Browse Articles

Apical size reduction by macropinocytosis alleviates tissue crowding

Abstract Tissue crowding represents a critical challenge to epithelial tissues, which often respond via the irreversible process of live cell extrusion. We report that apical size reduction via macropinocytosis serves as a malleable and less destructive form of tissue remodeling that can alleviate the need for cell loss. We find that macropinocytosis is triggered by tissue crowding via mechanosensory signaling, leading to substantial internalization of apical membrane. This drives a reduction in apical surface which alleviates crowding. We report that this mechanism regulates the long-term organization of the developing epithelium and controls the timing of proliferation-induced cell extrusion. Additionally, we observe a wave of macropinocytosis in response to acute external compression. In both scenarios, inhibiting macropinocytosis induces a dramatic increase in cell extrusion suggesting cooperation between cell extrusion and macropinocytosis in response to both developmental and external compression. Our findings implicate macropinocytosis as an important regulator of dynamic epithelial remodeling.

Age-related variations in trunk muscle activation and kinematics during lifting in chronic low back pain: a cross-sectional study

Abstract Chronic low back pain (cLBP) is a leading cause of disability worldwide, however, the influence of age on electromyography (EMG) during lifting tasks is not well understood. This study examined the effects of age and pain on EMG and kinematics in 102 participants. They were divided into no low back pain (no-BP) (n = 42; mean age: 41.86) and cLBP groups (n = 60; mean age: 43.41) and further categorized by age: 44 under 40 years (mean age: 31.14) and 58 over 40 years (mean age: 51.38). Two lifting tasks from the ground to the hip height were performed: lifting a 10 kg box in front of the body (Task 1) and two 5 kg dumbbells beside the body (Task 2), with EMG and flexion angles recorded. Older participants showed significantly higher EMG amplitudes (p < 0.05), particularly in Task 1 while holding the weight at hip height. No significant EMG differences were found between cLBP and no-BP groups after adjusting for age, sex, and body mass index (BMI) (p > 0.05). Task 1 showed higher back muscle activation than Task 2 (p < 0.05). These findings suggest that age, rather than pain, may play a more critical role in muscle activation, highlighting the need for age-specific interventions in cLBP rehabilitation.

Author Correction: SENP1-mediated NEMO deSUMOylation in adipocytes limits inflammatory responses and type-1 diabetes progression

A novel metaheuristic optimizer GPSed via artificial intelligence for reliable economic dispatch

Abstract Recently, meta-heuristic optimization algorithms have enhanced resource efficiency, facilitated informed decision-making, and addressed complex problems involving multiple variables and constraints in engineering and science fields. However, numerous handicaps are reported on the performance of a quite number of these optimizers, such as local solution trapping, slow convergence and the requirements for elevated storage and computation capability. This article proposes a novel, simple, and elaborate remedy for the reported deficiencies of meta-heuristic optimizers. This deficiency is accomplished by proposing a hybrid optimizer composed of an ambiguous optimizer and Artificial Intelligence (AI). The performance of the proposed technique is evaluated using four different meta-heuristic optimizers: Genetic Algorithm (GA), Particle Swarm Optimization (PSO), Teaching–Learning-Based Optimization (TLBO), and Artificial Gorilla Troops Optimization (AGTO). These optimizers range from the mature to the recently evolved. These meta-heuristic optimizers validate the proposed solver and confirm its applicability to any meta-heuristic optimization algorithm. Economic Dispatch (ED) of the IEEE 30-bus system is utilized to evaluate the performance of the proposed solver. The comprehensive results demonstrate the superiority, reliability, and adequacy of the proposed technique. It consistently converges to the global optimum solution, achieving the minimum energy cost of the system under concern while requiring the fewest iterations and minimal computational requirements.

