Local Environment Research Articles (Page 1)

The anaerobic bacterium Geobacter sulfurreducens produces extracellular, electronically conductive cytochrome polymer wires that are conductive over micron length scales. Structure models from cryo-electron microscopy data show OmcS wires form a linear chain of hemes along the protein wire axis, which is proposed as the structural basis supporting their electronic properties. However, the mechanism by which this heme arrangement supports long-range electronic conduction remains unknown. Structure models from cryo-electron microscopy data show these wires form a linear chain of hemes along the protein wire axis, which is proposed as the structural basis supporting their electronic properties. Existing computational models using static heme redox potentials and coupling energies fail to explain experimental observations, predicting conductances 10,000 to 100,000 times lower than measured values. Here, we investigate how dynamic disorder affects site energies, interheme coupling, and long-range electronic conductivity within these cytochrome wires. We introduce an approach to extract charge carrier site information directly from Kohn-Sham density functional theory, without employing projector schemes, and show that site and coupling energies are highly sensitive to changes in interheme geometry and the surrounding electrostatic environment. Unlike models that incorporate dynamic disorder as a thermally averaged quantity, our quantum charge carrier model incorporates proxies for dynamic disorder through decoherence corrections, yielding predicted diffusion coefficient closer to what is expected from experiment and comparable with other organic-based electronic materials. Based on these simulations, we propose that the instantaneous fluctuations of the local electrostatic environment can transiently lift energy degeneracies and delocalize charge carriers. These studies reveal how incorporating dynamic fluctuations associated with the environment resolves the discrepancy between theory and experiment in microbial cytochrome wires and highlight design principles for bioinspired, heme-based conductive materials.

Electrochemical CO2 conversion (ECC) has emerged as a promising strategy to address global carbon emissions while producing valuable fuels and chemicals. This mini review examines the fundamental mechanisms of CO2 reduction on catalytic surfaces, where the interplay between adsorption energies, intermediate stabilization, and charge transfer governs reaction pathways and selectivity. We systematically analyze the key factors determining catalyst performance, including surface electronic structure, active site coordination, and local microenvironment effects. The discussion highlights innovative strategies for enhancing ECC efficiency: (1) precise control of top coating on catalysts to optimize active sites and local reaction environment, and (2) rational engineering of reaction environments through electrolyte modulation and pH management. A dedicated focus is placed on surface coating techniques as a transformative approach-protective layers can simultaneously stabilize catalysts against reconstruction, tailor interfacial charge transfer, and mitigate competing reactions. By correlating recent advances in material design with mechanistic insights, this mini review provides a framework for developing next-generation ECC systems, bridging fundamental surface science with practical catalytic engineering.

G-quadruplex structures formed by human telomeric sequences are highly sensitive to subtle sequence variations and local environment. While most structural studies have focused on sequences containing four uninterrupted G-tracts, the structural consequences of splitting a G-tract remain unexplored. Here, we present the NMR solution structure of a human telomeric sequence with the first G-tract split. The structure adopts an antiparallel topology with a disordered GTT segment at the 5'-end. This conformation is preferentially formed at a biologically relevant double-strand/single-strand DNA junction. These findings broaden our understanding of the structural diversity of human telomeric G-quadruplexes.

Based on the influence of western education and thought patterns, it is a mammoth task to find unanimous agreement on what constitutes Indigenous Knowledge systems (IKS). It can be argued that it is impossible to obtain an unadulterated African Indigenous Knowledge because of colonialism which has been so long in place. However, critical issues can be unveiled and agreed upon that include the philosophy and practices of African Indigenous peoples. This article aims to unearth what constitutes African Indigenous Knowledge/education from the perspectives of some selected key education stakeholder in Zambia. To realise this aim, qualitative interviews were employed as data collection methods to have an in-depth understanding of the participants on the subject matter under contention. Selected key education stakeholders who included teachers, religious leader, traditional leaders and curriculum specialists were purposefully sampled across the country. The collected data was thematically analysed. The main findings of the study revealed that Indigenous knowledge is rooted in the Zambian culture and is based on native people’s living experiences. Emerging facets from the respondents therefore pointed to mutual agreement that indigenous knowledge encompasses local knowledge unique to Zambia’s culture, skills, beliefs, and practices developed over generations in harmony with the local environment and community This knowledge is of fluid nature translating continually changing, being produced or generated, as well as discovering, lost or recreated. The study recommends the need for a paradigm shift in curriculum development and implementation, one that recognises IK not only as an addition to the mainstream curriculum but as a legitimate and vital knowledge system.

