Browse Articles

Thermo-mechanical effects of spiral-profiled valve guides on stress distribution and wear resistance in the valve-guide pair

A molecular timescale for evolution of cobamide biosynthesis

Cobamides are essential nutrients for most organisms but are only biosynthesized by a limited number of taxa through aerobic and anaerobic pathways. Although the origin of these widespread shared cofactors changed ecosystems and the metabolisms of living organisms, little evolutionary information is available about the biosynthetic genes and the producers. Here, we established a timeframe for the emergence of cobamide biosynthesis genes and producers, using a series of Bayesian molecular clock analyses combined with phylogenetic reconciliation. We revealed the partial producers of tetrapyrrole precursor and corrin ring were earlier than the oldest cobamide producer, suggesting the possibility that cobamide-like compounds may have existed before the emergence of their de novo producers. We also found that the anaerobic de novo producers and corrin ring producers emerged first ( Pelobacter , around 2458 Mya), and that the Great Oxidation Event postdated emergence of aerobic producers ( Kribbella , around 1784 Mya). These findings reveal the chronology of cobamide biosynthesis, which greatly changed global ecological frameworks and resulted in the current biosphere, and can guide the exploration of cross-feeding and the origin of diverse organisms on the planet.

Lightweight green composite of bacterial cellulose/tungsten oxide nanowires for attenuation of gamma radiation

Abstract Polymeric composites are recently recommended for substituting the traditional radiation shielding non-eco-friendly lead-based materials. Sustainable polymer cellulose has been studied for shielding against multiple types of radiation, but the bacterial cellulose (BC) has not received the same attention for this application although of its extraordinary physico-chemical properties such as the high crystallinity and the entangled nanofibrous structure which secure high robustness, high reactive surface area, porosity, in addition to its green footprints. Herein, we examined the potentiality of BC composites in the attenuation of gamma radiation by combining it with multiple proportions of tungsten oxide nanowires (WO 3 NWs). The synthesized WO 3 NWs underwent TEM, Zeta potential, and Zeta sizing analyses, while other structural characterization has been conducted on the BC/WO 3 NWs composites including FTIR, XRD, SEM, EDX, contact angle, TGA, where these investigations declared the compositing between the BC and WO 3 NWs. WO 3 showed their diversified sized nanowires shape under the SEM and the TEM detector, with negative surface charge (-22 mV) revealed by Zeta potential. EDX analysis of the BC/WO 3 NWs elucidated the inclusion of tungsten metal, while the contact angle analysis indicated decreased hydrophilicity degree for the BC/WO 3 NWs comparing to the pristine BC. The TGA analysis pinpointed that the BC/WO 3 NWs composite showed thermostability till T = 247 °C, before the structure start collapsing. Afterward, four BC/WO 3 NWs constructs of multiple weight percentages were tested for their gamma radiation shielding, where the examined composite exhibited an attenuation capability directly proportional to the WO 3 NWs loading whenever the photon energy was below about 250 keV. Above this photon energy, no obvious shielding impact for the BC/WO 3 NWs composite was observed, regardless of the dopant concentration. This suggests the potential of the BC/WO 3 NWs in attenuation of gamma radiation at low energy range and proposes reinforcing the composite composition to extend the scale of its shielding capacity for higher energy range.

Early warning signals for loss of control in complex systems

Maintaining stability in feedback systems, from aircraft and autonomous robots to biological and physiological systems, relies on monitoring their behavior and continuously adjusting their inputs. Incremental damage can make such control fragile. This tends to go unnoticed until a small perturbation induces instability (i.e., loss of control). Traditional methods in the field of engineering rely on accurate system models to compute a safe set of operating instructions, which become invalid when the, possibly damaged, system diverges from its model. Here we demonstrate that the approach of such a feedback system toward instability can nonetheless be monitored through dynamical indicators of resilience. This holistic system safety monitor does not rely on a system model and is based on the generic phenomenon of critical slowing down, shown to occur in the climate, biology, and other complex nonlinear systems approaching criticality. Our findings for engineered devices opens up a wide range of applications involving real-time early warning systems as well as an empirical guidance of resilient system design exploration, or “tinkering.” While we demonstrate the validity using drones, the generic nature of the underlying principles suggest that these indicators could apply across a wider class of controlled systems including reactors, aircraft, and self-driving cars.

