False alarms during recognition of famous people from faces and voices in patients with unilateral temporal lobe resection and normal participants tested after anodal tDCS over the left or right ATL.

Data gathered in the field of the experimental social psychology have shown that it is more difficult to recognize a person through his/her voice than through his/her face and that false alarms (FA) are produced more in voice than in face recognition. Furthermore, some neuropsychological investigations have suggested that in patients with damage to the right anterior temporal lobe (ATL) the number of FA could be higher for voice than for face recognition. In the present study we assessed FA during recognition of famous people from faces and voices in patients with unilateral ATL tumours and in normal participants tested after anodal transcranial direct current stimulation (tCDS), over the left or right ATL. The number of FA was significantly higher in patients with right than in those with left temporal tumours on both face and voice familiarity. Furthermore, lesion side did not differentially affect patient's sensitivity or response criterion when recognizing famous faces, but influenced both these measures on a voice recognition task. In fact, in this condition patients with right temporal tumours showed a lower sensitivity index and a lower response criterion than those with left-sided lesions. In normal subjects, the greater right sided involvement in voice than in face processing was confirmed by the observation that right ATL anodal stimulation significantly increased voice but only marginally influenced face sensitivity. This asymmetry between face and voice processing in the right hemisphere could be due to the greater complexity of voice processing and to the difficulty of forming stable and well-structured representations, allowing to evaluate if a presented voice matches or not with an already known voice.

Detection of SARS-CoV-2 antibodies using commercial assays and seroconversion patterns in hospitalized patients.

OBJECTIVES: SARS-CoV-2 antibody assays are needed for serological surveys and as a complement to molecular tests to confirm COVID-19. However, the kinetics of the humoral response against SARS-CoV-2 remains poorly described and relies on the performance of the different serological tests. METHODS: In this study, we evaluated the performance of six CE-marked point-of-care tests (POC) and three ELISA assays for the diagnosis of COVID-19 by exploring seroconversions in hospitalized patients who tested positive for SARS-CoV-2 RNA. RESULTS: Both the ELISA and POC tests were able to detect SARS-CoV-2 antibodies in at least half of the samples collected seven days or more after the onset of symptoms. After 15 days, the rate of detection rose to over 80% but without reaching 100%, irrespective of the test used. More than 90% of the samples collected after 15 days tested positive using the iSIA and Accu-Tell® POC tests and the ID.Vet IgG ELISA assay. Seroconversion was observed 5 to 12 days after the onset of symptoms. Three assays suffer from a specificity below 90% (EUROIMMUN IgG and IgA, UNscience, Zhuhai Livzon). CONCLUSIONS: The second week of COVID-19 seems to be the best period for assessing the sensitivity of commercial serological assays. To achieve an early diagnosis of COVID-19 based on antibody detection, a dual challenge must be met: the immunodiagnostic window period must be shortened and an optimal specificity must be conserved.

Charge-Stripe Order and Superconductivity in Ir1-xPtxTe2.

A combined resistivity and hard x-ray diffraction study of superconductivity and charge ordering in Ir Ir1-xPtxTe2, as a function of Pt substitution and externally applied hydrostatic pressure, is presented. Experiments are focused on samples near the critical composition x c ~ 0.045 where competition and switching between charge order and superconductivity is established. We show that charge order as a function of pressure in Ir0.95Pt0.05Te2 is preempted - and hence triggered - by a structural transition. Charge ordering appears uniaxially along the short crystallographic (1, 0, 1) domain axis with a (1/5, 0, 1/5) modulation. Based on these results we draw a charge-order phase diagram and discuss the relation between stripe ordering and superconductivity.

Staging of recent HIV-1 infection using Geenius rapid confirmatory assay compared to INNO-LIA, New Lav and Blot 2.2 assays.

BACKGROUND: Besides confirmation of HIV seropositivity, Western Blot (WB) assays play an important role for identification of recent infection based on incomplete antibody reactivity and lack of p31 band. OBJECTIVES: We evaluated the capacities of the Geenius™ HIV1/2 Confirmatory Assay (Bio-Rad), a new generation rapid confirmatory assay based on immune-chromatography and automated reading, for staging of HIV-1 infection. STUDY DESIGN: Sixteen samples collected during early HIV-1 infections (Fiebig stage III-VI) were tested using the Geenius assay, and compared to HIV Blot 2.2 WB assay (MP Diagnostics), New Lav Blot I WB assay (Bio-Rad) and INNO-LIA™ HIV I/II Score Dot Blot assay (Fujirebio). Results obtained with Geenius and INNO LIA in 47 newly diagnosed chronic HIV-1 infections were also compared. RESULTS: The p24 band was less frequently detected in early HIV-1 infections using the Geenius (3/16) compared to the New Lav (15/16, p<0.0001), INNO-LIA (13/16, p=0.0011), and Blot 2.2 (13/16, p=0.0011). Testing samples collected during chronic infection allowed to confirm that p31 band and complete Gag, Pol, Env profiles were less frequently observed using the Geenius assay compared to the INNO LIA assay (p=0.027 for p31, and p=0.0015 for complete profile). CONCLUSIONS: The Geenius assay is a simple and rapid test showing a high sensitivity to detect Env bands and to confirm HIV-1 seropositivity during the early phases of infection. However, this test is less suitable for distinguishing between later stages of acute and chronic infections because of a reduced sensitivity to detect the p31 and p24 bands compared to INNO LIA and New Lav assays.