The persistent problem of food insecurity has been a major global concern. Understanding the relationship between the food environment and how it affects food security is crucial for improving the overall health and well-being of the population. This study utilized secondary cross-sectional data from the 2016 Local Level Food Health and Nutrition Survey (LFHNS) conducted by the Department of Science and Technology- Food and Nutrition Research Institute (DOST-FNRI) in the Municipality of Pulilan, Bulacan. Logistic regression was used to determine the association between the density of food stores, perceived nutrition environment, and food security status. The study’s results showed no association between the density of food stores, perceived nutrition environment, and food security; however, a positive association was found with the number of food stores. Findings showed that for every unit increase in the number of food stores, an increase of 1.9 food-secure households (p=<0.05, 95% C.I. 1.3-2.7) was noted. The “sari-sari store” was the most common type of food store and the most accessible among the poor and poorest households. Further studies should include other food environment factors affecting food security, such as typology, proximity, and other food retail outlets available in the community, including traditional restaurants or carinderia and fast-food chains.

Abstract Tree diversity influences litter decomposition both directly, through changes in litter quality and composition, and indirectly, by altering the local decomposition environment (LDE). However, the role of the LDE in shaping litter decomposition rates remains less explored than the direct effects. A standardized decomposition experiment using cellulose and wood substrates was conducted over the course of a year across seven tree diversity experiments in Europe and North America to explore how tree diversity, through its influence on the LDE, impacts decomposition rates. Tree functional diversity enhanced the decomposition rate of high‐quality substrate (cellulose) but had no effect on the decomposition rate of low‐quality substrate (wood). The impact of LDE was context‐dependent, with decomposition rates being highest under favourable climatic conditions, such as moderate temperatures and high precipitation. Contrary to the common assumption that litter decomposes faster in broadleaved and arbuscular (AM)‐dominated stands, our findings show that decomposition was faster in mixtures containing coniferous species and ectomycorrhizal (EM)‐associated trees, suggesting that LDE plays a larger role than initially thought. Synthesis . This study highlights the crucial role of LDE in shaping decomposition rates. While tree functional diversity generally enhances decomposition under favourable climatic conditions, LDE played a more significant role than previously recognized in EM stands, suggesting that faster decomposition rates in AM stands are primarily due to litter quality. These findings emphasize the context‐dependent nature of decomposition and the importance of considering LDE in understanding how tree diversity influences decomposition processes.

Pneumonia caused by viral or bacterial pathogens such as SARS-CoV2 or Pseudomonas aeruginosa may result in life-threatening disease with a strong contribution of proteases' dysregulation. The present study aimed to systematically characterize the contribution of ADAM10 and ADAM17 on leukocytes and circulating exosomes to viral and bacterial pneumonia. The analysis of COVID-19 and bacterial pneumonia patient samples was combined with in vivo experiments in conditional knockout animals lacking either ADAM10 or ADAM17 in leukocytes and cell culture experiments for mechanistic studies. Hospitalized bacterial pneumonia and COVID-19 patients displayed a severity dependent increase of ADAM10 and ADAM17 activity on exosomes. These exosomes caused pathophysiological changes of cardiomyocytes and the endothelial barrier. In a preclinical murine pneumonia model, we observed that leukocytes contributed to this increase in exosomal proteolytic activity. In the local environment of the lung, ADAM10 orchestrated a pro-inflammatory response with M1 macrophage polarization, increased reactive oxygen species (ROS) generation, cytokine release, tissue damage and oedema formation, whereas ADAM17 seemed to dampen the initial inflammatory response to an anti-infective, ROS-balanced level. Leukocytic ADAM10 and ADAM17 and their release on exosomes may constitute relevant regulatory elements in bacterial and viral pneumonia, with a potential contribution of exosomes to disease progression and systemic inflammatory responses. Therefore, the diagnostic, prognostic, and therapeutic value of ADAM10 and ADAM17 should be evaluated in further preclinical and translational studies, addressing the changes of the immune response and exosomes as cargo vehicles both at local site and for the prevention of systemic effects.