Effects of aloe vera and silicate edible coatings on ‘Emerald’ blueberry stored at different temperatures

Pressure-induced softening of locust bean gum hydrogels: A counterintuitive alternative to freeze–thaw stiffening

Hydrogels have been widely used in biomedical and environmental applications, yet precise control of mechanical properties (quantified by elastic modulus, G′) over a broad range remains essential for expanding their functionality. While pressure treatment typically enhances hydrogel strength through pressure-induced crosslinking, we report a counterintuitive phenomenon in locust bean gum (LBG) hydrogels: High-pressure processing induces softening rather than stiffening. Under repeated compression-decompression cycles up to 1.2 GPa, LBG hydrogels undergo progressive softening, with elastic modulus decreasing to approximately 31% of the initial value. Conversely, repeated freeze–thaw cycles enhance the modulus by approximately 2.3-fold. Scanning electron microscopy reveals a structural transition from a porous network to a flocculent morphology, corresponding to substantial alterations in elastic modulus and viscoelastic behavior. Mechanistic analysis suggests that pressure-induced disruption of hydrogen bonding, water redistribution, and structural rearrangement drive these changes. These findings demonstrate that pressure modulation can serve as a complementary method to conventional freeze–thaw treatment, offering precise control over hydrogel mechanical properties across a wide range.

Influence of smoking on the human ocular surface microbiome and tear proteome

Abstract The ocular surface hosts microbes of low abundance and their genomes, collectively called the ocular surface microbiome (OSM). The OSM is involved in maintaining health and protecting the eye from infection. Although disruption of this microbial balance has been linked to various eye diseases, the effect of smoking, a known risk factor for ocular conditions, on the OSM remains unclear. We analysed ocular samples from smokers ( n  = 17) and non-smokers ( n  = 24) using metagenomic sequencing and proteomics approaches to assess both microbial composition and functions, as well as the host protein profiles. Microbial DNA was examined for bacterial, fungal, and viral taxa, with contaminants removed using microDecon. Statistical analyses showed no significant differences in microbial diversity or tear proteins between groups, apart from one bacterial gene. No bacterial, fungal, or viral species were uniquely associated with smoking status. While no clear smoking-related effects were observed in microbial communities or tear proteome composition, the overall stability of tear proteins may reflect intrinsic resilience dynamics that maintain low microbial abundance on the ocular surface.

Correlating picosecond electron transfer and confined water dynamics in Prussian Blue using electrochemical two-dimensional infrared spectroscopy

Prussian Blue is not only the oldest synthetic pigment, but also an electrochemically active material with modern technological relevance for its electrochromic properties and applications in energy storage. In this work, we study the fundamental mechanism of electron transport processes in this material, and how it varies as the material is progressively oxidized from Prussian White to Prussian Blue. Recently developed methods in spectroelectrochemical ultrafast 2D infrared spectroscopy allow us to measure the electron transfer rate within a film of Prussian Blue deposited onto the working electrode in an electrochemical cell as a function of applied bias potential. The intrinsic CN stretching modes serve as a local probe of the Fe oxidation state and as a measure for the solvation dynamics induced by water molecules incorporated into the subcells of the zeolitic lattice. We observe a fast, ps-scale electron transfer process with a rate that varies with the state of the material, revealing the intrinsic mobility of electrons decoupled from the slow diffusion of K+ ions. By correlating these observations to changes in the local structural distributions of FeIII sites, K+ ions and water molecules with the aid of a lattice model, we obtain insight into the mechanism of electron transport in this material. These results demonstrate a method for observing fast electron transfer and correlating them with nuclear motions, and provide a way to study chemical transformations at the electrochemical interface.

Psychosomatic Susceptibility Profile (PSSP): a machine-learning-derived eight-item instrument integrating personality and coping for psychosomatic risk stratification

Abstract Psychological, behavioral, and physical factors jointly contribute to heterogeneity in health-related outcomes, yet existing instruments often assess these domains separately or require lengthy questionnaires. In this study, we aimed to identify multidimensional psychosomatic profiles and develop a brief machine learning–based tool for their classification. Data from 3,207 employees (aged 18–65 years) were analyzed using responses from the NEO Five-Factor Inventory (NEO-FFI), coping questionnaires, the 12-item General Health Questionnaire (GHQ-12), body mass index (BMI), and physical activity measures. To enable integrated analysis, questionnaire responses were transformed into text-based representations and encoded using DistilBERT embeddings, followed by dimensionality reduction using principal component analysis. Spectral clustering identified latent psychosomatic profiles, resulting in three distinct subgroups characterized by different psychological, behavioral, and physical patterns. A supervised machine learning model was then trained to classify profile membership, and SHAP-based feature selection identified a minimal subset of informative items. This process yielded an eight-item instrument, the Psychosomatic Susceptibility Profile (PSSP), consisting of selected personality and coping items. An XGBoost classifier with five-fold cross-validation demonstrated good internal performance (F1 = 0.80; recall = 0.81). Overall, this study presents a data-driven framework for identifying multidimensional psychosomatic profiles and deriving a brief, interpretable classification tool for efficient profile assignment in research and applied settings.

