Sign of inverse spin Hall voltages generated by ferromagnetic resonance and temperature gradients in yttrium iron garnet|platinum bilayers

We carried out a concerted effort to determine the absolute sign of the inverse spin Hall effect voltage generated by spin currents injected into a normal metal. We focus on yttrium iron garnet (YIG)|platinum bilayers at room temperature, generating spin currents by microwaves and temperature gradients. We find consistent results for different samples and measurement setups that agree with theory. We suggest a right-hand-rule to define a positive spin Hall angle corresponding to with the voltage expected for the simple case of scattering of free electrons from repulsive Coulomb charges.Comment: incorporated additions from the published versio

MicroRNA profiling of human primary macrophages exposed to dengue virus identifies miRNA-3614-5p as antiviral and regulator of ADAR1 expression

ABSTARCT: Due to the high burden of dengue disease worldwide, a better understanding of the interactions between dengue virus (DENV) and its human host cells is of the utmost importance. Although microRNAs modulate the outcome of several viral infections, their contribution to DENV replication is poorly understood. METHODS AND PRINCIPAL FINDINGS: We investigated the microRNA expression profile of primary human macrophages challenged with DENV and deciphered the contribution of microRNAs to infection. To this end, human primary macrophages were challenged with GFP-expressing DENV and sorted to differentiate between truly infected cells (DENV-positive) and DENV-exposed but non-infected cells (DENV-negative cells). The miRNAome was determined by small RNA-Seq analysis and the effect of differentially expressed microRNAs on DENV yield was examined. Five microRNAs were differentially expressed in human macrophages challenged with DENV. Of these, miR-3614-5p was found upregulated in DENV-negative cells and its overexpression reduced DENV infectivity. The cellular targets of miR-3614-5p were identified by liquid chromatography/mass spectrometry and western blot. Adenosine deaminase acting on RNA 1 (ADAR1) was identified as one of the targets of miR-3614-5p and was shown to promote DENV infectivity at early time points post-infection. CONCLUSION/SIGNIFICANCE: Overall, miRNAs appear to play a limited role in DENV replication in primary human macrophages. The miRNAs that were found upregulated in DENV-infected cells did not control the production of infectious virus particles. On the other hand, miR-3614-5p, which was upregulated in DENV-negative macrophages, reduced DENV infectivity and regulated ADAR1 expression, a protein that facilitates viral replication

Spin caloritronics in magnetic metals and insulators

The connection between heat and electricity is called thermoelectricity and was discovered long ago. It induces an electrical current when applying a temperature difference across an electrical conductor or leads to heating/cooling when sending an electrical current through the interface between two conductors. The research discussed in this thesis looks at how these thermoelectric effects behave in magnetic metals. We show that an interface between a magnetic and a non magnetic metal is cooled when sending in a magnetic polarized current. Furthermore we have demonstrated that it is possible to make a nanoscale heat switch by switching two magnetic layer, separated by a thin layer of copper. Thermoelectric effects are not observed in electrical insulators as no electrical current can flow. However, it is possible to observe magnetic thermoelectric effects because the magnetic moments of the electrons are able to interact. We show for the first time that by sending such a 'magnetic current' into a magnetic insulator heating or cooling is induced, depending on the magnetization direction. With the help of a computer model we are able to replicate the physical effects in our measurements to quantify what is happening even better

Glow-in-the-Dark Infectious Disease Diagnostics Using CRISPR-Cas9-Based Split Luciferase Complementation

Nucleic acid detection methods based on CRISPR and isothermal amplification techniques show great potential for point-of-care diagnostic applications. However, most current methods rely on fluorescent or lateral flow assay readout, requiring external excitation or postamplification reaction transfer. Here, we developed a bioluminescent nucleic acid sensor (LUNAS) platform in which target dsDNA is sequence-specifically detected by a pair of dCas9-based probes mediating split NanoLuc luciferase complementation. LUNAS is easily integrated with recombinase polymerase amplification (RPA), providing attomolar sensitivity in a rapid one-pot assay. A calibrator luciferase is included for a robust ratiometric readout, enabling real-time monitoring of the RPA reaction using a simple digital camera. We designed an RT-RPA-LUNAS assay that allows SARS-CoV-2 RNA detection without the need for cumbersome RNA isolation and demonstrated its diagnostic performance for COVID-19 patient nasopharyngeal swab samples. Detection of SARS-CoV-2 from samples with viral RNA loads of ∼200 cp/μL was achieved within ∼20 min, showing that RPA-LUNAS is attractive for point-of-care infectious disease testing

Effect of miR-181a, miR-4301, miR-3960 and miR-4508 on DENV infection of Huh7 cells.

<p>Huh7 cells were transfected with a mimic negative control (NC) and with the indicated miRNA mimics. At 24 hpt, cells were infected at MOIs 1, 5 and 10. The percentage of E-positive cells (grey bars) and infectious virus particle production (black bars) were determined at 24 hpi. The percentages of infection of cells transfected with the NC and infected at MOIs 1, 5 and 10 were 6.57±2.07; 13.9±3.48 and 18.53±2.64 respectively; while the viral titers were 1.2x10⁵±5x10⁴; 1.08x10⁶±2x10⁵ and 7.06 x10⁶±6x10⁴ PFU/ml respectively. Data is presented as the percentage relative to the NC and shows mean ± SEM from three independent experiments. Statistical differences were assessed with Student’s t-test.</p

ADAR KO MEFs are less permissive to DENV than wild-type MEFs.

<p>Wild-type (WT) MEFs, p53 KO MEFs (p53^-/-) and p53/ADAR double KO MEFs (ADAR^-/-) were infected with DENV at MOIs 1 and 5. At the indicated time points, the percentage of infection (upper panels) was determined by flow cytometry and the infectious virus particle production (lower panels) by plaque assay. Data shows mean ± SEM from three independent experiments.</p

Differentially expressed miRNAs in MDMs challenged with DENV.

<p>(A) MDMs obtained from three different blood donors (D28, D29 and D30) were treated as follows: 1) mock-infected and non-sorted, 2) treated with UVi-DENV, 3) challenged with GFP-DENV (DENV-challenge), 4) mock-infected and passed through the FACS sorter, 5) challenged with GFP-DENV and sorted for GFP positive cells (DENV-plus), 6) challenged with GFP-DENV and sorted for GFP negative cells (DENV-neg). (B) Hierarchical unsupervised Pearson correlation of miRNAs showing differentially expressed miRNAs across the samples (ANOVA, p<0.05). (C) Differentially expressed miRNAs across the samples after the Benjamini and Hochberg correction for multiple testing (p<0.05).</p

Validation of the miRNA expression profile.

<p>(A) miR-3960 and miR-4508 expression was determined by real-time PCR using specific primers for the mature form of the miRNAs. Fold changes of the respective comparisons were determined through the comparative Ct method taking into account the PCR efficiency and miRNA-16-5p as reference miRNA. Data is presented as mean ± SEM from three different blood donors. (B) Spearman correlation between the fold changes obtained by RNA sequencing and real-time PCR.</p