Abstract The discovery of persistent radio sources (PRSs) associated with three repeating fast radio bursts (FRBs) has provided insight into the local environments of these FRBs. Here, we present deep radio observations of the fields surrounding three highly active repeating FRBs, namely, FRB 20220912A, FRB 20240114A, and FRB 20240619D, using the upgraded Giant Metrewave Radio Telescope at low radio frequencies. Toward FRB 20240114A, we report the detection of compact source at 650 MHz with a flux density of 65.6 ± 8.1 μ Jy beam −1 . Our measurements of the spectral index, star formation rate of the host galaxy, and recently reported constraints on the physical size strongly argue for our detected source to be a PRS associated with the FRB 20240114A. We investigate possible origins of the PRS associated with FRB 20240114A. Based on its brightness and age, we rule out central engines formed via accretion-induced collapse of a white dwarf, while superluminous supernovae, long gamma-ray bursts, and neutron star merger channels remain viable. An off-axis GRB afterglow could also explain the observed emission. For FRB 20220912A, we detect radio emission that is most likely due to star formation in the host galaxy. For FRB 20240619D, we provide upper limits on the radio emission from an associated PRS or the host galaxy. The detection of the PRS associated with FRB 20240114A is a useful addition to the PRSs known to be associated with only three other FRBs so far, and further supports the origin of the PRS in the form of magnetoionic medium surrounding the FRB sources.

Molecular fabrication of metal surfaces has potential to harness diverse surface processes, such as CO 2 electrolysis on copper. CO 2 reduction is influenced not only by the local environment of the active copper atom but also by the surface atomic order, surface dynamics under electrode polarization, and mass transport. CO 2 reduction on two types of Cu 2 O‐derived Cu metal, modified with chemically identical organic layers, is studied. Surface click chemistry enables uniform modification, precisely replicating the surface morphologies of 2D‐packed and dispersed nanocubic Cu 2 O. In both types of catalysts, the modification affects CO 2 reduction, but with markedly different selectivity. On 2D‐packed Cu 2 O, the modified organic layer forms two distinct functional domains, one promoting proton reduction and the other facilitating CO adsorption, on a continuous copper surface. These domains cooperatively promote the formation of C 2+ products. In modified nanocubic Cu 2 O, where a limited number of copper atoms are enclosed in the organic layer shell, the crystal regularity of reduced Cu is disrupted significantly inhibiting CC bond formation. Assisted by proton transport through organic layer, this surface instead selectively produces methane. These results highlight the multifunctional effects of molecular modification, which creates distinct yet cooperative domains and induces surface atom restructuring.

We present a comprehensive study of the structure, formation, and dynamics of a one-component model system that self-assembles into an icosahedral quasicrystal (IQC). Using molecular dynamics simulations combined with unsupervised machine learning techniques, we identify and characterize the unique structural motifs of IQCs, including icosahedral and dodecahedral arrangements, and quantify the evolution of local environments during the IQC formation process. Our analysis reveals that the formation of the IQC is driven by the emergence of distinct local clusters that serve as precursors to the fully developed quasicrystalline phase. In addition, we examine the dynamics of the system across a range of temperatures, identifying transitions from vibrationally restricted motion to activated diffusion and uncovering signatures of dynamic heterogeneity inherent to the quasicrystalline state. To directly connect structure and dynamics, we use a machine-learning-based order parameter to quantify the presence of distinct local environments across temperatures. We find that regions with high structural order, as captured by specific machine-learned classes, correlate with suppressed self-diffusion and minimal dynamical heterogeneity, consistent with phason-like motion within the IQC. In contrast, regions with lower structural order exhibit enhanced collective motion and increased dynamical heterogeneity. These results establish a quantitative framework for understanding the coupling between structural organization and dynamical processes in quasicrystals, providing new insights into the mechanisms governing IQC stability and dynamics.

