compared the results of two different second-line methods for HIV screening of a population of pregnant women in the Republic of Congo. Sera from 3614 consecutive pregnant women were tested for HIV with Genescreen Plus Ag/Ab EIA assay; positive specimens were retested with two different second-line methods. (Determine HIV-1/2 rapid test and Vironostika HIV Ag/Ab specific EIA assay). Discordant samples were tested with HIV-1/2 Western Blot and, if necessary, HIV RNA molecular assay. Of the 3614 sera, 221 were positive with Genscreen. Among them, 21 and 10 tested negative with Vironostika and Determine, respectively. A 100% correspondence with 3rd line confirmation test results was found in Genscreen positive/Vironostika negative samples, whereas a 5.5% overestimation of HIV seroprevalence was observed when Determine, instead of Vironostika, was used as second-line test. The choice of appropriate assays in adequate sequence, within the correct WHO strategy, is pivotal to minimize the risk of overtreatment of HIV infection.

Ultrafast optical spin injection into image-potential states of Cu(001)

We report the observation of a net spin polarization in the n=1 image-potential state at the Cu(001) surface. The spin polarization is achieved by spin-selective multiphoton excitation of electrons from the spin-orbit split Cu d bands to the image-potential state using circularly polarized ultrafast light pulses. We show that by tuning the exciting photon energy, we can adjust the resonant coupling of the image-potential state to d bands of different double-group symmetry. This allows us to tune the spin polarization injected into the image-potential state.

Incidence, risk factors, and predictors of outcome of candidemia. Survey in 2 Italian university hospitals

In recent decades, Candida spp. emerged as the fourth most common cause of nosocomial bloodstream infections. The incidence of candidemia was 0.13 per 100 persons. Eighty-three cases (61%) of candidemia were due to Candida albicans and 53 (39%) to nonalbicans Candida spp. Twelve strains of Candida (9%) had shown in vitro resistance to fluconazole, 5 (4%) to itraconazole, 2 (1.5%) to voriconazole, 12 (9%) to 5-flucytosine, and 1 (0.7%) to amphotericin B. Multivariate logistic regression analysis of risk factors showed that length of hospitalization, presence of a central venous catheter, previous episodes of candidemia or bacteremia, parenteral nutrition, and chronic renal failure were variables independently associated with the development of candidemia. Multivariate logistic regression analysis of prognostic indicators showed that the independent variables associated with poor prognosis were inadequate initial therapy (P < .001) and high APACHE III score (P = .004). The inadequate initial therapy associated with mortality indicates the need for additional investigations to define high-risk patients for beneficial antifungal prophylaxis.

Mechanisms of high-order perturbative photoemission from Cu(001)

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.

Isolating the step contribution to the uniaxial magnetic anisotropy in nanostructured Fe/Ag(001) films

We have investigated the possibility of isolating the step-induced in-plane uniaxial magnetic anisotropy in Fe/Ag(001) films on which nanoscale surface ripples were fabricated by the ion sculpting technique. For rippled Fe films deposited on flat Ag(001), the steps created along the ripple sidewalls are shown to be the only source of uniaxial anisotropy. Ion sculpting of ultrathin magnetic films allows one to selectively study the step-induced anisotropy and to investigate the correlation between local atomic environment and magnetic properties.

Surface magnetism during oxygen-aided Fe homoepitaxy

Magnetization-induced optical surface second harmonic generation (SHG) in the longitudinal geometry was used to study magnetism on the p(1 x 1)O/Fe(001) surface during a layer-by-layer Fe growth with surfactant oxygen. Considerable one-monolayer oscillations were observed. Minima of the magnetization-induced contributions to the second order dielectric susceptibility were detected at half-filled monolayers. These contributions were accessed either by measuring a purely magnetic SHG yield, or indirectly from the magnetization dependence of the overall SHG signal, both providing consistent results. The origin of the oscillatory surface magnetism is consistent with the expected oscillating oxygen induced relaxation due to the surface Fe islands.

Temperature driven reversible breakdown of pseudomorphism in ultrathin Fe/Cu3Au films

We observe that ultrathin Fe/Cu(3)Au(001) films in the 6-13 A thickness range, beyond the thickness of pseudomorphism breakdown at room temperature, exhibit a temperature dependent structural phase transition in the range T(c) approximately 345-380 K. In the high temperature state the Fe film becomes pseudomorphic, while breakdown of pseudomorphism reversibly occurs as the system is cooled below the transition temperature. The difference between substrate and overlayer thermal expansion coefficient is highlighted as the driving force for the observed transition.