Severe COVID-19 Is Marked by a Dysregulated Myeloid Cell Compartment.

Coronavirus disease 2019 (COVID-19) is a mild to moderate respiratory tract infection, however, a subset of patients progress to severe disease and respiratory failure. The mechanism of protective immunity in mild forms and the pathogenesis of severe COVID-19 associated with increased neutrophil counts and dysregulated immune responses remain unclear. In a dual-center, two-cohort study, we combined single-cell RNA-sequencing and single-cell proteomics of whole-blood and peripheral-blood mononuclear cells to determine changes in immune cell composition and activation in mild versus severe COVID-19 (242 samples from 109 individuals) over time. HLA-DRhiCD11chi inflammatory monocytes with an interferon-stimulated gene signature were elevated in mild COVID-19. Severe COVID-19 was marked by occurrence of neutrophil precursors, as evidence of emergency myelopoiesis, dysfunctional mature neutrophils, and HLA-DRlo monocytes. Our study provides detailed insights into the systemic immune response to SARS-CoV-2 infection and reveals profound alterations in the myeloid cell compartment associated with severe COVID-19.

Genome-Wide Allele Frequency Changes Reveal That Dynamic Metapopulations Evolve Differently.

Two important characteristics of metapopulations are extinction-(re)colonization dynamics and gene flow between subpopulations. These processes can cause strong shifts in genome-wide allele frequencies that are generally not observed in "classical" (large, stable, and panmictic) populations. Subpopulations founded by one or a few individuals, the so-called propagule model, are initially expected to show intermediate allele frequencies at polymorphic sites until natural selection and genetic drift drive allele frequencies toward a mutation-selection-drift equilibrium characterized by a negative exponential-like distribution of the site frequency spectrum. We followed changes in site frequency spectrum distribution in a natural metapopulation of the cyclically parthenogenetic pond-dwelling microcrustacean Daphnia magna using biannual pool-seq samples collected over a 5-yr period from 118 ponds occupied by subpopulations of known age. As expected under the propagule model, site frequency spectra in newly founded subpopulations trended toward intermediate allele frequencies and shifted toward right-skewed distributions as the populations aged. Immigration and subsequent hybrid vigor altered this dynamic. We show that the analysis of site frequency spectrum dynamics is a powerful approach to understand evolution in metapopulations. It allowed us to disentangle evolutionary processes occurring in a natural metapopulation, where many subpopulations evolve in parallel. Thereby, stochastic processes like founder and immigration events lead to a pattern of subpopulation divergence, while genetic drift leads to converging site frequency spectrum distributions in the persisting subpopulations. The observed processes are well explained by the propagule model and highlight that metapopulations evolve differently from classical populations.

Sex-specific Genetic Determinants of Right Ventricular Structure and Function.

RATIONALE: While sex differences in right heart phenotypes have been observed, the molecular drivers remain unknown. OBJECTIVES: To provide biological insights into sex differences in the structure and function of the right ventricle (RV) using common genetic variation. METHODS: RV phenotypes were obtained from cardiac magnetic resonance imaging in 18,156 women and 16,171 men from the UK Biobank. Observational analyses and sex-stratified genome-wide association studies were performed. Candidate female-specific loci were evaluated against invasively measured cardiac performance in 479 female patients with idiopathic or heritable pulmonary arterial hypertension (PAH), recruited to the UK NIHR BioResource Rare Diseases study. MEASUREMENTS AND MAIN RESULTS: Sex was associated with differences in RV volumes and ejection fraction in models adjusting for left heart counterparts, blood pressure, lung function and sex hormone levels. Six genome-wide significant loci (13%) revealed heterogeneity of allelic effects between women and men, and significant sex-by-genotype interaction. These included two sex-specific candidate loci present in women only: a locus for RV ejection fraction in BMPR1A and a locus for RV end-systolic volume near DMRT2. Epigenetic data in RV tissue indicate that variation at the BMPR1A locus likely alters transcriptional regulation. In female patients with PAH, a variant located in the promoter of BMPR1A was significantly associated with cardiac index (effect size 0.16 l/min/m2), despite similar RV afterload. CONCLUSIONS: BMPR1A has emerged as a biologically plausible candidate gene for female-specific genetic determination of RV function, showing associations with cardiac performance under chronically increased afterload in female patients with PAH.