Intrabubble coupled evolution of microdroplets and nanobubbles in oxygen evolution reaction

In the oxygen evolution reaction (OER), adherent gas bubbles are conventionally viewed as a major impediment that blocks ion and mass transport by covering active sites. Here, we show that for ionomer-based electrodes, this prevailing view is oversimplified. Using a self-developed transparent on-chip electrolyzer that integrates multimodal in-situ characterization, including optical microscopy, spectroscopic analysis, and atomic force microscopy, we uncover complex intrabubble dynamics on ionomer-coated electrodes. During bubble growth, the three-phase contact line exhibits characteristic pinning–depinning behavior. Beyond a critical bubble size (~420 μm), free water molecules are evolved from the ionomer into the bubble–electrode contact area, forming microdroplets (<20 μm) that continuously coalesce. Inside these microdroplets, oxygen products further nucleate as pancake-shaped nanobubbles (~50 nm), revealing a previously unrecognized intrabubble process. We find that this coupled microdroplet–nanobubble evolution is enabled by the phase-separation behavior of ionomer. The ionomer also preserves local electrochemical activity even under substantial bubble coverage, unlike ionomer-free electrodes where bubble blockage leads to severe deactivation. By tailoring ionomer phase separation, we achieve intensified microdroplet–nanobubble evolution and measurable performance improvement at high current densities. This finding opens a route to mitigate bubble-induced activity loss in OER electrodes.

Multi-objective optimization approach for energy efficient clustering and routing in wireless sensor networks

A human lysosomal storage disorder toolkit for decoding proteome landscapes in cortical-like and dopaminergic-like induced neurons

Lysosomes maintain cellular homeostasis by degrading proteins delivered via endocytosis and autophagy and by recycling building blocks for organelle biogenesis. Lysosomal storage disorders (LSDs) comprise a group of diseases affecting diverse lysosomal functions. To facilitate molecular phenotyping across diverse LSD gene classes, we are developing a library of human embryonic stem cells engineered to lack individual LSD genes as a resource for the field. Here, we report our initial stem cell toolkit lacking one of 23 LSD genes, including the majority of genes associated with sphingolipidoses and neuronal ceroid lipofuscinoses, and its use in the generation of a proteomic resource for induced cortical-like and midbrain dopaminergic-like neurons. In-depth abundance and correlation profiling across organelles and suborganelle components revealed potential vulnerabilities that reflect distinct patterns of proteome alterations across both genotypes and neuronal cell types. We characterize alterations in the mitochondrial proteome associated with GBA1 and ASAH1 deficiency and identify synaptic and mitochondrial defects in ASAH1 −/− induced neurons that correlate with defects in neuronal firing rates. Moreover, we developed an informatic pipeline for proteome-wide identification of individual protein-protein interactions and protein complexes that may be disrupted as a result of LSD gene deficiency. Finally, we visualized structural alterations of ASAH1 -deficient endolysosomes in situ using cryoelectron tomography, revealing swollen organelles that were largely devoid of dense internal membranes characteristic of wild-type cells, but containing numerous intralumenal vesicle compartments. This toolkit and associated proteomic landscapes provide a resource for defining molecular signatures associated with LSD gene dysfunction and organelle vulnerability.

Fractional thermodynamics resolves the Stokes–Einstein breakdown in supercooled water

Coordination of N ₂ -fixing cell specialization and patterning in filamentous cyanobacteria by a uniquely structured σ factor

Cell differentiation and Turing-like patterning are tightly associated in a group of filamentous cyanobacteria that differentiate specialized N 2 -fixing cells, called heterocysts. Based on systematic genetic analyses, in particular genome-wide identification of recognized promoters and assays with a reconstituted Anabaena transcription system in Escherichia coli , we established HetZ as the central activator of the gene regulatory network of heterocyst differentiation. Biochemical and cryo-EM analyses further established HetZ as a σ factor (σ HetZ ). Unique domain insertions in σ HetZ are involved in promoter DNA recognition-unwinding and interaction with the inhibitor PatU3. σ HetZ -PatU3 and the master regulator-diffusible inhibitor constitute the minimal core regulatory circuit (CRC) for cell fate determination and patterning. σ HetZ activates not only genes of the CRC but also downstream regulator/effector genes involved in morphological and functional development. The gene regulatory network and the structure–function relationship of σ HetZ depict how cell differentiation and patterning are coordinated in this group of multicellular cyanobacteria.

