Antiferromagnetic ordering in a 90 K copper oxide superconductor

Using elastic neutron scattering, we evidence a commensurate antiferromagnetic Cu(2) order (AF) in the superconducting (SC) high-$\rm T_c$ cuprate $\rm YBa_2(Cu_{1-y}Co_y)_3O_{7+\delta}$ (y=0.013, $\rm T_c$=93 K). As in the Co-free system, the spin excitation spectrum is dominated by a magnetic resonance peak at 41 meV but with a reduced spectral weight. The substitution of Co thus leads to a state where AF and SC cohabit showing that the CuO$_2$ plane is a highly antiferromagnetically polarizable medium even for a sample where T$_c$ remains optimum.Comment: 3 figure

Martensitic transition and magnetoresistance in a Cu-Al-Mn shape memory alloy. Influence of aging

We have studied the effect of ageing within the miscibility gap on the electric, magnetic and thermodynamic properties of a non-stoichiometric Heusler Cu-Al-Mn shape-memory alloy, which undergoes a martensitic transition from a $bcc$-based ($\beta$-phase) towards a close-packed structure ($M$-phase). Negative magnetoresistance which shows an almost linear dependence on the square of magnetization with different slopes in the $M$- and $\beta$-phases, was observed. This magnetoresistive effect has been associated with the existence of Mn-rich clusters with the Cu$_2$AlMn-structure. The effect of an applied magnetic field on the martensitic transition has also been studied. The entropy change between the $\beta$- and $M$-phases shows negligible dependence on the magnetic field but it decreases significantly with annealing time within the miscibility gap. Such a decrease is due to the increasing amount of Cu$_2$MnAl-rich domains that do not transform martensitically.Comment: 9 pages, 9 figures, accepted for publication in PR

Serendipitous alkylation of a Plk1 ligand uncovers a new binding channel

We obtained unanticipated synthetic byproducts from alkylation of the δ[superscript 1] nitrogen (N3) of the histidine imidazole ring of the polo-like kinase-1 (Plk1) polo-box domain (PBD)-binding peptide PLHSpT. For the highest-affinity byproduct, bearing a C[subscript 6]H[subscript 5](CH[subscript 2])[subscript 8]– group, a Plk1 PBD cocrystal structure revealed a new binding channel that had previously been occluded. An N-terminal PEGylated version of this peptide containing a hydrolytically stable phosphothreonyl residue (pT) bound the Plk1 PBD with affinity equal to that of the non-PEGylated parent but showed markedly less interaction with the PBDs of the two closely related proteins Plk2 and Plk3. Treatment of cultured cells with this PEGylated peptide resulted in delocalization of Plk1 from centrosomes and kinetochores and in chromosome misalignment that effectively induced mitotic block and apoptotic cell death. This work provides insights that might advance efforts to develop Plk1 PBD-binding inhibitors as potential Plk1-specific anticancer agents.National Institutes of Health (U.S.) (Grant GM60594)National Institutes of Health (U.S.) (Grant GM68762)National Institutes of Health (U.S.) (Grant CA112967

Ultrafast laser micro-nano structuring of transparent materials with high aspect ratio

Ultrafast lasers are ideal tools to process transparent materials because they spatially confine the deposition of laser energy within the material's bulk via nonlinear photoionization processes. Nonlinear propagation and filamentation were initially regarded as deleterious effects. But in the last decade, they turned out to be benefits to control energy deposition over long distances. These effects create very high aspect ratio structures which have found a number of important applications, particularly for glass separation with non-ablative techniques. This chapter reviews the developments of in-volume ultrafast laser processing of transparent materials. We discuss the basic physics of the processes, characterization means, filamentation of Gaussian and Bessel beams and provide an overview of present applications

Erratum: The solar orbiter radio and plasma waves (RPW) instrument (Astronomy and Astrophysics (2020) 642 (A12) DOI: 10.1051/0004-6361/201936214)

The erratum concerns Fig. 9 entitled "Antenna radio-electrical properties" for which some of the parameters are not correct. The new figure with new parameters is provided in Fig. 1 of this corrigendum. Fig. 1. Corrected Antenna radio-electrical properties. (Figure Presented)

The Athena X-ray Integral Field Unit: a consolidated design for the system requirement review of the preliminary definition phase

Instrumentatio

Functional outcomes in symptomatic versus asymptomatic patients undergoing incisional hernia repair: Replacing one problem with another? A prospective cohort study in 1312 patients

Background: Incisional hernias can be associated with pain or discomfort. Surgical repair especially mesh reinforcement, may likewise induce pain. The primary objective was to assess the incidence of pain after hernia repair in patients with and without pre-operative pain or discomfort. The secondary objectives were to determine the preferred mesh type, mesh location and surgical technique in minimizing postoperative pain or discomfort. Materials and methods: A registry-based prospective cohort study was performed, including patients undergoing incisional hernia repair between September 2011 and May 2019. Patients with a minimum follow-up of 3–6 months were included. The incidence of hernia related pain and discomfort was recorded perioperatively. Results: A total of 1312 patients were included. Pre-operatively, 1091 (83%) patients reported pain or discomfort. After hernia repair, 961 (73%) patients did not report pain or discomfort (mean follow-up = 11.1 months). Of the pre-operative asymptomatic patients (n = 221), 44 (20%, moderate or severe pain: n = 14, 32%) reported pain or discomfort after mean follow-up of 10.5 months. Of those patients initially reporting pain or discomfort (n = 1091), 307 (28%, moderate or severe pain: n = 80, 26%) still reported pain or discomfort after a mean follow-up of 11.3 months postoperatively. Conclusion: In symptomatic incisional hernia patients, hernia related complaints may be resolved in the majority of cases undergoing surgical repair. In asymptomatic incisional hernia patients, pain or discomfort may be induced in a considerable number of patients due to surgical repair and one should be aware if this postoperative complication

Femtosecond laser micromachining of fused silica molds

The use of low-energy femtosecond laser beam combined with chemical etching has been proven to be an efficient method to fabricate three-dimensional structures in fused silica. For high-volume application, this technology – like other serial processes – suffers from a moderate production rate. Here, we show that femtosecond laser can also be employed to fabricate silica molds and other patterned surfaces, including surfaces with high aspect ratio features (> 10). Through appropriate tailoring of silica’s surface property and subsequent creation of, for instance, simple elastomeric molding, new opportunities for the indirect 3D, multi-scale spatial characterization of deep laser-fabricated microstructures come along. We demonstrate that those moldings are characterized by a high fidelity (down to the nanometer scale) to the silica mold. These results further advance the applicability of femtosecond laser processing to glass

Positive exchange bias in ferromagnetic- ferrimagnetic bilayers: FeSn/FeGd

International audiencePositive exchange bias is shown to occur in (ferromagnetic (FeSn)/ferrimagnetic (FeGd)) bilayers. As the net magnetisation in the ferrimagnetic layer is not zero, in contrast to "regular" exchange bias observed in ferro/antiferromagnetic systems, we could detect the magnetic configuration of both layers by magnetisation, ac-susceptibility and resistivity measurements. The results allow us to conclude that the exchange bias effect is due to an antiferromagnetic coupling at the interface between the magnetisation of the layers through a domain wall located at the interface. The influence of this magnetic domain wall on transport and ac-susceptibility is presented