High-mobility compensated semimetals, orbital magnetization, and umklapp scattering in bilayer graphene moire superlattices

Twist-controlled moire superlattices (MS) have emerged as a versatile platform in which to realize artificial systems with complex electronic spectra. Bernal-stacked bilayer graphene (BLG) and hexagonal boron nitride (hBN) form an interesting example of the MS that has recently featured a set of unexpected behaviors, such as unconventional ferroelectricity and electronic ratchet effect. Yet, the understanding of the BLG/hBN MS electronic properties has, at present, remained fairly limited. Here we develop a multi-messenger approach that combines standard magnetotransport techniques with low-energy sub-THz excitation to get insights into the properties of this MS. We show that BLG/hBN lattice alignment results in the emergence of compensated semimetals at some integer fillings of the moire bands separated by van Hove singularities where Lifshitz transition occurs. A particularly pronounced semimetal develops when 8 electrons reside in the moire unit cell, where coexisting high-mobility electron and hole systems feature a strong magnetoresistance reaching 2350 % already at B=0.25 T. Next, by measuring the THz-driven Nernst effect in remote bands, we observe valley splitting, pointing to an orbital magnetization characterized by a strongly enhanced effective g-factor of 340. Last, using THz photoresistance measurements, we show that the high-temperature conductivity of the BLG/hBN MS is limited by electron-electron umklapp processes. Our multi-facet analysis introduces THz-driven magnetotransport as a convenient tool to probe the band structure and interaction effects in vdW materials and provides a comprehension of the BLG/hBN MS

COVID-19 patients share common, corticosteroid-independent features of impaired host immunity to pathogenic molds

Patients suffering from coronavirus disease-2019 (COVID-19) are susceptible to deadly secondary fungal infections such as COVID-19-associated pulmonary aspergillosis and COVID-19-associated mucormycosis. Despite this clinical observation, direct experimental evidence for severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2)-driven alterations of antifungal immunity is scarce. Using an ex-vivo whole blood stimulation assay, we challenged blood from twelve COVID-19 patients with Aspergillus fumigatus and Rhizopus arrhizus antigens and studied the expression of activation, maturation, and exhaustion markers, as well as cytokine secretion. Compared to healthy controls, T-helper cells from COVID-19 patients displayed increased expression levels of the exhaustion marker PD-1 and weakened A. fumigatus - and R. arrhizus -induced activation. While baseline secretion of proinflammatory cytokines was massively elevated, whole blood from COVID-19 patients elicited diminished release of T-cellular (e.g., IFN-γ, IL-2) and innate immune cell-derived (e.g., CXCL9, CXCL10) cytokines in response to A. fumigatus and R. arrhizus antigens. Additionally, samples from COVID-19 patients showed deficient granulocyte activation by mold antigens and reduced fungal killing capacity of neutrophils. These features of weakened anti-mold immune responses were largely decoupled from COVID-19 severity, the time elapsed since diagnosis of COVID-19, and recent corticosteroid uptake, suggesting that impaired anti-mold defense is a common denominator of the underlying SARS-CoV-2 infection. Taken together, these results expand our understanding of the immune predisposition to post-viral mold infections and could inform future studies of immunotherapeutic strategies to prevent and treat fungal superinfections in COVID-19 patients

Synthesis of air‐stable, odorless thiophenol surrogates via Ni‐Catalyzed C−S cross‐coupling

Thiophenols are versatile synthetic intermediates whose practical appeal is marred by their air sensitivity, toxicity and extreme malodor. Herein we report an efficient catalytic method for the preparation of S-aryl isothiouronium salts, and demonstrate that these air-stable, odorless solids serve as user-friendly sources of thiophenols in synthesis. Diverse isothiouronium salts featuring synthetically useful functionality are readily accessible via nickelcatalyzed C-S cross-coupling of (hetero)aryl iodides and thiourea. Convenient, chromatography-free isolation of these salts is achieved via precipitation, allowing the methodology to be translated directly to large scales. Thiophenols are liberated from the corresponding isothiouronium salts upon treatment with a weak base, enabling an in situ release / S-functionalization strategy that entirely negates the need to isolate, purify or manipulate these noxious reagent

Rotinas burocráticas e linguagens do estado: políticas de registros estatísticos criminais sobre mortes violentas no Rio de Janeiro e em Buenos Aires

Este artigo parte do interesse em produzir uma base de dados comparável das regiões metropolitanas do Rio de Janeiro e de Buenos Aires. Ao longo da pesquisa verificou-se que para atingir tal objetivo seria necessária a explicitação dos processos técnicos e das competências políticas que, no Brasil e na Argentina, deram lugar a modos específicos de produção de informação em matéria de criminalidade, com destaque às conjunturas particulares que levaram, em cada caso, a que os dados oficiais sobre criminalidade fossem objeto de disputas políticas, e à existência de conflitos intra e interinstitucionais. O que era, também, matéria de que se nutria a "opinião pública" quando o debate sobre a segurança pública ascendia no ranking da agenda pública. Tal abordagem permite concluir que as cifras falam mais sobre as instituições que a produziram do que sobre a criminalidade ou sobre a situação das mortes violentas nas regiões metropolitanas do Rio de Janeiro e de Buenos Aires. Portanto, neste artigo, tratar-se-á de apresentar como esses dados, para poderem ser considerados comparáveis entre regiões metropolitanas tão próximas e tão distantes como Buenos Aires e Rio de Janeiro, necessitaram ser (de)compostos e (des)agregados para poder-se compará-los e lê-los como indicadores de formas violentas de resolução de conflitos

