Schiller International University

Harnessing light across soft interfaces remains a key challenge for designing biomimetic energy conversion systems. Here, we establish a DNA–liposome hybrid that extends light harvesting from the aqueous phase into the lipid membrane. Short DNA duplexes functionalized with fluorescein and cholesterol act as programmable antennas that anchor on the membrane surface and transfer energy to an embedded eosin Y acceptor. This arrangement enables controlled excitation transfer from water to the membrane interface, forming a compartmentalized nanoreactor that mimics natural photosynthetic assemblies. Spectroscopic analysis reveals efficient quenching of the fluorescein donor and static pre-association with the membrane acceptor. Complementary molecular dynamics simulations provide atomic-level insight into the orientation, distance, and flexibility of the DNA–chromophore construct, rationalizing the observed Förster-type energy transfer. This hybrid design represents, to our knowledge, the first demonstration of light harvesting across an aqueous–membrane boundary mediated by DNA architectures, offering a versatile platform for photo-triggered reactions and future energy-transfer cascades in synthetic cells.

Pseudomonas (P.) aeruginosa is a highly adaptable, opportunistic nosocomial pathogen that poses significant risks to public health and veterinary medicine. This bacterium carries a wide range of antimicrobial resistance (AMR) determinants and produces various virulence factors that enable it to invade hosts and increase disease severity. Recognised as a One Health pathogen, P. aeruginosa can be isolated from multiple sources, including humans, animals, food, and the environment. Despite its importance in clinical settings, there are still limited genomic and epidemiological data on P. aeruginosa isolates from companion animals in Germany. To address this knowledge gap, we conducted whole-genome sequencing (WGS) of 72 P. aeruginosa isolates collected in 2023 from various companion animals, including dogs, cats, horses, and rabbits, across Germany. Phenotypic antibiotic susceptibility testing (AST) showed that 97.2% of the isolates exhibited a multidrug-resistant (MDR) phenotype. The highest resistance rates were observed for cefotaxime (98.6%), followed by chloramphenicol (93.1%) and trimethoprim/sulfamethoxazole (87.5%). Fosfomycin resistance was observed in 26.4% of the isolates, despite all isolates carrying the fosA gene. All isolates were found to be susceptible to colistin at increased exposure levels. Resistance to imipenem was detected in four dog isolates. Genome analysis revealed various AMR genes associated with resistance to β-lactams, aminoglycosides, sulfonamides, fluoroquinolones, and phenicols. Multiple virulence-associated genes were also identified, including those involved in biofilm formation, adherence, motility, immune modulation, and exotoxin A production. Moreover, 27.8% of the isolates carried plasmid contigs, and one dog isolate harboured a class 1 integron. In silico multilocus sequence typing (MLST) assigned the 72 isolates to 59 distinct sequence types (STs), including five novel STs (ST5165–ST5169). The most frequently identified STs were ST253, ST258, ST395, and ST244, each represented by three isolates. Six high-risk clones (HRCs) of P. aeruginosa, including ST308, ST277, ST244, ST395, ST253, and ST274, were identified in dog (n = 8) and cat (n = 4) isolates. This study underscores the significant genomic diversity of P. aeruginosa circulating among companion animals and emphasises the need to manage this bacterium within a One Health framework.

The effects of porosity on the nanostructure and physiochemical properties of graphitic carbon nitride (g-C3N4) materials remain poorly understood both experimentally and theoretically. Here, three types of g-C3N4 materials with distinct morphologies, including layered, rod-like, and curved spherical structures, were investigated, showing significant variations in porosity, hydrophilicity, optical bandgap, charge transfer efficiency, and photocatalytic activity for oxygen reduction reaction to produce hydrogen peroxide (H2O2). Under 410 nm irradiation, the most porous material achieves a H2O2 yield of 2.7 mmol∙g-1∙L-1, representing a tenfold increase compared to the bulk g-C3N4. Three theoretical models are applied to investigate curvature effects, quantum size effects, and their combination. The curvature in g-C3N4 leads to an increase in the bandgap. Further, the formation of intrinsic micro-/meso-pores with curved/distorted surfaces is not feasible in g-C3N4 due to strong stacking interactions and the observed mesoporosity arises primarily from the nano-assembly of small crystallites rather than from curved surfaces. These findings deepen our understanding of porosity effects on the structure of g-C3N4 and highlight the importance of nanostructure design in optimizing g-C3N4 for photocatalytic applications.