Probing Surface Transformations of Lanthanum Nickelate Electrocatalysts during Oxygen Evolution Reaction.

Monitoring the spontaneous reconstruction of the surface of metal oxides under electrocatalytic reaction conditions is critical to identifying the active sites and establishing structure-activity relationships. Here, we report on a self-terminated surface reconstruction of Ruddlesden-Popper lanthanum nickel oxide (La2NiO4+δ) that occurs spontaneously during reaction with alkaline electrolyte species. Using a combination of high-resolution scanning transmission electron microscopy (HR-STEM), surface-sensitive X-ray photoelectron spectroscopy (XPS), and soft X-ray absorption spectroscopy (sXAS), as well as electrochemical techniques, we identify the structure of the reconstructed surface layer as an amorphous (oxy)hydroxide phase that features abundant under-coordinated nickel sites. No further amorphization of the crystalline oxide lattice (beyond the ∼2 nm thick layer formed) was observed during oxygen evolution reaction (OER) cycling experiments. Notably, the formation of the reconstructed surface layer increases the material's oxygen evolution reaction (OER) activity by a factor of 45 when compared to that of the pristine crystalline surface. In contrast, a related perovskite phase, i.e., LaNiO3, did not show noticeable surface reconstruction, and also no increase in its OER activity was observed. This work provides detailed insight into a surface reconstruction behavior dictated by the crystal structure of the parent oxide and highlights the importance of surface dynamics under reaction conditions.

Goal-directed colloid versus crystalloid therapy and microcirculatory blood flow following ischemia/reperfusion.

OBJECTIVE: Ischemia/reperfusion can impair microcirculatory blood flow. It remains unknown whether colloids are superior to crystalloids for restoration of microcirculatory blood flow during ischemia/reperfusion injury. We tested the hypothesis that goal-directed colloid - compared to crystalloid - therapy improves small intestinal, renal, and hepatic microcirculatory blood flow in pigs with ischemia/reperfusion injury. METHODS: This was a randomized trial in 32 pigs. We induced ischemia/reperfusion by supra-celiac aortic-cross-clamping. Pigs were randomized to receive either goal-directed isooncotic hydroxyethyl-starch colloid or balanced isotonic crystalloid therapy. Microcirculatory blood flow was measured using Laser-Speckle-Contrast-Imaging. The primary outcome was small intestinal, renal, and hepatic microcirculatory blood flow 4.5 h after ischemia/reperfusion. Secondary outcomes included small intestinal, renal, and hepatic histopathological damage, macrohemodynamic and metabolic variables, as well as specific biomarkers of tissue injury, renal, and hepatic function and injury, and endothelial barrier function. RESULTS: Small intestinal microcirculatory blood flow was higher in pigs assigned to isooncotic hydroxyethyl-starch colloid therapy than in pigs assigned to balanced isotonic crystalloid therapy (768.7 (677.2-860.1) vs. 595.6 (496.3-694.8) arbitrary units, p = .007). There were no important differences in renal (509.7 (427.2-592.1) vs. 442.1 (361.2-523.0) arbitrary units, p = .286) and hepatic (604.7 (507.7-701.8) vs. 548.7 (444.0-653.3) arbitrary units, p = .376) microcirculatory blood flow between groups. Pigs assigned to colloid - compared to crystalloid - therapy also had less small intestinal, but not renal and hepatic, histopathological damage. CONCLUSIONS: Goal-directed isooncotic hydroxyethyl-starch colloid - compared to balanced isotonic crystalloid - therapy improved small intestinal, but not renal and hepatic, microcirculatory blood flow in pigs with ischemia/reperfusion injury. Whether colloid therapy improves small intestinal microcirculatory blood flow in patients with ischemia/reperfusion needs to be investigated in clinical trials.

Implications for the Hydrogenation of Propyne and Propene with Parahydrogen due to the in†situ Transformation of Rh2C to Rh0/C.

