Search

Exploring platinum (Pt)-solute nanoparticles (NPs) with multifaceted geometries, multifunctionality, and extended stability is key for several electrocatalytic applications. Here, we demonstrate that Pt-based alloy NPs modified with molybdenum (Mo) exhibit superior electrocatalytic properties compared with pure Pt NPs. Electrocatalytic testing of these Mo-modified Pt nanoalloys shows excellent catalytic performance in the hydrogen evolution reaction (HER), the oxygen reduction reaction (ORR), and the methanol oxidation reaction (MOR). We show that the catalytic functionalities in the ORR and the MOR achieved by the Mo-modified Pt nanoalloys are 15-25 times greater than the standard commercial Pt/C nanocatalyst. These nanoalloys also show enhanced resistance to poisoning by carbon monoxide (CO) adlayers and stability after accelerated durability tests (ADTs). We associate the origin of these exceptional electrocatalytic performances of the Pt-solute-Mo nanoalloys with their high degree of concavity, variations in vertex chemistry, and Pt enrichment along the corners and edges. Our findings offer a facile synthetic approach for the synthesis of Pt-solute nanoalloys as high-performance multifunctional electrocatalysts.

Galactose is a secondary fermentable sugar that requires specific regulatory and structural genes for its assimilation, which are under catabolite repression by glucose. When glucose is absent, the catabolic repression is attenuated, and the structural GAL genes are fully activated. In Saccharomyces cerevisiae, the GAL pathway is under selection in environments where galactose is present. However, it is unclear the adaptive strategies in response to long-term propagation in galactose as a sole carbon source in laboratory evolution experiments. Here, we performed a 4,000-generation evolution experiment using 48 diploid Saccharomyces cerevisiae populations to study adaptation in galactose. We show that fitness gains were greater in the galactose-evolved population than in identically evolved populations with glucose as a sole carbon source. Whole-genome sequencing of 96 evolved clones revealed recurrent de novo single nucleotide mutations in candidate targets of selection, copy number variations, and ploidy changes. We find that most mutations that improve fitness in galactose lie outside of the canonical GAL pathway. Reconstruction of specific evolved alleles in candidate target of selection, SEC23 and IRA1, showed a significant increase in fitness in galactose compared to glucose. In addition, most of our evolved populations (28/46; 61%) fixed aneuploidies on Chromosome VIII, suggesting a parallel adaptive amplification. Finally, we show greater loss of extrachromosomal elements in our glucose-evolved lineages compared with previous glucose evolution. Broadly, these data further our understanding of the evolutionary pressures that drive adaptation to less-preferred carbon sources.

Chronic thromboembolic pulmonary hypertension (CTEPH) is a rare complication of acute pulmonary embolism, either symptomatic or not. The occlusion of proximal pulmonary arteries by fibrotic intravascular material, in combination with a secondary microvasculopathy of vessels < 500 μm, leads to increased pulmonary vascular resistance and progressive right heart failure. The mechanism responsible for the transformation of red clots into fibrotic material remnants has not yet been elucidated. In patients with pulmonary hypertension, the diagnosis is suspected when a ventilation/ perfusion lung scan shows mismatched perfusion defects, and confirmed by right heart catheterisation and vascular imaging. Today, in addition to lifelong anticoagulation, treatment modalities include surgery, angioplasty and medical treatment according to the localisation and characteristics of the lesions. This statement outlines a review of the literature and current practice concerning diagnosis and management of CTEPH. It covers the definitions, diagnosis, epidemiology, follow-up after acute pulmonary embolism, pathophysiology, treatment by pulmonary endarterectomy, balloon pulmonary angioplasty, drugs and their combination, rehabilitation and new lines of research in CTEPH. It represents the first collaboration of the European Respiratory Society, the International CTEPH Association and the European Reference Network-Lung in the pulmonary hypertension domain. The statement summarises current knowledge, but does not make formal recommendations for clinical practice.

Background Treatment with monoclonal antibodies targeting circulating proprotein convertase subtilisin-kexin type 9 (PCSK9) was found to reduce all-cause mortality in addition to cardiovascular events, suggesting pleiotropic effects. Eicosanoids are bioactive metabolites involved in cardiovascular disease and have not yet been studied in the course of PCSK9 inhibition. Methods In this prospective translational single-center study, plasma samples were collected from 64 patients before and after initiation of PCSK9 inhibitor treatment. Metabolomic analyses were performed using liquid chromatography coupled to high-resolution mass spectrometry. Results A total of 62 bioactive eicosanoids were detected. Among the metabolites, four were significantly decreased by PCSK9 inhibition after one month and remained stable after 6 months (figure): arachidonic acid (p=0.003), 12,13-DiHOME (p Conclusion PCSK9 inhibition leads to significant changes in the eicosanoid profile already after one month, in particular to a downregulation of arachidonic acid. This discovery complements the presumed pleiotropic effects of PCSK9 inhibition and may provide additional benefit in the treatment of atherosclerotic disease. Funding Acknowledgement Type of funding sources: None.

