Explore the vast range of titles available.

The loss of water from Mars to space is thought to result from the transport of water to the upper atmosphere, where it is dissociated to hydrogen and escapes the planet. Recent observations have suggested large, rapid seasonal intrusions of water into the upper atmosphere, boosting the hydrogen abundance. We use the Atmospheric Chemistry Suite on the ExoMars Trace Gas Orbiter to characterize the water distribution by altitude. Water profiles during the 2018–2019 southern spring and summer stormy seasons show that high-altitude water is preferentially supplied close to perihelion, and supersaturation occurs even when clouds are present. This implies that the potential for water to escape from Mars is higher than previously thought.

The performance of lithium-ion batteries (LIBs) relies on the characteristics of the cathode material, including both intentionally applied coatings and naturally formed surface layers or binder adhesion. This study investigated the influence of the ion-permeable surface fraction, distribution, and characteristics of the coating on the performance of a lithium iron phosphate (LFP) electrode material. We developed an extended Newman-type half-cell model and examined the impact of coating parameters on the galvanostatic discharge curves of the LFP electrode material. The study found that the ion-permeable surface fraction has a significant influence on the diffusion and charge transfer characteristics of the electrode material. A decrease in the ion-permeable surface fraction leads to a decrease in the measured diffusion coefficients and to an increase in the overall coating resistance of the electrode material. Interestingly, the distribution of the ion-permeable surface also plays a role in the diffusion characteristics, with a coarsely dispersed coating resulting in lower diffusion coefficients. Additionally, the coating characteristics significantly affect the polarization and capacity of the electrode material at different C-rates. The model was used to approximate the experimental discharge curves of the LFP-based composite electrodes with two different compositions, and the simulated data showed satisfactory agreement with the experiment. Thus, we believe that the developed model and its further extension will be useful in numerical simulations that aim to facilitate the search for optimal compositions.

Prussian blue PB analogues (K;Mg)xM[Fe(CN)6] were obtained via the co-precipitation method. Manganese, iron, cobalt, nickel, copper and zinc were selected to obtain the metal hexacyanoferrates (MHCFs) of these metals and to systematically study their structural and electrochemical properties as cathode materials. The obtained substances were characterized via X-ray powder analysis, scanning electron microscopy, thermogravimetric analysis and elemental analysis. An electrochemical study of the obtained cathode materials relative to a platinum anode in an aqueous medium and a magnesium anode in a nonaqueous medium was carried out, and the cycling parameters were determined. The influence of 3d-metal nature on the composition–structure–properties of hexacyanoferrates was demonstrated. MHCFs are promising cathode materials for Mg2+ intercalation/deintercalation in aqueous electrolytes.

Peptides present an alternative modality to immunoglobulin domains or small molecules for developing therapeutics to either agonize or antagonize cellular pathways associated with diseases. However, peptides often suffer from poor chemical and physical stability, limiting their therapeutic potential. Disulfide-constrained peptides (DCP) are naturally occurring and possess numerous desirable properties, such as high stability, that qualify them as drug-like scaffolds for peptide therapeutics. DCPs contain loop regions protruding from the core of the molecule that are amenable to peptide engineering via direct evolution by use of phage display technology. In this study, we have established a robust platform for the discovery of peptide therapeutics using various DCPs as scaffolds. We created diverse libraries comprising seven different DCP scaffolds, resulting in an overall diversity of 2 x 10 11 . The effectiveness of this platform for functional hit discovery has been extensively evaluated, demonstrating a hit rate comparable to that of synthetic antibody libraries. By utilizing chemically synthesized and in vitro folded peptides derived from selections of phage displayed DCP libraries, we have successfully generated functional inhibitors targeting the HtrA1 protease. Through affinity maturation strategies, we have transformed initially weak binders against Notch2 with micromolar Kd values to high-affinity ligands in the nanomolar range. This process highlights a viable hit-to-lead progression. Overall, our platform holds significant potential to greatly enhance the discovery of peptide therapeutics.

Ubiquitin ligases are critical components of the ubiquitination process that determine substrate specificity and, in collaboration with E2 ubiquitin‐conjugating enzymes, regulate the nature of polyubiquitin chains assembled on their substrates. Cellular inhibitor of apoptosis (c‐IAP1 and c‐IAP2) proteins are recruited to TNFR1‐associated signalling complexes where they regulate receptor‐stimulated NF‐κB activation through their RING domain ubiquitin ligase activity. Using a directed yeast two‐hybrid screen, we found several novel and previously identified E2 partners of IAP RING domains. Among these, the UbcH5 family of E2 enzymes are critical regulators of the stability of c‐IAP1 protein following destabilizing stimuli such as TWEAK or CD40 signalling or IAP antagonists. We demonstrate that c‐IAP1 and UbcH5 family promote K11‐linked polyubiquitination of receptor‐interacting protein 1 (RIP1) in vitro and in vivo . We further show that TNFα‐stimulated NF‐κB activation involves endogenous K11‐linked ubiquitination of RIP1 within the TNFR1 signalling complex that is c‐IAP1 and UbcH5 dependent. Lastly, NF‐κB essential modifier efficiently binds K11‐linked ubiquitin chains, suggesting that this ubiquitin linkage may have a signalling role in the activation of proliferative cellular pathways. Canonical Lys48‐ and Lys63‐linked as well as non‐canonical linear polyubiquitin chains are involved in receptor‐mediated NF‐κB activation. This study identifies c‐IAP1‐generated Lys11‐linked chains, so far implicated only in cell‐cycle control and proteasome targeting, as an additional signal in this pathway.