NMR spectroscopy studies using parahydrogen-induced polarization have previously established the existence of the pairwise hydrogen addition route in the hydrogenation of unsaturated hydrocarbons over heterogeneous catalysts, including those based on rhodium (Rh0). This pathway requires the incorporation of both hydrogen atoms from one hydrogen molecule to the same product molecule. However, the underlying mechanism for such pairwise hydrogen addition must be better understood. The involvement of carbon, either in the form of carbonaceous deposits on the surface of a catalyst or as a metal carbide phase, is known to modify catalytic properties significantly and thus could also affect the pairwise hydrogen addition route. Here, we explored carbon's role by studying the hydrogenation of propene and propyne with parahydrogen on a Rh2C catalyst and comparing the results with those for a Rh0/C catalyst obtained from Rh2C via H2 pretreatment. While the catalysts Rh2C and Rh0/C differ notably in the rate of conversion of parahydrogen to normal hydrogen as well as in terms of hydrogenation activity, our findings suggest that the carbide phase does not play a significant role in the pairwise H2 addition route on rhodium catalysts.

An investigation of the structural and electronic origins of enhanced chemical looping air separation performance of B-site substituted SrFe1-xCoxO3-δ perovskites.

Chemical looping air separation (CLAS) is a promising process intensification technology for extracting oxygen from air for oxygen enrichment in process streams. Co-doped strontium ferrites (SrFe1-xCoxO3-δ) have been found to have outstanding activities for CLAS processes. In this study, we explore the underlying factors driving the enhancement in oxygen uptake and release performance of perovskite structured SrFe1-xCoxO3-δ oxygen carriers for CLAS. Phase-pure perovskites, with B site substituted by up to 75 mol% Co, were prepared by a sol-gel method and systematically investigated through a wide range of well controlled experimental and computational approaches. While all SrFe1-xCoxO3-δ oxygen carriers showed excellent cyclic stability and structural reversibility over CLAS cycles, increased B site occupancy by Co resulted in monotonic decrease in onset temperature for oxygen release and increase in oxygen carrying capacity. These experimental trends can be fundamentally explained by an increase in the structural tolerance factor, an elevation in transition metal d-band, as well as an increased degree of hybridization between the metal d-band and the O p band. Therefore, these ab initio structural and electronic descriptors are useful design rationales for the hypothesis-driven synthesis of high-performing oxygen carriers for CLAS.

Changes in the Use of Hydrochlorothiazide and Other Antihypertensive Drugs in Switzerland in Association With the Swissmedic Safety Alert Regarding Non-melanoma Skin Cancer: An Interrupted Time-Series Analysis Using Swiss Claims Data.

PURPOSE: Long-term use of hydrochlorothiazide increases the risk of non-melanoma skin cancer. We aimed to evaluate potential changes in the use of hydrochlorothiazide in Switzerland after a direct healthcare professional communication (DHPC) in November 2018 by Swissmedic. METHODS: We performed interrupted time-series analyses using a large Swiss healthcare claims database (2015-2021). Within monthly intervals, we quantified the total number of claims and the total dispensed 'defined daily doses' (DDD) for preparations containing (1) hydrochlorothiazide, (2) angiotensin-converting enzyme (ACE) inhibitors and angiotensin-II-receptor blockers (ARB), (3) calcium-channel blockers (CCB) and (4) thiazide-like diuretics per 10 000 persons. Using segmented linear regression, we quantified the pre-DHPC trend, the immediate change and the post-DHPC change in trend for total claims and DDD for the four drug classes weighted for the demographic distribution of the Swiss population. RESULTS: ACE inhibitors and ARB were the most frequently claimed antihypertensive drugs with 300-400 claims per 10 000 persons, which increased by 5.4% during the study period. The average number of hydrochlorothiazide claims (157/10 000 persons in 2015) declined by 35% between 2015 and 2021. The decrease started prior to the DHPC, but the DHPC was associated with an immediate 6.1% decline and an accelerated decline in claims over time after the DHPC (similar results for DDD). This coincided with a 23% increase in claims of CCB (dihydropyridine type) over 7 years, whereas use of other antihypertensives increased less. CONCLUSION: Our results suggest that the DHPC by Swissmedic in 2018 accelerated a pre-existing decline in the use of hydrochlorothiazide in Switzerland.

Interoperable workflows by exchanging grid-based data between quantum-chemical program packages.

