Designing Active and Stable Silicon Photocathodes for Solar Hydrogen Production Using Molybdenum Sulfide Nanomaterials

Silicon is a promising photocathode for tandem photoelectrochemical water splitting devices, but efficient catalysis and long term stability remain key challenges. Here, it is demonstrated that with appropriately engineered interfaces, molybdenum sulfide nanomaterials can provide both corrosion protection and catalytic activity in silicon photocathodes. Using a thin MoS₂ surface protecting layer, MoS₂‐n⁺p Si electrodes that show no loss in performance after 100 h of operation are created. Transmission electron microscopy measurements show the atomic structure of the device surface and reveal the characteristics of the MoS₂ layer that provide both catalytic activity and excellent stability. In spite of a low concentration of exposed catalytically active sites, these electrodes possess the best performance of any precious metal‐free silicon photocathodes with demonstrated long term stability to date. To further improve efficiency, a second molybdenum sulfide nanomaterial, highly catalytically active [Mo₃S₁₃]^2? clusters, is incorporated. These photocathodes offer a promising pathway towards sustainable hydrogen production.     

Do nucleic acids moonlight as molecular chaperones?

Organisms use molecular chaperones to combat the unfolding and aggregation of proteins. While protein chaperones have been widely studied, here we demonstrate that DNA and RNA exhibit potent chaperone activity in vitro. Nucleic acids suppress the aggregation of classic chaperone substrates up to 300-fold more effectively than the protein chaperone GroEL. Additionally, RNA cooperates with the DnaK chaperone system to refold purified luciferase. Our findings reveal a possible new role for nucleic acids within the cell: that nucleic acids directly participate in maintaining proteostasis by preventing protein aggregation.     

Body temperature variation controls pre-mRNA processing and transcription of antiviral genes and SARS-CoV-2 replication

Antiviral innate immunity represents the first defense against invading viruses and is key to control viral infections, including SARS-CoV-2. Body temperature is an omnipresent variable but was neglected when addressing host defense mechanisms and susceptibility to SARS-CoV-2 infection. Here, we show that increasing temperature in a 1.5°C window, between 36.5 and 38°C, strongly increases the expression of genes in two branches of antiviral immunity, nitric oxide production and type I interferon response. We show that alternative splicing coupled to nonsense-mediated decay decreases STAT2 expression in colder conditions and suggest that increased STAT2 expression at elevated temperature induces the expression of diverse antiviral genes and SARS-CoV-2 restriction factors. This cascade is activated in a remarkably narrow temperature range below febrile temperature, which reflects individual, circadian and age-dependent variation. We suggest that decreased body temperature with aging contributes to reduced expression of antiviral genes in older individuals. Using cell culture and in vivo models, we show that higher body temperature correlates with reduced SARS-CoV-2 replication, which may affect the different vulnerability of children versus seniors toward severe SARS-CoV-2 infection. Altogether, our data connect body temperature and pre-mRNA processing to provide new mechanistic insight into the regulation of antiviral innate immunity.     

Chemical Communication in Necturus maculosus and his Cave-Living Relative Proteus anguinus (Proteidae,Urodela)

The chemical communication of the epigean Necturus maculosus and the cave-living Proteus anguinus are compared in laboratory conditions. In both species a specks-specific substance transferred by water could be shown, another was deposited on the substrate.     

A girl with karyotype 46,XX,del(7) (qter→p15:)

Summary A girl with partial deletion of the short arms of one chromosome 7 is described. Among many other symptoms she has craniosynostosis. Early closure of cranio-sutures has previously been described in 2 of 3 patients with partial deletion 7. Investigation of a number of genetic marker systems shows that the HL-A, MN, AcP, and GPT loci are not located in the deleted segment.

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Zusammenfassung Es wird ein Mädchen mit teilweiser Deletion des kurzen Armes eines Chromosoms 7 beschrieben. Außer vielen anderen Symptomen hat sie eine Craniosynostose. Frühzeitiger Verschluß der Schädelnähte wurde auch bei 2 von 3 Patienten mit Deletion 7, die in der Literatur beschrieben sind, beobachtet. Untersuchung einer Reihe genetischer Markersysteme zeigt, daß die HL-A-, MN-, AcP- und GPT-loci nicht in dem deletierten Segment liegen.