X-ray absorption spectroscopy (XAS) provides critical insights into the molecular and electronic structures of complex condensed-phase systems. For example, the XAS spectrum of liquid water depends on the complex three-dimensional arrangements of water molecules and their effects on the core-to-valence electronic transitions. Consequently, a wealth of molecular and electronic information is encoded in the complex spectral patterns. To decode these structure-electronic property relationships, we simulated the XAS spectra of bulk water by combining advanced molecular dynamics (MD) simulations coupled with multiconfigurational wave function methods. Using three advanced MD approaches─ab initio MD (AIMD), RexPoN, and MB-pol─we sampled the local solvation environments and hydrogen-bond (HB) networks, which were then used to predict the XAS spectra. Based on the theory-experiment comparisons of pair distribution functions and XAS spectra, we identified the MD method that most reliably predicts the local water structure. We further revealed that the charge-transfer (CT) character observed across the entire spectral range is strongly correlated to the hydrogen-bond (HB) network. Specifically, the extent of CT and the associated excitation energy are significantly influenced by the HB structure. These findings highlight the limitations of a purely local excitation model for interpreting bulk water XAS spectra. Instead, accurate sampling of HB structures and high-level wave function theory with dynamic correlation are essential for reliable spectral interpretation. This approach provides new insights into the relationship between the electronic structure and the molecular organization of water.

Alkali metal cations play a critical role in determining the performance of various electrocatalytic systems by modulating the local reaction environment. In membrane electrode assembly (MEA) CO2 electrolysis systems, excessive cation crossover through ion-exchange membranes can result in salt precipitation. However, the mechanisms governing cation transport across these membranes under different operating current densities, as well as their accumulation at the catalytic interface and within the electrolyzer flow fields, are not fully understood. In this work, we investigate these phenomena using in situ X-ray fluorescence spectroscopy. Employing Cs+ as a model cation, we examine its transport across a representative anion exchange membrane (AEM, Sustainion) and cation exchange membrane (CEM, Nafion) under various operating regimes, including potential step-up, potential step-down, and pulsed potential conditions. We observe distinct variations in cation concentrations within the cathodic flow fields, depending on the applied operation mode, as well as clear differences in transport behavior between the AEM and CEM. Our results reveal that during pulsed potential operation with an AEM, cations accumulated at the catalytic interface can transiently diffuse into the cathodic flow field rather than crossing over to the anode. This behavior suggests that pulsed potential operation may, in fact, accelerate salt precipitation, underscoring the need for careful consideration when it is employed as a mitigation strategy.

Background: Emerging evidence links the local food environment to chronic disease outcomes, yet its relationship with cardiac mortality remains under explored at the population level. This study examines the association between the Retail Food Environment Index (RFEI), a marker of community food healthiness, and cardiac death rates across U.S. counties. Hypothesis: We propose that higher RFEI scores are significantly linked to greater cardiac mortality, independent of socioeconomic status, lifestyle behaviours, and demographic characteristics. Methods: A cross-sectional ecological study was conducted using county-level data from 2,793 U.S. counties, integrating cardiac mortality information from the CDC WONDER database for the years 2018–2020 and the food accessibility data from the USDA Food Environment Atlas. The primary outcome was age-adjusted cardiac mortality per 100,000 population. The main exposure variable was the Retail Food Environment Index (RFEI), defined as the ratio of fast-food outlets and convenience stores to supermarkets and farmers' markets. To test the robustness of the RFEI, two alternate indices (RFEI1 and RFEI2) were developed by varying the inclusion criteria for superstore classification. Descriptive statistics, along with univariable and multivariable regression analyses, were performed, adjusting for socioeconomic indicators, racial/ethnic composition, health behaviours, metabolic risk factors, and food accessibility. Results: The mean cardiac mortality rate was 246.6 per 100,000 (SD = 58.3). RFEI showed a positive association with cardiac mortality in both univariate (β = 1.75; 95% CI, 1.25–2.24; P < 0.001) and multivariable analyses (β = 0.96; 95% CI, 0.60–1.34; P < 0.001). RFEI1 and RFEI2 yielded consistent results (β = 2.17 and 2.37, respectively; both P < 0.001). Among covariates, smoking (β = 5.47; P < 0.001), diabetes (β = 2.26; P = 0.008), and poverty rate (β = 0.76; P = 0.008) were significant predictors. The final model explained 50% of the variation in mortality (adjusted R square = 0.50). Conclusion: A higher density of unhealthy food outlets is independently associated with increased cardiac mortality across U.S. counties. These findings underscore the importance of local food environments as modifiable population-level determinants of cardiovascular health and support public health strategies aimed at improving equitable access to nutritious food.