Quantum-chemical subsystem and embedding methods require complex workflows that may involve multiple quantum-chemical program packages. Moreover, such workflows require the exchange of voluminous data that go beyond simple quantities, such as molecular structures and energies. Here, we describe our approach for addressing this interoperability challenge by exchanging electron densities and embedding potentials as grid-based data. We describe the approach that we have implemented to this end in a dedicated code, PyEmbed, currently part of a Python scripting framework. We discuss how it has facilitated the development of quantum-chemical subsystem and embedding methods and highlight several applications that have been enabled by PyEmbed, including wave-function theory (WFT) in density-functional theory (DFT) embedding schemes mixing non-relativistic and relativistic electronic structure methods, real-time time-dependent DFT-in-DFT approaches, the density-based many-body expansion, and workflows including real-space data analysis and visualization. Our approach demonstrates, in particular, the merits of exchanging (complex) grid-based data and, in general, the potential of modular software development in quantum chemistry, which hinges upon libraries that facilitate interoperability.

Ingrown Toenails: A Survey Among Dermatologists on Current Treatments.

BACKGROUND: To date, there is no formal consensus on how to treat ingrown toenails. Despite the risk of causing irreparable damage to the nail, highly invasive procedures are still common. Less-invasive, matrix-directed techniques with shorter downtime and high cure rates exist, but, perhaps because of a lack of awareness, appear not to have been universally adopted. OBJECTIVE: The authors' study sought to generate data on common practices in the treatment of ingrown toenails. MATERIALS AND METHODS: The authors developed and conducted an online survey to ask dermatologists/dermatosurgeons how they would proceed in 9 different cases of ingrown toenails based on photographs. RESULTS: The authors received 154 replies. Nonsurgical interventions, including advice on nail care/foot baths/ointments/wraps/padding, were always the most frequently chosen option. Removal of the lateral nail plate followed by chemical partial matricectomy (phenolization) was the most or second-most frequently chosen surgical intervention. The answers were highly heterogeneous, and there was no unanimity based on morphology alone. CONCLUSION: Except for a preference for nonsurgical interventions, the authors could not identify any clear treatment standards. The heterogeneity of treatment approaches suggests the need for a guideline.

Current Perspectives on Type 3 Macular Neovascularization due to Age-Related Macular Degeneration.

BACKGROUND: The aim of this review was to systematically summarize the current knowledge on type 3 macular neovascularization (MNV3) in age-related macular degeneration (AMD). SUMMARY: Recent histopathologic and multimodal imaging findings led to the consensus definition of the new term "type 3 macular neovascularization" in AMD. MNV3 originates in the deep vascular plexus as a neovascular process without connection with the retinal pigment epithelium in the initial stages. This type has numerous clinical and pathomorphologic features that separate it from the other two types of MNV in AMD. Besides, its frequency appears to be higher than previously thought. In optical coherence tomography (OCT), MNV3 can be classified into stages 1-3. Hyperreflective foci in the outer retina possibly represent a precursor lesion. In addition, MNV3 is characterized by a strong association with reticular pseudodrusen, a high rate of bilaterality, close associations with advanced age and arterial hypertension, decreased choroidal thickness, and decreased choriocapillaris flow signals. Data from latest anti-vascular endothelial growth factor studies in MNV3 suggest that the OCT biomarkers in intraretinal and subretinal fluids should be interpreted differently than in the other types. Additionally, data from MNV3 eyes should be analyzed separately, allowing optimal type-specific treatment strategies in the future. KEY MESSAGES: This review highlights the need for accurate characterization of neovascular AMD lesions and an MNV type-specific approach, particularly for MNV3.

Clinical Landscape of Central Serous Chorioretinopathy in Germany: Retina.net CSC Registry Report Number 1.