Network pharmacology and in silico analysis of Azadirachta indica phytoconstituents reveal potential hepatoprotective targets and mechanisms

A systems-level atlas of carbon-response transcriptional states in <i>Escherichia coli</i>

Escherichia coli encounters chemically diverse carbon sources, and the observed outputs of its transcriptional regulatory network (TRN) vary with substrate chemistry, metabolic entry route, and growth physiology. Here, we compiled PRECISE-NP881, an 881-condition transcriptome compendium comprising 346 RNA-seq profiles generated for this study during growth on 43 individual carbon sources, and used independent component analysis to quantify condition-specific activities of 137 iModulons, defined here as statistically independent gene-expression modules. We identified 25 carbon-catabolism iModulons and summarized their activity patterns across the 43 substrates into four activity-defined substrate groups. These activity patterns were associated with measured growth rates, substrate chemical classes, central-metabolic entry routes, carbon-normalized stoichiometric yield, and model-estimated proteome allocation. Faster-growing sugar conditions showed low CRP-linked iModulon activity, whereas slower-growing conditions showed elevated, condition-specific activity of CRP-linked and substrate-specific catabolic iModulons. TCA-entry and amino acid–associated conditions were linked with NtrC-1 and Propionate iModulon activities, with targeted knock-out assays supporting the conditional physiological relevance of selected propionyl-CoA-associated genes. A subset of nitrogen-containing, slower-growth conditions with predicted ammonium release induced the cryptic prophage-associated SgcABCEQX iModulon. Projection of an independent glucose starvation/refeeding time-course dataset revealed overlapping dynamics among selected carbon-catabolism iModulons and coordinated changes in growth- and stress-associated TRN outputs. Together, these results provide a systems-level atlas of observed carbon-responsive transcriptional states and systematize carbon physiology at scale.

Lack of association between APOE genotypes and COVID‐19 in a black South African cohort

Measurement of isotope fractionation associated with crystal nucleation: Implications for biocrystallization studies

Isotopic fractionation is a unique indicator of the mechanisms of mineral precipitation from aqueous solutions, but existing theory does not account for nucleation effects or nonclassical growth mechanisms. Here, using barite (BaSO 4 ) as a model crystal, we provide an experimental measurement of isotope fractionation associated with nucleation. We isolated nucleation effects by precipitating crystals on an organic film, where cation enrichment creates a highly supersaturated microenvironment so nucleation dominates over crystal growth. In a single batch experiment, we retrieved nanocrystals (~1.5 nm) from the organic substrate and large microcrystals in bulk solution where growth dominates. The 138 Ba/ 134 Ba isotopic fractionation of −0.6 to −0.8‰ for the microcrystals match those expected for classical ion-by-ion growth from a moderately supersaturated solution, whereas the fractionation for the nucleation-dominated nanocrystals is about −0.1‰, falling within the reported equilibrium fractionation range between barite and aqueous Ba 2+ . These results demonstrate that cation isotopic fractionation in sparingly soluble salts like barite and calcite is not a single-valued function of saturation indices (SI) and precipitation rate as predicted with current theory, with the fractionation factor (∆ 138/134 Ba barite-soln = δ 138/134 Ba barite − δ 138/134 Ba solution ) increasing in magnitude with increasing SI. Instead, the shifting precipitation mechanism(s) at high SI cause the fractionation factor to return to near-equilibrium values. This finding may be critical for understanding isotopic fractionation in localized extreme environments in nature, including for Ba isotopes during biomineralization.

SAW YOLO lightweight network for fire hazard detection in ancient wooden structures

A genome-wide screen identifies that PLCG2 restrains lysosomal GCase activity

Mutations in the GBA1 gene, which encodes the lysosomal glucocerebrosidase enzyme GCase, cause the lysosomal storage disorder Gaucher disease and represent the most common genetic risk factor for Parkinson’s disease (PD). These mutations deplete lysosomal GCase activity and cause accumulation of GCase substrate, glucosylceramide, and its pathological metabolite, glucosylsphingosine. Impaired GCase activity then drives immune and neuronal dysfunction in Gaucher disease and promotes pathogenic aggregation of α-Synuclein in PD. As such, boosting the lysosomal activity of GCase is a therapeutic strategy to ameliorate substrate accumulation and prevent associated neurotoxicity. To identify the regulators of GCase activity in lysosomes, we conducted a genome-wide screen in primary mouse macrophages using a fluorescent enzyme activity reporter. By validating the screen hits in cellular biochemical and profiling assays, we identified pathways that promote or inhibit lysosomal GCase activity. Our screen identified PLCG2 as a regulator of lysosomal GCase activity. Mechanistically, PLCG2 depletion accumulates Golgi-associated phosphatidylinositols, promoting the transport of mutant GCase into lysosomes while reducing its Golgi-associated pool. Functionally, PLCG2 depletion boosts the activity of lysosomal mutant GCase, the cellular flux of glucosylceramide, and the clearance of pathogenic GCase substrates. In summary, our screen has uncovered the regulators of GCase abundance and trafficking at a whole-genome scale and identified potential pathways for future therapeutic interventions in Gaucher and Parkinson’s to boost the activity of this enzyme in lysosomes.