Background Patients with acute myocardial infarction (AMI) frequently experience recurrent atherothrombotic events, largely attributable to non-culprit lesions with high-risk characteristics. Statins can halt the progression of coronary atherosclerosis, and addition of protein convertase subtilisin/kexin type 9-inhibitors (PCSK9i) results in incremental low-density lipoprotein cholesterol (LDL-C) lowering and atheroma regression. Purpose We sought to examine the interrelation between baseline imaging characteristics, on-treatment LDL-C levels, and changes in coronary atherosclerosis as assessed by serial, multi-modality intracoronary imaging in patients with AMI. Methods This is a post hoc analysis from the PACMAN-AMI randomized trial. Patients were randomly allocated to biweekly alirocumab 150 mg vs. placebo on top of high-intensity statin initiated within 24h of presentation with AMI, and underwent serial imaging of the two non-infarct-related arteries at baseline and after 52 weeks. The primary endpoint was percent atheroma volume (PAV) by intravascular ultrasound (IVUS). Powered secondary endpoints were maximal lipid core burden index (maxLCBI4mm) by near-infrared spectroscopy (NIRS) and minimum fibrous cap thickness (FCTmin) by optical coherence tomography (OCT). Results Of 300 randomized patients (mean age 58.5±9.8 years, 18.7% women, baseline LDL-C 3.94±0.87 mmol/L), IVUS was serially performed in 265 patients (537 arteries). LDL-C levels decreased to 1.92±0.79 mmol/L with placebo and 0.61±0.61 mmol/L with alirocumab (p Conclusion In this study of intensive LDL-C lowering treatment initiated in the acute AMI setting, more favorable plaque changes were observed in patients with lower on-treatment LDL-C levels and in lesions with more adverse baseline plaque characteristics. Whether AMI patients with high-risk plaque features might derive greater clinical benefit from early initiation of intensive LDL-C-lowering therapies requires further investigation. Funding Acknowledgement Type of funding sources: Private company. Main funding source(s): Sanofi, Regeneron

Understanding how genes interact is a central challenge in biology. Experimental evolution provides a useful, but underutilized, tool for identifying genetic interactions, particularly those that involve non-loss-of-function mutations or mutations in essential genes. We previously identified a strong positive genetic interaction between specific mutations in KEL1 (P344T) and HSL7 (A695fs) that arose in an experimentally-evolved Saccharomyces cerevisiae population. Because this genetic interaction is not phenocopied by gene deletion, it was previously unknown. Using “evolutionary replay” experiments we identified additional mutations that have positive genetic interactions with the kel1-P344T mutation. We replayed the evolution of this population 672 times from six timepoints. We identified 30 populations where the kel1-P344T mutation reached high frequency. We performed whole-genome sequencing on these populations to identify genes in which mutations arose specifically in the kel1-P344T background. We reconstructed mutations in the ancestral and kel1-P344T backgrounds to validate positive genetic interactions. We identify several genetic interactors with KEL1, we validate these interactions by reconstruction experiments, and we show these interactions are not recapitulated by loss-of-function mutations. Our results demonstrate the power of experimental evolution to identify genetic interactions that are positive, allele specific, and not readily detected by other methods, and sheds light on a previously under-explored region of the yeast genetic interaction network.

Lichens and bryophytes are abundant primary producers in high latitude and high elevation ecosystems, and they play an important role in ecosystem processes such as decomposition and nutrient cycling. Despite their importance, little is known about the decomposability of lichens and bryophytes either among or within species, at the whole community level, or how this decomposability is affected by their functional traits. Here, we studied decomposability of lichens and bryophytes at the community-level and individual species-level (using 21 species and genera) collected from an elevational gradient in alpine Norway. In order to isolate the elevation effect on litter quality, we used a standardized laboratory bioassay to measure decomposability. In contrast to our expectations, we found that community-level decomposability of lichens and bryophytes increased with elevation and thus decreasing temperature. In contrast, phosphorus release from the litter decreased with elevation while nitrogen release was unresponsive. Decomposability was explained by nutrient concentrations, litter pH and primary producer group identity (lichens versus bryophytes) at both the individual species and community levels. Species turnover (changes in species composition and abundance) was the main driver of decomposability across elevation at the community level, despite some of the traits explaining decomposability showing high intraspecific variability. Our study highlights the importance of among-species variation in determining lichen and bryophyte decomposability. Further, the higher decomposability that we found for higher elevations suggests that global warming might result in a shift towards slower decomposable lichen and bryophyte species.