INTRODUCTION: The German Registry of central serous chorioretinopathy (CSC) collects data on CSC patients in a nationwide multicenter approach to analyze epidemiology, risk factors, clinical presentations, as well as diagnosis and treatment patterns. METHODS: In this multicenter cohort study, patients with CSC were enrolled in nine tertiary referral centers in Germany between January 2022 and June 2023. After consenting to the study, demographic data, risk factors, reported symptoms, best-corrected visual acuity (BCVA), funduscopic findings, disease severity, and diagnostic and treatment decisions were recorded and analyzed. RESULTS: A total of 539 eyes of 411 CSC patients were enrolled in this study including 308 males (75%) and 103 females (25%). Patients were predominantly of Caucasian origin and had a mean age of 55.5 years (IQR 41.0-70.0). 28% of eyes were classified as acute (<4 months duration) CSC, 28% as chronic (>4 months duration) CSC, 21% as inactive CSC, 11% as chronic atrophic CSC, and 12% as CSC with secondary CNV. 128 patients (31%) demonstrated bilateral CSC. The most common risk factors reported were psychological stress (52%), smoking (38%), arterial hypertension (38%), and a history of or current use of steroids (30%). Most frequently encountered symptoms included decreased visual acuity (76%), metamorphopsia (49%), relative scotoma (47%), blurred vision (19%), and dyschromatopsia (9%). The mean logMAR BCVA on initial examination was 0.2 (≈20/30, IQR 0.2-0.4) but showed significant variation with a tendency of lower BCVA in chronic cases. At the baseline visit, 74% of the overall cohort received no treatment, while 19% underwent local treatment and only 2% underwent systemic treatment. Of the local therapies, anti-VEGF injections were the most frequently performed procedure (33%, mainly for secondary CNV), followed by micropulse laser (28%), focal nonpulsed laser (23%), verteporfin photodynamic therapy (14%), and nonsteroidal anti-inflammatory eye drops (2%). Among intravitreal anti-VEGF agents, aflibercept was used most frequently, followed by bevacizumab and ranibizumab. CONCLUSION: This registry represents one of the largest cohorts of European patients with CSC to date. Patient age and the proportion of women were higher than expected and bilateral active disease was lower than anticipated, highlighting that neither age nor gender should be overemphasized when diagnosing CSC. Therapeutic interventions are heterogeneous and include verteporfin photodynamic therapy, micropulse laser, and anti-VEGF injections in case of secondary CNV.

Peering into buried interfaces with X-rays and electrons to unveil MgCO3 formation during CO2 capture in molten salt-promoted MgO.

The addition of molten alkali metal salts drastically accelerates the kinetics of CO2 capture by MgO through the formation of MgCO3 However, the growth mechanism, the nature of MgCO3 formation, and the exact role of the molten alkali metal salts on the CO2 capture process remain elusive, holding back the development of more-effective MgO-based CO2 sorbents. Here, we unveil the growth mechanism of MgCO3 under practically relevant conditions using a well-defined, yet representative, model system that is a MgO(100) single crystal coated with NaNO3 The model system is interrogated by in situ X-ray reflectometry coupled with grazing incidence X-ray diffraction, scanning electron microscopy, and high-resolution transmission electron microscopy. When bare MgO(100) is exposed to a flow of CO2, a noncrystalline surface carbonate layer of ca. 7-Å thickness forms. In contrast, when MgO(100) is coated with NaNO3, MgCO3 crystals nucleate and grow. These crystals have a preferential orientation with respect to the MgO(100) substrate, and form at the interface between MgO(100) and the molten NaNO3 MgCO3 grows epitaxially with respect to MgO(100), and the lattice mismatch between MgCO3 and MgO is relaxed through lattice misfit dislocations. Pyramid-shaped pits on the surface of MgO, in proximity to and below the MgCO3 crystals, point to the etching of surface MgO, providing dissolved [Mg2+…O2-] ionic pairs for MgCO3 growth. Our studies highlight the importance of combining X-rays and electron microscopy techniques to provide atomic to micrometer scale insight into the changes occurring at complex interfaces under reactive conditions.

Effect of Compression Dressing After Upper Eyelid Blepharoplasty on Edema, Ecchymosis, Pain and Ocular Surface Irritation.