Author Correction: Detection of single-mode thermal microwave photons using an underdamped Josephson junction

Morphological, vascular, and functional changes in macular telangiectasia type 2 in Egyptian patients

Abstract Little documented studies regarding analysis of macular telangiectasia type 2 in Egyptian patients. This prospective study included 24 eyes with MacTel-2, and 24 control eyes. Spectral-domain optical coherence tomography Angiography (OCT-A) was performed. Staging of eyes with MacTel-2, quantification of Foveal and parafoveal vascular density and full retinal thickness were performed. In MacTel-2 eyes, the superficial capillary vessel density was significantly decreased in the temporal, superior and inferior para-foveal area (p-value = 0.004, < 0.001 and 0.002 respectively). Only temporal parafoveal deep vessel density showed significant decrease in the MacTel-2 group as compared with the normal control group (49.6% versus 54.01%, p value = 0.010). There was a statistically significant decrease in the foveal and all the para-foveal thickness as compared with normal control group (P < 0.001). One-fourth of cases were classified as stage 4 MacTel-2. The patterns of neovessels were sea-fan, tangled or dead tree network, equally distributed among the six affected eyes. A significant reduction in both foveal density and visual acuity was documented with disease progression. This study emphasizes the role of OCT-A in diagnosis, staging and identification of neovascular pattern of MacTel-2. Furethermore, this study is considered one of the few Egyptian studies in staging the disease providing correlation to visual acuity, macular thickness and vessel density affection.

Obesity drugs show promise for treating a new ailment: migraine

Author Correction: Membrane adsorbers with ultrahigh metal-organic framework loading for high flux separations

Eco-friendly spectrofluorimetric determination of remdesivir in the presence of its metabolite in human plasma for therapeutic monitoring in COVID-19 patients

Abstract The global outbreak of the novel coronavirus (COVID-19) has highlighted the urgent need for innovative therapeutic solutions. Remdesivir (REM) was the first drug granted approval by the US FDA for treating hospitalized COVID-19 patients. A selective and sensitive derivative spectrofluorimetric method has been developed and validated for the determination of Remdesivir (REM) in presence of its Alkaline-induced degradation product (AKDP), which is also known to be its metabolite (GS-441524). The method utilized the intrinsic fluorescence properties of REM, achieving a linear response within the range of 3.0–120.0 ng/mL at 428.3 nm using first-order derivative. Methodological parameters were optimized to ensure high sensitivity, with detection and quantification limits of 1.12 and 3.67 ng/mL, respectively. This approach successfully quantified REM in pure form, intravenous infusions, and spiked human plasma. Recovery rates in plasma were satisfactory at 97.64 ± 1.87, confirming the method’s suitability for therapeutic drug monitoring (TDM) in COVID-19 patients. Additionally, the environmental sustainability of the method was evaluated using GAPI, AGREE, and RGB12 metrics, underscoring its green and eco-friendly characteristics.

Smart and solvent-switchable graphene-based membrane for graded molecular sieving

Growth performance, carcass traits, and histological changes of goats supplemented with different sources of phytochemicals

Abstract Phytogenic feed additives are increasingly used to improve animal health and productivity. This study compared the effect of supplementation with tannin to an herbal mixture consisting of ginger, garlic, artemisia, and turmeric on the performance, intestinal parasites, blood metabolites, carcass characteristics, and histology of muscles and intestine of goats. Twenty-seven Shami male goats were assigned to three treatments (n = 9): non-supplemented goats fed a control diet (CC); goats supplemented with 10g /animal/day of quebracho tannins as a source of condensed tannin (TT); and goats supplemented with 10g/animal/day of an herbal mixture (HM). All the animals received a basal diet consisted of concentrate feed mixture and alfalfa hay. The supplementation improved growth performance, nutrients digestibility, and serum immunoglobulins concentration (P < 0.05). The supplementation decreased fecal parasite counts, blood cholesterol, and glutamic-pyruvic transaminase (GPT) enzyme and improved blood glucose (P < 0.05). The supplementation decreased renal and meat fat, and group HM revealed higher polyunsaturated fatty acids and α-Linolenic acid in meat (P < 0.05). Tannin supplementation (TT group) negatively affected the histology of muscles and intestines. The results provide evidence for the beneficial use of an herbal mixture in the diet to improve animal performance, health status, and meat quality in goats.

Author Correction: MiR-497∼195 cluster regulates angiogenesis during coupling with osteogenesis by maintaining endothelial Notch and HIF-1α activity

Cholinergic basal forebrain neurons regulate vascular dynamics and cerebrospinal fluid flux

Abstract Brain waste is cleared via a cerebrospinal fluid (CSF) pathway, the glymphatic system, whose dysfunction may underlie many brain conditions. Previous studies show coherent vascular oscillation, measured by blood oxygenation level-dependent (BOLD) fMRI, couples with CSF inflow to drive fluid flux. Yet, how this coupling is regulated, whether it mediates waste clearance, and why it is impaired remain unclear. Here we demonstrate that cholinergic neurons modulate BOLD-CSF coupling and glymphatic function. We find BOLD-CSF coupling correlates cortical cholinergic activity in aged humans. Lesioning basal forebrain cholinergic neurons in female mice impairs glymphatic efflux and associated changes in BOLD-CSF coupling, arterial pulsation and glymphatic influx. An acetylcholinesterase inhibitor alters these dynamics, primarily through peripheral mechanisms. Our results suggest cholinergic loss impairs glymphatic function by a neurovascular mechanism, potentially contributing to pathological waste accumulation. This may provide a basis for developing diagnostics and treatments for glymphatic dysfunction.