The Euclid Q1 fields were selected for calibration purposes in cosmology and are therefore relatively devoid of nearby galaxies. However, this is precisely what makes them interesting fields in which to search for dwarf galaxies in local density environments. We took advantage of the unprecedented depth, spatial resolution, and field of view of the Euclid Quick Release (Q1) to build a census of dwarf galaxies in these regions. We have identified dwarf galaxies in a representative sample of 25 contiguous tiles in the Euclid Deep Field North (EDF-N) covering an area of 14.25,deg^2. The dwarf galaxy candidates were identified using a semi-automatic detection method based on properties measured by the Euclid pipeline and released as part of the catalogue produced by the MERge Processing Function (MER PF) pipeline. A selection cut in surface brightness and magnitude was used to produce an initial dwarf candidate catalogue, and this was followed by a cut in morphology (removing background spirals) and IE-̋E colour (removing red ellipticals). This catalogue was then visually classified to produce a final sample of dwarf candidates, including their morphology, number of nuclei, globular cluster (GC) richness, and presence of a blue compact centre. We identified 2674 dwarf candidates, corresponding to 188 dwarfs per square degree. The visual classification of the dwarfs reveals a slightly uneven morphological mix of 58% ellipticals and 42% irregulars, with very few potentially GC-rich (1.0%) and nucleated (4.0%) candidates but a noticeable fraction (6.9%) of dwarfs with blue compact centres. The distance distribution of 388 (15%) of the dwarf candidates with spectroscopic redshifts peaks at about 400,Mpc. Their stellar mass distribution confirms that our selection effectively identifies dwarfs while minimising contamination. The most prominent dwarf overdensities are dominated by dwarf ellipticals, while dwarf irregulars are more evenly distributed across the field of view. This work highlights remarkable ability to detect and characterise dwarf galaxies across diverse masses, distances, and environments.

Background: Sweet corn (Zea mays L. saccharata) is a nutritionally rich maize type valued for its sweetness and global market demand. In Pakistan, limited research has focused on evaluating exotic germplasm for yield, stress tolerance, and adaptability, despite its potential to improve productivity and diversify cropping systems. Understanding genetic variability and heritability among key agronomic traits is fundamental for developing superior hybrids suited to local environments. Objective: The study aimed to evaluate the genetic diversity, heritability, and inter-trait associations among exotic sweet corn genotypes under Pakistan’s agro-climatic conditions, to identify superior parental combinations for breeding high-yielding hybrids. Methods: Four exotic inbred lines (YSC-811, WSC-602, WSC-99, WSC-01) and their eleven F₁ hybrids were evaluated in a randomized complete block design with three replications at the University of Agriculture, Faisalabad. Morphological and yield-related traits were recorded, including plant height, tassel length, cob weight, grain weight, and shelling percentage. Data were analyzed using ANOVA, correlation, and multivariate techniques (PCA and cluster analysis). Heritability and genetic coefficients of variation were estimated to determine the genetic control of traits. Results: Significant variation was observed among genotypes for yield and yield-contributing traits (p < 0.001). The hybrid YSC-811 × WSC-01 exhibited the highest cob weight (288.8 g) and grain weight (79.1 g), while WSC-602 displayed superior shelling efficiency (54.2 %). High heritability was found for cob weight (83.6 %), shelling percentage (83.1 %), and number of kernel rows per cob (78.3 %), suggesting strong additive gene action. Positive correlations between leaf traits and yield attributes (r = 0.71–0.92) indicated their potential as indirect selection indices. PCA revealed that the first two components accounted for 65.8 % of total variability, confirming distinct genotype groupings. Conclusion: The study demonstrated broad genetic diversity and identified YSC-811 × WSC-01 as a superior cross for yield improvement. The findings emphasize the potential of exotic germplasm for breeding resilient, high-yielding sweet corn adapted to Pakistan’s agro-ecologies. Future efforts should integrate molecular tools and multi-environment testing to enhance selection precision and cultivar stability.