Abstract Heterotrophic bacteria supply cobalt-containing cobalamin (Cbl) to marine microalgae, which in return provide organic substrates. Such metabolic cross-feeding can regulate the species composition of prolific marine plankton and biofilms. Algal-produced glycine betaine (GB) can be catabolized by bacteria using a Cbl-dependent demethylase (MtgBCD). Yet, GB’s impact on bacterial Cbl production during cross-feeding, and its control by cobalt scarcity remains elusive. Here, we demonstrate that Phaeobacter inhibens bacteria boost their Cbl production 25-fold when grown in monocultures with GB compared to glucose. During co-cultivation, P. inhibens satisfied the Cbl requirements of Gephyrocapsa huxleyi algae. Transcriptomic analysis of mono- and co-cultures revealed co-expression of mtgBCD and gbcAB genes encoding Cbl-dependent and -independent GB demethylases, respectively. Distinct growth defects of deletion mutants indicate that P. inhibens switches from Cbl-dependent to -independent GB demethylation under cobalt limitation, involving a Cbl riboswitch. Our findings suggest a positive feedback loop in which algal GB release stimulates the bacterial supply of Cbl. We predict the breakdown of this interaction under naturally occurring cobalt limitation which potentially contributes to the transient nature of algal blooms. Comparative genomics indicate that this mechanism is widespread in Rhodobacterales and other abundant marine Alphaproteobacteria , underscoring its pivotal role in global ocean productivity.

The incorporation of the natural photosynthetic apparatus into a (soft matter) environment highly restricts the number of degradation possibilities and furthermore enables targeted repair of key molecular components. Intrigued by this design-principle of the natural blueprint, we postulate that balancing the interplay between polymeric matrices and photocatalytically active centers prolongs and sustains photocatalytic activity as well as repair-capability in molecular artificial photosynthesis. There are few systems where active repair has been demonstrated, and one prominent example is the Ru(tpphz)PtI2 hydrogen-evolving photocatalyst, where hydrogenation of the pyrazine ring in the tpphz bridging ligand has been shown to lead to an end of photocatalytic activity. Subsequent in-situ repair by persulfate enabled catalyst reactivation, but so far at the cost of decreasing catalytic activity over several repair cycles. We now show that tailored polyampholytic graft copolymers allow to electrostatically immobilize the photocatalyst in a unimolecular soft matter matrix, can prolong (photo)catalytic activity, and facilitate active repair without significant loss of activity over several cycles. We attribute this to a decreased propensity for hydrogenation of the pyrazine ring and, with that, slower degradation of the bridge and improved long term HER activity, as evidenced by a holistic spectroscopic characterization of molecular and electronic structure of the photoredox catalyst. We therefore regard this as a novel blueprint for a synergistic molecule-in-matrix combination for sustainable light-driven catalysis.