PURPOSE: To investigate the effect of a compression dressing (CD) on edema, ecchymosis, aesthetic outcome, pain, and ocular surface irritation after upper eyelid blepharoplasty. METHODS: We conducted a case-control study. Bilateral blepharoplasty was performed on both upper eyelids at the same time in patients with dermatochalasis. One side was randomized for CD. Edema and ecchymosis were scored at a 4-point rating scale by a blinded observer 1 day (D1), 1 week (D7), and 8 weeks (D56) after surgery; the same for scar formation regarding redness and bulging at D7 and D56. Aesthetic outcome was evaluated by the patient and blinded observer using the global aesthetic improvement score at D1, D7, and D56. Postoperative pain was scored by the patients using a visual analogue scale (0 to 10) at D1. At D1 patients had to state which side they felt more comfortable. RESULTS: Edema, scar formation and aesthetic outcome evaluated by the patient and blinded observer did not differ between the 2 sides on any of the survey days (p > 0.05). The median degree of ecchymosis was slightly higher on the lids without CD at D1 (1 [0-2] vs. 1.5 [0-2]; p = 0.495) and D7 (0 [0-2] vs. 0.5 [0-2]; p = 0.183), but not statistically significant. Postoperative pain was similar regardless to the use of CD (p = 0.925). The majority (55%) found the side without CD more comfortable. There was no case of corneal erosion and corneal staining was similar in both groups (p > 0.05). CONCLUSIONS: Using a CD after blepharoplasty shows no advantages regarding postoperative edema, ecchymosis, scar formation, or aesthetic results in the early postoperative period. As most patients preferred the noncovered side, CD can be omitted after blepharoplasty without inferiority for the postoperative results. CLINICAL TRIAL REGISTRY: NCT06111170.

Telephone follow-up after outpatient nail surgery - a retrospective analysis.

BACKGROUND: One of the areas of care in dermatosurgery is the surgical treatment of diseases of the nail organ. Side effects and complications after nail surgery were investigated by telephone follow-up (TFU), and its suitability for postoperative monitoring and consultation was assessed. PATIENTS AND METHODS: All patients who underwent nail surgery at the Department of Dermatology at the Ludwigshafen City Hospital from October 2019 to December 2021 in outpatient setting were contacted by telephone on the second to third postoperative day and questioned in a standardized manner about postoperative complaints and counselled if necessary. RESULTS: A total of 100 cases were followed up. The most common procedures performed were phenol matricectomy (41%), nail avulsion (16%), and nail matrix biopsies (9%). 50% and 21% of patients reported pain on the day of the procedure and the day after surgery, respectively. After nail avulsion, pain was statistically significantly more frequently reported on the day following the procedure and pain medication was statistically significantly more frequently required (p  =  0.002). Serious adverse events did not occur after nail surgery. 10% of the respondents raised specific questions and needed counseling by TFU. CONCLUSIONS: All nail surgeries were well tolerated in the outpatient setting. Pain was the most common side effect, although only half of all patients reported pain on the day of surgery and only 21% on the day after the procedure. The TFU proved to be an effective and practical as well as easy to establish method for postoperative follow-up and consultation after outpatient nail surgery.

Biocatalytic Ether Lipid Synthesis by an Archaeal Glycerolprenylase.

Although ethers are common in secondary natural products, they are an underrepresented functional group in primary metabolism. As such, there are comparably few enzymes capable of constructing ether bonds in a general fashion. However, such enzymes are highly sought after for synthetic applications as they typically operate with higher regioselectivity and under milder conditions than traditional organochemical approaches. To expand the repertoire of well characterized ether synthases, we herein report on a promiscuous archaeal prenyltransferase from the scarcely researched family of geranylgeranylglyceryl phosphate synthases (GGGPSs or G3PSs). We show that the ultrastable Archaeoglobus fulgidus G3PS makes various (E)- and (Z)-configured prenyl glycerol ethers from the corresponding pyrophosphates while exerting perfect control over the configuration at the glycerol unit. Based on experimental and computational data, we propose a mechanism for this enzyme which involves an intermediary prenyl carbocation equivalent. As such, this study provides the fundamental understanding and methods to introduce G3PSs into the biocatalytic alkylation toolbox.

Genetic Drift Shapes the Evolution of a Highly Dynamic Metapopulation.