Selective Probing of Hidden Spin-Polarized States in Inversion-Symmetric Bulk MoS_{2}.

Spin- and angle-resolved photoemission spectroscopy is used to reveal that a large spin polarization is observable in the bulk centrosymmetric transition metal dichalcogenide MoS_{2}. It is found that the measured spin polarization can be reversed by changing the handedness of incident circularly polarized light. Calculations based on a three-step model of photoemission show that the valley and layer-locked spin-polarized electronic states can be selectively addressed by circularly polarized light, therefore providing a novel route to probe these hidden spin-polarized states in inversion-symmetric systems as predicted by Zhang et al. [Nat. Phys. 10, 387 (2014).NPAHAX1745-247310.1038/nphys2933].

Upper critical field, pressure-dependent superconductivity and electronic anisotropy of Sm4Fe2As2Te(1-x)O(4-y)F(y).

We present a detailed study of the electrical transport properties of a recently discovered iron-based superconductor: Sm4Fe2As2Te0.72O2.8F1.2. We followed the temperature dependence of the upper critical field by resistivity measurement of single crystals in magnetic fields up to 16 T, oriented along the two main crystallographic directions. This material exhibits a zero-temperature upper critical field of 90 T and 65 T parallel and perpendicular to the Fe2As2 planes, respectively. An unprecedented superconducting magnetic anisotropy γH=H(c2)(ab)/H(c2)(c) ~ 14 is observed near Tc, and it decreases at lower temperatures as expected in multiband superconductors. Direct measurement of the electronic anisotropy was performed on microfabricated samples, showing a value of ρ(c)/ρ(ab)(300K) ~ 5 that rises up to 19 near Tc . Finally, we have studied the pressure and temperature dependence of the in-plane resistivity. The critical temperature decreases linearly upon application of hydrostatic pressure (up to 2 GPa) similarly to overdoped cuprate superconductors. The resistivity shows saturation at high temperatures, suggesting that the material approaches the Mott-Ioffe-Regel limit for metallic conduction. Indeed, we have successfully modelled the resistivity in the normal state with a parallel resistor model that is widely accepted for this state. All the measured quantities suggest strong pressure dependence of the density of states.

Neural correlates of the semantic interference effect: new evidence from transcranial direct current stimulation.

In two experiments, we combined a semantic blocked naming paradigm with anodal transcranial direct current stimulation (tDCS) to shed light on the neural correlates of the semantic interference (SI) effect. In particular, prior to the naming task, anodal tDCS was applied over the left superior temporal gyrus (STG, Experiment 1) or the left inferior frontal gyrus (IFG, Experiment 2) to enhance cortical excitability in these regions. In both experiments, participants were tested in two sessions in which either real or sham tDCS was delivered. We found that anodal tDCS over the left STG significantly increased the SI effect, whereas anodal tDCS over the left IFG led to a reduction of the SI effect. Overall, our data confirm the existence of a distributed cortical network involved in lexical retrieval and show that both the left IFG and the left STG play a causal role in this process. In particular, the left IFG is likely to be critical in resolving the conflict between competitor lexical representations, while the left STG seems to be the neural locus of the lexical representational system, where competition among different lexical representations occurs.

Transcranial direct current stimulation over Broca's region improves phonemic and semantic fluency in healthy individuals.

Previous studies have demonstrated that transcranial direct current stimulation (tDCS) can be proficiently used to modulate attentional and cognitive functions. For instance, in the language domain there is evidence that tDCS can fasten picture naming in both healthy individuals and aphasic patients, or improve grammar learning. In this study, we investigated whether tDCS can be used to increase healthy subjects' performance in phonemic and semantic fluency tasks, that are typically used in clinical assessment of language. Ten healthy individuals performed a semantic and a phonemic fluency task following anodal tDCS applied over Broca's region. Each participant underwent a real and a sham tDCS session. Participants were found to produce more words following real anodal tDCS both in the phonemic and in the semantic fluency. Control experiments ascertained that this finding did not depend upon unspecific effects of tDCS over levels of general arousal or attention or upon participants' expectations. These data confirm the efficacy of tDCS in transiently improving language functions by showing that anodal stimulation of Broca's region can enhance verbal fluency. Implications of these results for the treatment of language functions in aphasia are considered.