Galactose is a secondary fermentable sugar that requires specific regulatory and structural genes for its assimilation, which are under catabolite repression by glucose. When glucose is absent, the catabolic repression is attenuated, and the structuralGALgenes are fully activated. InSaccharomyces cerevisiae, theGALpathway is under selection in environments where galactose is present. However, it is unclear the adaptive strategies in response to long-term propagation in galactose as a sole carbon source in laboratory evolution experiments. Here, we performed a 4,000-generation evolution experiment using 48 diploidSaccharomyces cerevisiaepopulations to study adaptation in galactose. We show that fitness gains were greater in the galactose-evolved population than in identically evolved populations with glucose as a sole carbon source. Whole-genome sequencing of 96 evolved clones revealed recurrentde novosingle nucleotide mutations in candidate targets of selection, copy number variations, and ploidy changes. We find that most mutations that improve fitness in galactose lie outside of the canonicalGALpathway and are involved in nutrient signaling. Reconstruction of specific evolved alleles in candidate target of selection,SEC23andIRA1, showed a significant increase in fitness in galactose compared to glucose. In addition, most of our evolved populations (28/46; 61%) fixed aneuploidies on Chromosome VIII, suggesting a parallel adaptive amplification. Finally, we show greater loss of extrachromosomal elements in our glucose-evolved lineages compared with previous glucose evolution. Broadly, these data further our understanding of the evolutionary pressures that drive adaptation to less-preferred carbon sources.

Identification of adaptive targets in experimental evolution typically relies on extensive replication and genetic reconstruction. An alternative approach is to directly assay all mutations in an evolved clone by generating pools of segregants that contain random combinations of evolved mutations. Here, we apply this method to 6 Saccharomyces cerevisiae clones isolated from 4 diploid populations that were clonally evolved for 2,000 generations in rich glucose medium. Each clone contains 17–26 mutations relative to the ancestor. We derived intermediate genotypes between the founder and the evolved clones by bulk mating sporulated cultures of the evolved clones to a barcoded haploid version of the ancestor. We competed the resulting barcoded diploids en masse and quantified fitness in the experimental and alternative environments by barcode sequencing. We estimated average fitness effects of evolved mutations using barcode-based fitness assays and whole-genome sequencing for a subset of segregants. In contrast to our previous work with haploid evolved clones, we find that diploids carry fewer beneficial mutations, with modest fitness effects (up to 5.4%) in the environment in which they arose. In agreement with theoretical expectations, reconstruction experiments show that all mutations with a detectable fitness effect manifest some degree of dominance over the ancestral allele, and most are overdominant. Genotypes with lower fitness effects in alternative environments allowed us to identify conditions that drive adaptation in our system.

The most common cause of human congenital disorders of glycosylation (CDG) are mutations in the phosphomannomutase gene PMM2, which affect protein N-linked glycosylation. The yeast gene SEC53 encodes a nearly-identical homolog of human PMM2. We evolved 384 populations of yeast harboring one of two human-disease-associated alleles, sec53-V238M and sec53-F126L, or wild-type SEC53. We find that after 1,000 generations, most populations compensate for the slow-growth phenotype associated with the sec53 human-disease-associated alleles. Through whole-genome sequencing we identify compensatory mutations, including known SEC53 genetic interactors. We observe an enrichment of compensatory mutations in other genes whose human homologs are associated with Type 1 CDG, including PGM1, which encodes the minor isoform of phosphoglucomutase in yeast. By genetic reconstruction, we show that evolved pgm1 mutations are dominant and allele-specific genetic interactors that restore both protein glycosylation and growth of yeast harboring the sec53-V238M allele. Finally, we characterize the enzymatic activity of purified Pgm1 mutant proteins. We find that reduction, but not elimination, of Pgm1 activity best compensates for the deleterious phenotypes associated with the sec53-V238M allele. Broadly, our results demonstrate the power of experimental evolution as a tool for identifying genes and pathways that compensate for human-disease associated alleles.