To speak with the other's voice: reducing asymmetry and social distance in mental health care admission interviews

The aim of this article is to examine the case of adoption of characteristic features of the interlocutor's ‘voice’ in mental health care admission interviews at a public hospital in Buenos Aires, Argentina. We observed ethnographically that ‘speaking with the Other's voice’ is a strategy adopted by psychoanalysts to achieve clinical goals, though they overlook its wider implications and contradictions as it involves both professionals and patients. We will argue that patients adopt bureaucratic and psychiatric terms in order to decrease asymmetry and reorient the activity conducted between the professional and the client. On the other hand, professionals tend to consider social class, age, ethnicity or religion when adopting the patient's voice in an attempt to decrease social distance. These strategies are employed to accomplish different goals during the interview: to the patient, it is a way to show competence in the activity of medical consultation, indexing the highly valued voices of state institutions and psychiatric knowledge; to the professional, it is a strategy to achieve clinical goals by decreasing social distance and enhancing transference. Analysis will show the unequal distribution of voicing options for participants: while patients attempt to reduce asymmetry despite social distance, psychotherapists try to decrease social distance but maintain asymmetry. In conclusion, wider implications will be discussed for intergroup communication between professionals and clients.Fil: Bonnin, Juan Eduardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Saavedra 15. Centro de Estudios E Investigaciones Laborales; Argentin

Inducible Lung Epithelial Resistance Requires Multisource Reactive Oxygen Species Generation To Protect against Viral Infections

Viral pneumonias cause profound worldwide morbidity, necessitating novel strategies to prevent and treat these potentially lethal infections. Stimulation of intrinsic lung defenses via inhalation of synergistically acting Toll-like receptor (TLR) agonists protects mice broadly against pneumonia, including otherwise-lethal viral infections, providing a potential opportunity to mitigate infectious threats. As intact lung epithelial TLR signaling is required for the inducible resistance and as these cells are the principal targets of many respiratory viruses, the capacity of lung epithelial cells to be therapeutically manipulated to function as autonomous antiviral effectors was investigated. Our work revealed that mouse and human lung epithelial cells could be stimulated to generate robust antiviral responses that both reduce viral burden and enhance survival of isolated cells and intact animals. The antiviral protection required concurrent induction of epithelial reactive oxygen species (ROS) from both mitochondrial and dual oxidase sources, although neither type I interferon enrichment nor type I interferon signaling was required for the inducible protection. Taken together, these findings establish the sufficiency of lung epithelial cells to generate therapeutically inducible antiviral responses, reveal novel antiviral roles for ROS, provide mechanistic insights into inducible resistance, and may provide an opportunity to protect patients from viral pneumonia during periods of peak vulnerability.Viruses are the most commonly identified causes of pneumonia and inflict unacceptable morbidity, despite currently available therapies. While lung epithelial cells are principal targets of respiratory viruses, they have also been recently shown to contribute importantly to therapeutically inducible antimicrobial responses. This work finds that lung cells can be stimulated to protect themselves against viral challenges, even in the absence of leukocytes, both reducing viral burden and improving survival. Further, it was found that the protection occurs via unexpected induction of reactive oxygen species (ROS) from spatially segregated sources without reliance on type I interferon signaling. Coordinated multisource ROS generation has not previously been described against viruses, nor has ROS generation been reported for epithelial cells against any pathogen. Thus, these findings extend the potential clinical applications for the strategy of inducible resistance to protect vulnerable people against viral infections and also provide new insights into the capacity of lung cells to protect against infections via novel ROS-dependent mechanisms

Intense Saharan Dust Outbreak over the Iberian Peninsula in springtime 2021: Monitoring and Characterization of Transported Dust Particles

In spring 2021 an intense Saharan dust outbreak reached the Iberian Peninsula (IP), lasting from 26 March until 5 April. It was monitored at six lidar stations, belonging to either MPLNET or ACTRIS/EARLINET networks, covering thus almost all the IP extension. Polarized Micro-Pulse Lidar measurements were carried out at El Arenosillo/Huelva (ARN, Spain; 37.1ºN, 6.7ºW, 40 m a.s.l.), Torrejón de Ardoz (TRJ, Spain; 40.5º N, 3.5º W, 568 m a.s.l, which is not within MPLNET yet), and Barcelona (BCN, Spain; 41.4ºN, 2.1ºE, 125 m a.s.l.); and multi-wavelength Raman lidars measurements were performed at Granada (GRA, Spain; 37.1ºN, 3.6ºW, 680 m a.s.l.), Évora (EVO, Portugal; 38.6ºN, 7.9º W, 293 m a.s.l.), and Madrid (MAD, Spain; 40.5ºN, 3.7ºW, 680 m a.s.l.). Both particle backscatter coefficient (βp) and particle linear depolarization ratio (δp) profiles are retrieved for all the stations under cloud-free conditions. The optical properties (backscatter and extinction coefficients at 532 nm) for both the fine (Df) and coarse (Dc) dust components are separately derived by applying the POLIPHON (POlarisation LIdar PHOtometer Networking; Mamouri and Ansmann, 2014) approach. Additionally, the mass concentration profiles, the mass extinction efficiency and the height of the centre-of-mass for both fine and coarse-modes are also calculated for the overall period. Results are compared along with the evolution of the dust intrusion as it crosses the IP