The dynamics of extinction and (re)colonization in habitat patches are characterizing features of dynamic metapopulations, causing them to evolve differently than large, stable populations. The propagule model, which assumes genetic bottlenecks during colonization, posits that newly founded subpopulations have low genetic diversity and are genetically highly differentiated from each other. Immigration may then increase diversity and decrease differentiation between subpopulations. Thus, older and/or less isolated subpopulations are expected to have higher genetic diversity and less genetic differentiation. We tested this theory using whole-genome pool-sequencing to characterize nucleotide diversity and differentiation in 60 subpopulations of a natural metapopulation of the cyclical parthenogen Daphnia magna. For comparison, we characterized diversity in a single, large, and stable D. magna population. We found reduced (synonymous) genomic diversity, a proxy for effective population size, weak purifying selection, and low rates of adaptive evolution in the metapopulation compared with the large, stable population. These differences suggest that genetic bottlenecks during colonization reduce effective population sizes, which leads to strong genetic drift and reduced selection efficacy in the metapopulation. Consistent with the propagule model, we found lower diversity and increased differentiation in younger and also in more isolated subpopulations. Our study sheds light on the genomic consequences of extinction-(re)colonization dynamics to an unprecedented degree, giving strong support for the propagule model. We demonstrate that the metapopulation evolves differently from a large, stable population and that evolution is largely driven by genetic drift.

Targeted Small-Molecule Identification Using Heartcutting Liquid Chromatography-Infrared Ion Spectroscopy.

Infrared ion spectroscopy (IRIS) can be used to identify molecular structures detected in mass spectrometry (MS) experiments and has potential applications in a wide range of analytical fields. However, MS-based approaches are often combined with orthogonal separation techniques, in many cases liquid chromatography (LC). The direct coupling of LC and IRIS is challenging due to the mismatching timescales of the two technologies: an IRIS experiment typically takes several minutes, whereas an LC fraction typically elutes in several seconds. To resolve this discrepancy, we present a heartcutting LC-IRIS approach using a setup consisting of two switching valves and two sample loops as an alternative to direct online LC-IRIS coupling. We show that this automated setup enables us to record multiple IR spectra for two LC-features from a single injection without degrading the LC-separation performance. We demonstrate the setup for application in drug metabolism research by recording six m/z-selective IR spectra for two drug metabolites from a single 2 µL sample of cell incubation extract. Additionally, we measure the IR spectra of two closely eluting diastereomeric biomarkers for the inborn error of metabolism pyridoxine-dependent epilepsy (PDE-ALDH7A1), which shows that the heartcutting LC-IRIS setup has good sensitivity (requiring ∼µL injections of ∼µM samples) and that the separation between closely eluting isomers is maintained. We envision applications in a range of research fields, where the identification of molecular structures detected by LC-MS is required.

A simple and consistent quantum-chemical fragmentation scheme for proteins that includes two-body contributions.

The Molecular Fractionation with Conjugate Caps (MFCC) method is a popular fragmentation method for the quantum-chemical treatment of proteins. However, it does not account for interactions between the amino acid fragments, such as intramolecular hydrogen bonding. Here, we present a combination of the MFCC fragmentation scheme with a second-order many-body expansion (MBE) that consistently accounts for all fragment-fragment, fragment-cap, and cap-cap interactions, while retaining the overall simplicity of the MFCC scheme with its chemically meaningful fragments. We show that with the resulting MFCC-MBE(2) scheme, the errors in the total energies of selected polypeptides and proteins can be reduced by up to one order of magnitude and relative energies of different protein conformers can be predicted accurately.

CO2 Capture at Medium to High Temperature Using Solid Oxide-Based Sorbents: Fundamental Aspects, Mechanistic Insights, and Recent Advances.

Carbon dioxide capture and mitigation form a key part of the technological response to combat climate change and reduce CO2 emissions. Solid materials capable of reversibly absorbing CO2 have been the focus of intense research for the past two decades, with promising stability and low energy costs to implement and operate compared to the more widely used liquid amines. In this review, we explore the fundamental aspects underpinning solid CO2 sorbents based on alkali and alkaline earth metal oxides operating at medium to high temperature: how their structure, chemical composition, and morphology impact their performance and long-term use. Various optimization strategies are outlined to improve upon the most promising materials, and we combine recent advances across disparate scientific disciplines, including materials discovery, synthesis, and in situ characterization, to present a coherent understanding of the mechanisms of CO2 absorption both at surfaces and within solid materials.