This qualitative case study examines how the Communicative Language Teaching (CLT) approach can be adapted to general English classes in a higher education institution in Timor-Leste to answer the long-standing question of how students can acquire speaking proficiency in a multilingual learning environment. The paper brings into focus the incorporation of CLT into classroom activities with special emphasis on the application of role play, pair work, seminars, simulations, and task-based learning as means of promoting interactive and communicative competence. A descriptive qualitative case study design was used to develop in-depth knowledge of contextual teaching and learning experiences, the perspectives of the participants, and naturally occurring practices in the institutional setting. Semi-structured interviews, classroom observations, and document analysis were the data-gathering methods. Purposive sampling was used to select the two lecturers and seven students directly involved in teaching general English. Thematic analysis was used to analyse the data, which made it possible to identify repeated themes and patterns that revealed both opportunities and difficulties in implementing CLT in context. The results of the study indicate that, despite the adaptation of the CTL approach in teaching practices, its implementation is often sporadic due to concerns about English proficiency, teacher training, and flexibility in using local and official languages during instruction. The research demonstrates the necessity of adapting CLT methods to the local education environment and arranging long-term professional development for lecturers. This study helps us understand how context-sensitive CLT approaches can lead to improved results in teaching and learning English in Timor-Leste. The interactive approach and the systematic teacher model could significantly improve students' communicative competence.

We evaluate the correlation between polarization-dependent oxygen vacancy profile and imprint in technologically relevant TiN/La-doped Hf0.5Zr0.5O2/TiN ferroelectric capacitors using hard x-ray photoelectron spectroscopy (HAXPES) with in situ biasing. The concentration of double positively charged oxygen vacancies (VO..) was inferred from the intensity of reduced hafnium (Hf 3+, (5d1)) in the Hf 3d5/2 spectra, relative to fully oxidized (Hf 4+, (5d0)). HAXPES was performed using two photon energies to discriminate VO.. near the top interface from those averaged over the whole film. The observed time evolution of imprint and the extracted activation energy of ∼ 0.1 eV strongly indicate a fast, low-barrier electronic process such as shallow charge trapping/detrapping, rather than a slower field induced vacancy drift. On the ∼ 30 min timescale following polarization reversal, we propose that VO.. identified via HAXPES reflects a polarization-driven snapshot of the defect charge state (VOx↔VO..), rather than a change in the physical vacancy density previously reported. Following polarization reversal, electrons redistribute between vacancy levels and Hf 5d orbitals. This is correlated with Hf 4+↔ Hf 3+ transitions, leading to 0 ↔ 2+ vacancy charge state modifying the local electronic environment and screening behavior, particularly near interfaces. From the Schottky barrier height change due to polarization reversal, an effective screening length of 0.04 Å was estimated for the top interface. The results reveal a dominant role of polarization-dependent electron trapping/detrapping, partially screening ferroelectric polarization charges, thereby stabilizing one remanent state over the other.