Identification of adaptive targets in experimental evolution typically relies on extensive replication and allele reconstructions. An alternative approach is to directly assay all mutations in an evolved clone by generating pools of segregants that contain random combinations of the evolved mutations. Here, we apply this method to 6 clones isolated from 4 diploid populations that were clonally evolved for 2,000 generations in rich glucose medium. Each clone contains ∼20-25 mutations relative to the ancestor. We derived intermediate genotypes between the founder and the evolved clones by bulk mating sporulated cultures of each evolved clone to a barcoded haploid version of the founder. We competed the barcoded segregants en masse and quantified the fitness of each barcode. We estimated average fitness effects of evolved mutations using barcode fitness and whole genome sequencing for a subset of segregants or time-course whole population whole genome sequencing. In contrast to our previous work in haploid populations, we find that diploids carry fewer evolved mutations with a detectable fitness effect (6%), contributing a modest fitness advantage (up to 5.4%). In agreement with theoretical expectations, reconstruction experiments show that all adaptive mutations manifest some degree of dominance over the ancestral allele, and most are overdominant. Competition assays under conditions that deviated from the evolutionary environment show that adaptive mutations are often pleiotropic.

Stroke associated with transcatheter aortic valve replacement (TAVR) is a potentially devastating complication. Until recently, the Sentinel™ Cerebral Protection System (CPS; Boston Scientific) has been the only commercially available device for mechanical prevention of TAVR-related stroke. However, its effectiveness is still undetermined. Methods Between January 2019 and August 2020 consecutive patients were randomly assigned to TAVR with or without Sentinel™ in a 1:1 fashion. We defined as primary endpoint clinically detectable cerebrovascular events within 72 hours after TAVR, and as secondary endpoints LOS and 12-month mortality. Logistic and linear regression analyses were used to assess associations of Sentinel™ use with endpoints. Results Of 411 patients (80±7 y/o, 47.4% female, EuroSCORE II 6.3±5.9%), Sentinel™ was used in 213 (51.8%), with both filters correctly deployed in 189 (46.0%). 20 (4.9%) cerebrovascular events were recorded, 10 (2.4%) of which were disabling strokes. Sentinel™ reduced cerebrovascular events in univariate analysis by 71% (OR 0.29, 95% CI 0.11–0.82; p=0.02) and after multivariate adjustment by 75% (adj. OR 0.25; 95% CI 0.08–0.80; p=0.02). Sentinel™ use was also significantly associated with shorter LOS (8.4±9.6 versus 6.7±6.1 days; p=0.03) and lower 12-month all-cause mortality (15.7% versus 7.5%, p=0.01). Conclusions In the present prospective all-comers TAVR cohort, Sentinel™ significantly 1) reduced cerebrovascular events, 2) shortened LOS, and 3) improved 12-month survival. These data promote the use of a CPS when implanting TAVR valves. Funding Acknowledgement Type of funding sources: None.

An empirical model is proposed for predicting layout dependent thickness variations in the semi-additive copper electrochemical plating (ECP) process. These variations are believed to be caused by the uneven depletion of copper sulfate during plating, causing low pattern density areas to plate faster than higher pattern density areas. Effective pattern density is extracted from the layout using a spatial filter and then mapped to the growth rates using a non-linear function. Test structures are designed that represent a wide range of feature sizes and pattern densities. After plating, these structures are profiled and used to fit the model, while other structures are used to validate its accuracy. Comparisons between the validation predictions and the experimental results show an average balanced root mean squared error (BRMSE) of 0.292 $\mu \text{m}$ , and a corresponding R2 value of 0.90. Fill patterns are then proposed and shown to control plating variations, by controlling pattern density. Finally, across-chip growth rate variations for a realistic interconnect layer are predicted, and experimentally confirmed.

ZusammenfassungDie Ende 2015 veröffentlichten ESC/ERS-Leitlinien und andere internationale Empfehlungen definierten die pulmonale Hypertonie (PH) bisher durch einen invasiv gemessenen mittleren pulmonal arteriellen Druck (mPAP) ≥ 25 mmHg in Ruhe. Auf dem 6th World Symposium on Pulmonary Hypertension in Nizza wurde eine Modifikation dieser hämodynamischen Definition im Sinne einer Senkung des Schwellenwertes auf > 20 mmHg vorgeschlagen. Für die präkapilläre PH wird zusätzlich ein pulmonaler Gefäßwiderstand (PVR) ≥ 3 Wood-Einheiten (WE) gefordert. Diese Änderung muss im Hinblick auf die zugrunde liegende Rationale und mögliche Konsequenzen kritisch hinterfragt werden; es bedarf daher einer eingehenden Erläuterung. Insbesondere muss klargestellt werden, dass diese Änderung aktuell keinen Einfluss auf die evidenzbasierte und zulassungskonforme Verschreibung von Medikamenten zur gezielten Therapie der pulmonal arteriellen Hypertonie (PAH) hat.