Abstract Purpose Aqueous-deficient dry eye disease (ADDE) results from lacrimal gland dysfunction leading to tear film instability and chronic ocular surface inflammation. Despite the gland’s known regenerative potential, the intrinsic molecular mechanisms enabling epithelial recovery remain poorly understood. This study aimed to characterize intrinsic regeneration processes of murine lacrimal gland epithelial cells (mLGECs) and identify pathways with therapeutic potential. Methods Primary mLGECs were isolated from neonatal C57BL/6J mice and characterized by RT-PCR, immunocytochemistry, and β-hexosaminidase secretion assays. Acute injury was induced by brief exposure to 20% ethanol. Cell viability, apoptosis, and transcriptional responses were analyzed during early recovery phases. Pathway enrichment was conducted using Gene Ontology and KEGG annotations. Regeneration-associated growth factors were validated by quantitative PCR, ELISA, and functional assays assessing cell viability and wound closure in the presence or absence of the MAPK inhibitor SCH772984. Results Cultured mLGECs preserved epithelial and lacrimal-specific markers and maintained regulated secretory activity. RNA-seq two hours post-injury revealed robust activation of MAPK signaling, accompanied by strong upregulation of regenerative ligands including Hbegf, Areg, Ngf, and Gdnf. Transient protein induction of HBEGF and AREG was confirmed. Functionally, HBEGF, AREG, NGF, and GDNF markedly enhanced epithelial survival, ATP recovery, and wound closure, while MAPK inhibition abolished regeneration, demonstrating pathway dependence. Conclusion These results identify MAPK-dependent mechanisms as central to the intrinsic regenerative response of lacrimal gland epithelial cells following acute injury. HBEGF and AREG emerged as key mediators driving epithelial survival and proliferation. The findings provide a mechanistic basis for developing defined growth factor–based therapies as standardized, safe, and effective alternatives to blood-derived treatments for patients with severe ADDE.

Abstract Background Food-based dietary guidelines (FBDGs) provide recommendations on diets that aim to decrease disease risk and environmental impact, while remaining culturally acceptable for the population. Using mathematical optimization to define such diets, these objectives can be operationalized as components of the objective function. Objectives To develop a framework for (i) deriving an indicator that quantifies diet-related disease burden and (ii) evaluating different weighting schemes within a three-dimensional diet optimization model. Methods To address objective (i), disability-adjusted life years (DALYs) from the Global Burden of Disease Study (GBD) and a diet-specific burden estimate based on observational data were transformed into a model-compatible indicator using linear interpolation. To address objective (ii), a linear diet optimization model was developed. It included constraints on nutrients and acceptability, and a three-objective function that minimized disease burden (DALYs), environmental impact (greenhouse gas emissions and land use), and, as a proxy for cultural acceptability, deviation from the observed diet. Forty-two model variations with different weighting schemes were computed and compared regarding component outcomes. Results In proof-of-concept analyses, the derived health indicator aligned closely with values reported in the literature: 90% (based on GBD) and 99% (based on the observational data) of diet-related DALYs were captured. Among the 42 model variations, strong synergies were observed between health and environmental outcomes. Optimizing exclusively for disease burden or environmental impact resulted in substantial deviations from the observed diet, underscoring the importance of considering cultural acceptability. Model stability improved with the inclusion of all three components. Conclusion The proposed methodology enables the integration of DALYs and provides insights about various weighting schemes to establish a diet optimization model that minimizes disease burden, environmental impact, and deviation from the observed diet, and serves as the basis to derive FBDG for Germany.

Abstract In this paper, we introduce and investigate multivariate versions of frequent stability and diam-mean equicontinuity — called “frequent m -stability” and “diam-mean m -equicontinuity”, where $$m &gt; 1$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mi>m</mml:mi> <mml:mo>&gt;</mml:mo> <mml:mn>1</mml:mn> </mml:mrow> </mml:math> is a natural number. Here, “multivariate” refers to the dynamical behaviour of tuples of starting points. Systems for which the factor map to the maximal equicontinuous factor () is finite-to-one for a residual set — “almost finite-to-one extensions” — or a set of full measure — “almost-surely finite-to-one extensions” — are respectively characterised by these dynamical rigidity properties. In the case of a second-countable, locally compact, abelian acting group and a natural number m , a minimal system is frequently $$(m+1)$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mo>(</mml:mo> <mml:mi>m</mml:mi> <mml:mo>+</mml:mo> <mml:mn>1</mml:mn> <mml:mo>)</mml:mo> </mml:mrow> </mml:math> -stable if and only if it is an almost m -to-1 extension of its . Similarly, it is shown that a minimal system is diam-mean $$(m+1)$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mo>(</mml:mo> <mml:mi>m</mml:mi> <mml:mo>+</mml:mo> <mml:mn>1</mml:mn> <mml:mo>)</mml:mo> </mml:mrow> </mml:math> -equicontinuous if and only if it is an almost-surely m-to-1 extension of its .