BackgroundUrbanisation and food system transformations in low- and middle-income countries (LMICs) are reshaping local food retail environments, influencing diets and nutrition outcomes. The expansion of ultra-processed products (UPPs) and changing food outlet landscapes are key drivers of the triple burden of malnutrition across LMICs, including rising rates of obesity and related non-communicable disease (NCD). Yet, qualitative insights into how local communities interact with evolving food retail environments remains limited.MethodsA qualitative study in three urban communities of Yogyakarta, Indonesia, between September 2018 and April 2019. A total of 45 semi-structured interviews lasting between 35 min and 1.5 h were conducted with individuals primarily responsible for household food purchasing and preparation, supported by transect walks to map food outlet types. Data were analysed iteratively, combining emic perspectives with pre-determined themes based on established urban food environments and food systems frameworks.ResultsParticipants accessed a wide range of formal and informal food retail outlets. Food acquisition strategies were diverse and dynamic, with respondents often relying on multiple outlets for different product types. Five main themes emerged as key drivers of food retail outlet choice: economic reasons, convenience, produce quality, product variety, and personal or social relationships with vendors. Supermarkets were visited infrequently and mainly used for bulk or non-perishable purchases, while markets and other traditional outlets were preferred for daily needs due to perceived freshness, affordability, and trust in sellers.ConclusionFindings highlight the complexity of urban food acquisition in LMIC settings, where residents navigate diverse food retail options shaped by economic, social, and contextual factors. Informal vendors remain central to everyday food access across socio-economic groups, pointing to the need for context-specific public health policies and programmes that do not assume a linear transition toward formalisation, but instead work with existing informal structures. Interventions should aim to regulate the availability and marketing of UPPs, support healthier retail environments across all outlet types, and leverage trust, familiarity, and local networks in shaping dietary behaviours through bottom-up approaches.Supplementary InformationThe online version contains supplementary material available at 10.1186/s12889-025-23574-7.

Proton-coupled electron transfer (PCET), particularly the protonation step is widely recognized as the kinetic bottleneck in electrochemical CO2 reduction (CO2RR). Modulating catalyst microstructures to accelerate protonation has thus emerged as a promising strategy to boost from CO2 to CO selectivity. Here, we report ultrasmall Ni nanocluster catalysts (denoted as Ni3─N─C) prepared via one-step pyrolysis of Ni-containing precursors under H2 atmosphere. Compared to conventional Ni─N─C with symmetric Ni─N4 motifs, Ni3─N─C displays similar physicochemical characteristics-Ni loading, defect density, surface area-yet exhibits distinct local Ni coordination environments. These sub-nanoclusters markedly enhance CO2RR performance, delivering>90% CO Faradaic efficiency (FECO) across -0.6 to -1.0V versus RHE, with a peak FECO of ∼95% at -0.8V. Density functional theory calculations reveal that Ni3─N─C substantially lowers the energy barrier for *COOH formation owing to altered adsorption configurations, thereby facilitating the rate-limiting protonation step. In situ FTIR measurements further confirm the accelerated *COOH formation on Ni3─N─C surfaces. This work highlights the critical role of Ni sub-nanoclusters in PCET modulation and establishes a rational design principle for nanocluster-based catalysts in CO2RR.

Mycobacterium tuberculosis thrives inside macrophages by modulating intracellular pathways and adapting to various lung environments. Here, we first describe how the bacillus alters phagosome maturation, endures intracellular pressure, and obtains essential nutrients. These mechanisms have been primarily defined in cell lines and macrophage models derived from monocytes. However, recent findings regarding macrophage biology suggest that such intracellular processes might differ depending on the origin and surrounding local environment. For this reason, we then examine how different cell origins and lung niches affect infection dynamics, focusing on alveolar and interstitial macrophages, which exhibit unique metabolic and immunological characteristics. Finally, we emphasize newly identified interstitial macrophage subsets related to nerves and blood vessels, whose functions in tuberculosis are mostly unexplored but could signify potential new research opportunities. Altogether, this review highlights that a better understanding of the ontogeny and location of a macrophage is as important as comprehending its microbicidal programs in the fight against tuberculosis, by merging intracellular cellular processes with cell origin and spatial context.