The atmosphere of Mars has been studied for many years now by a long series of missions. The paper focuses on the results obtained by two of these that are led by European researchers overseen by the European Space Agency, i.e., Mars Express which was launched in 2003 and ExoMars Trace Gas Orbiter launched in 2016. Both missions are still providing high-quality data about the atmosphere of Mars, such as abundances of its key species – CO 2 , CO, H 2 O, O 3  - playing an important role in the different cycles existing on the planet, as well as other trace gases – O 2 (mixing ratio of 3.1 to 5.8 × 10 −3 above 90 km), the recently discovered HCl (up to 4 ppbv below 30 km), and the elusive CH 4 (stringent detection limit of 20 pptv). Some instruments are also sensitive enough to provide information on isotopologues of the key elements and have delivered for some of these the first and unique vertical profiles available today ( δ 13 C and δ 18 O in CO 2 and CO, D/H, δ 17 O and δ 18 O in water vapour). The paper retraces the history of the exploration of the Martian atmosphere putting the results from both missions in perspective.

The cellular inhibitor of apoptosis (c‐IAP) proteins are E3 ubiquitin ligases that are critical regulators of tumour necrosis factor (TNF) receptor (TNFR)‐mediated signalling. Through their E3 ligase activity c‐IAP proteins promote ubiquitination of receptor‐interaction protein 1 (RIP1), NF‐κB‐inducing kinase (NIK) and themselves, and regulate the assembly of TNFR signalling complexes. Consequently, in the absence of c‐IAP proteins, TNFR‐mediated activation of NF‐κB and MAPK pathways and the induction of gene expression are severely reduced. Here, we describe the identification of OTUB1 as a c‐IAP‐associated deubiquitinating enzyme that regulates c‐IAP1 stability. OTUB1 disassembles K48‐linked polyubiquitin chains from c‐IAP1 in vitro and in vivo within the TWEAK receptor‐signalling complex. Downregulation of OTUB1 promotes TWEAK‐ and IAP antagonist‐stimulated caspase activation and cell death, and enhances c‐IAP1 degradation. Furthermore, knockdown of OTUB1 reduces TWEAK‐induced activation of canonical NF‐κB and MAPK signalling pathways and modulates TWEAK‐induced gene expression. Finally, suppression of OTUB1 expression in zebrafish destabilizes c‐IAP (Birc2) protein levels and disrupts fish vasculature. These results suggest that OTUB1 regulates NF‐κB and MAPK signalling pathways and TNF‐dependent cell death by modulating c‐IAP1 stability. The deubiquitinase OTUB1 removes ubiquitin chains from c‐IAP1 within TWEAK receptor signalling complexes, to promote downstream activation of NF‐kB and MAPK pathways.

There was an error in the original publication [...]

This work is devoted to the study of exchange interactions between rare earth atoms in the LaAlO3 matrix. Using the magnetic dilution method, the study of concentration and temperature dependences of magnetic susceptibility and effective magnetic moments of diluted solid solutions the magnetic characteristics of single rare earth atoms and the character of superexchange between them are described—antiferromagnetic at low concentrations, and for samarium, predominantly ferromagnetic within greater clusters as the concentration increases. The development of superexchange is similar to the exchange between d-elements in the same matrix.

The atmosphere of Mars is enriched in heavy isotopes with respect to Earth as a result of the escape of the atmosphere to space over billions of years. Estimating this enrichment requires a rigorous understanding of all atmospheric processes that contribute to the evolution of isotopic ratios between the lower and upper atmosphere, where escape processes take place. We combine measurements of CO vertical profiles obtained by the Atmospheric Chemistry Suite on board the ExoMars Trace Gas Orbiter with the predictions of a photochemical model and find evidence of a process of photochemistry-induced fractionation that depletes the heavy isotopes of C and O in CO (δ13C = −160 ± 90‰ and δ18O = −20 ± 110‰). In the upper atmosphere, accounting for this process reduces the escape fractionation factor by ~25%, suggesting that less C has escaped from the atmosphere of Mars than previously thought. In the lower atmosphere, incorporation of this 13C-depleted CO fractionation into the surface could support the abiotic origin of recently found Martian organics.Measurements by the ExoMars Trace Gas Orbiter reveal a depletion of heavy CO isotopes in Mars’s atmosphere caused by photochemistry-induced fractionation. The observed depletion in heavy C has implications for our understanding of C escape to space and the formation of organic material on Mars’s surface.