Author Correction: Biogel scavenging slows the sinking of organic particles to the ocean depths

Observing nucleation and crystallization of rock salt LiF from molten state through molecular dynamics simulations with refined machine-learned force field

Lithium fluoride is a critical component for stabilizing lithium metal anodes and high-voltage cathodes toward the next-generation high-energy-density lithium batteries. A recent modeling study reported the formation of wurtzite LiF below ∼550 K (Hu et al., J. Am. Chem. Soc. 2023, 145, 1327–1333), in contrast to the experimental observation of rock salt LiF under ambient conditions. To address this discrepancy, we employ molecular dynamics simulations with a refined machine-learned force field (MLFF) and demonstrate the nucleation and crystallization of rock salt LiF from the molten phase at temperatures below ∼800 K. The rock salt phase remains stable in LiF nanoparticles. Complementary density functional theory calculations show that dispersion interactions are essential for correctly predicting the thermodynamic stability of rock salt LiF over the wurtzite phase on top of the commonly used PBE functional. Furthermore, we show that inclusion of virial stresses, alongside energies and forces, in the training of MLFFs is crucial for capturing phase nucleation and crystallization of rock salt LiF under the isothermal–isobaric ensemble. These findings underscore the critical role of dispersion interactions in atomistic simulations of battery materials, where such effects are often non-negligible, and highlight the necessity of incorporating virial stresses during the training of MLFFs to enable accurate modeling of solid-state systems.

Tunable layer-specific polarizability in twisted multilayer graphene flakes capped with hexagonal boron nitride

Twisted multilayer graphene (TMG) capped with hexagonal boron nitride (hBN) exhibits distinctive electronic phenomena under a vertical electric field. However, the dielectric constant alone is insufficient to comprehensively characterize the dielectric properties of low-dimensional materials, posing challenges for accurately measuring and controlling their field response. To address this, we develop a site-specific polarizability decomposition approach based on first-principles calculations, enabling the separation of intra- and interlayer polarizabilities in TMG@hBN. This method is applied to 2580 constructed configurations of TMG flakes with and without hBN encapsulation. Our findings reveal that intralayer polarizability dominates the overall magnitude, while the interlayer component governs its variation with twist angle. hBN encapsulation enhances interlayer polarizability while reducing its twist-angle dependence. For both TMG and TMG@hBN, the inner graphene layers exhibit negligible γ, which quantifies the layer-specific interlayer charge transfer response to an external field, while significant γ values emerge in the outermost graphene layers (γGra) and hBN (γBN). Interestingly, γGra and γBN exhibit opposite signs in non-equivalent layers, and γGra reverses between pristine TMG and TMG@hBN. Compared to TMG, γGra in TMG@hBN is suppressed, with variations strongly dependent on thickness, twist angle, and stacking patterns, particularly when nitrogen atoms align over phenyl ring centers. In addition to the well-known Bernal-stacked structure, notable changes in interlayer polarizability and γGra are also observed in slightly misaligned (AA)N-stacked structures with the exceptional twist angle (θp). This scalable method enables layer-resolved analysis of intra- and interlayer contributions, offering new insights for tuning electric field responses and optimizing graphene-based optoelectronic devices.

Revealing the importance of the C(1) position to modulate the photophysics and Z-scan responses of <i>o</i>-locked GFP chromophores

Three novel ortho-locked (o-locked) green fluorescent protein (GFP) chromophores, which are also doubly locked, with a phenyl group at the C(1) of the imidazolinone ring and substituents with varying electronic effects at the C(9) of the benzylidene moiety, have been synthesized. All the chromophores show relatively weak but much red-shifted emissions compared to their methyl counterparts at C(1), as previously reported by us [D. Paul et al., J. Phys. Chem. B 129, 692–711 (2025)]. Quantum chemical calculations indicate that the excited state dynamics of the chromophores possess initial rotation of the phenyl, followed by proton transfer and geometry twisting. Fluorescence decays confirm an early time charge transfer from the benzylidene moiety to the electron-withdrawing substituents at C(9). The relaxation processes occur within a time range of hundreds of femtoseconds to a few picoseconds, subject to respective compounds. This study supports our earlier reported findings [D. Paul et al., J. Phys. Chem. B 129, 692–711 (2025)] that the electronic effect at C(9) significantly affects the quantum yields of o-locked GFP chromophore analogs. This study also shows that solvent viscosity and temperature play dominant roles in modulating the fluorescence intensities of o-locked GFP chromophores. Furthermore, these compounds display significantly superior nonlinear optical (NLO) properties than their methyl analogs [D. Paul et al., J. Phys. Chem. B 129, 692–711 (2025)]. These findings provide valuable insight regarding the correlation between the molecular structures of o-locked GFP chromophores and their spectroscopic nature and pave the way to structurally engineering improved fluorophores. In a nutshell, these chromophores with a phenyl group at C(1), with poor but highly red-shifted emission in solution, showing viscosity dependency on emission intensity, and high NLO properties, can be very useful in bio-imaging.

Formally exact fluorescence spectroscopy simulations for mesoscale molecular aggregates with <i>N</i>0 scaling

We present a size-invariant (i.e., N0) scaling algorithm for simulating fluorescence spectroscopy in large molecular aggregates. We combine the dyadic adaptive hierarchy of pure states (DadHOPS) equation-of-motion with an operator decomposition scheme and an efficient Monte Carlo sampling algorithm to enable a formally exact, local description of the fluorescence spectrum in large molecular aggregates. Furthermore, we demonstrate that the ensemble average inverse participation ratio of DadHOPS wave functions reproduces the delocalization extent extracted from fluorescence spectroscopy of J-aggregates with strong vibronic transitions. This work provides a computationally efficient framework for fluorescence simulations, offering a new tool for understanding the optical properties of mesoscale molecular systems.

Machine learning short-ranged many-body interactions in colloidal systems using descriptors based on Voronoi cells

Machine learning (ML) strategies are opening the door to faster computer simulations, allowing us to simulate more realistic colloidal systems. Since the interactions in colloidal systems are often highly many-body, stemming from, e.g., depletion and steric interactions, one of the challenges for these algorithms is capturing the many-body nature of these interactions. In this paper, we introduce a new ML-based strategy for fitting many-body interactions in colloidal systems where the many-body interaction is highly local. To this end, we develop Voronoi-based descriptors for capturing the local environment and fit the effective potential using a simple neural network. To test this algorithm, we consider a simple two-dimensional model for a colloid-polymer mixture, where the colloid–colloid interactions and colloid–polymer interactions are hard-disk like, while the polymers themselves interact as ideal gas particles. We find that a Voronoi-based description is sufficient to accurately capture the many-body nature of this system. Moreover, we find that the Pearson correlation function alone is insufficient to determine the predictive power of the network emphasizing the importance of additional metrics when assessing the quality of ML-based potentials.

Soft x-ray spectroscopy of ammonium sulfate aerosols at varied pH conditions

Aqueous aerosols are useful model systems for understanding the physical chemistry that takes place in the Earth’s atmosphere, as well as the chemistry of other solar system objects. Ammonium sulfate aerosols are impacted by anthropogenic sources such as farming and shipping and are understood to be important seeds of cloud nucleation in the atmosphere, affecting climate. X-ray photoelectron spectroscopy and near edge x-ray absorption fine structure spectroscopy were used in tandem to probe the surface and bulk properties of aqueous (NH4)2SO4, respectively. Aerosolized solutions of (NH4)2SO4, some altered with NaOH to modify pH, were introduced via an aerodynamic lens to a velocity map imaging instrument for detection. The results show that as pH and sodium cation concentration increase, sulfate anion and ammonia become more prevalent at the surface, and the aerosol surface appears to become drier. However, most of the aerosol remains aqueous, with ion concentrations insensitive to the addition of NaOH. Density functional theory calculations were also performed to probe the coordination environment at the aerosol surfaces to understand the underlying phenomena. The changes seen on the surface of the aerosol underscore the importance of pH in regulating the structure and chemical properties of atmospherically relevant aerosols.