Browse Articles

Synthesis, structural, and characterization of polymethylmethacrylate matrix−ZnO nanocomposite

Abstract The current work investigates the effect of incorporating zinc oxide nanoparticles (ZnO NPs) into the polymer matrix polymethylmethacrylate (PMMA), focusing on structural, thermal, mechanical, and antimicrobial properties. The synthesized polymer nanocomposites, prepared via free radical emulsion polymerization, were characterized using Fourier Transform Infrared (FTIR) spectroscopy, X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), thermal gravimetric analysis (TGA), and density measurements. Furthermore, the antibacterial and antimicrobial properties of the polymer nanocomposites were assessed against gram-negative bacteria ( E. coli ), gram-positive bacteria ( S. mutans ), and the fungus ( C. albicans ). Moreover, the mechanical characteristics, including Vickers micro-hardness, Young’s modulus, tensile strength, and elongation at break, for pure PMMA and PMMA/ZnO nanocomposite films have also been examined. The results confirm that the structure of the host matrix changes slightly upon the addition of ZnO NPs. The density measurement shows an increase, and the thermal stability is enhanced by ~ 6% for an optimum concentration of ZnO NPs addition. Additionally, the hardness number reaches its maximum value with an increase of ~ 13.5%, which is a statistically significant difference. Moreover, mechanical properties (e.g., Young’s modulus, tensile strength) and antibacterial and antimicrobial properties have shown remarkable changes. In conclusion, this work emphasizes optimal 3 wt% loading, attributed to the good dispersion of ZnO NPs, highlighting enhanced performance that can be used in denture-base applications.

Construction of waste-to-resource knowledge graph for industrial symbiosis identification using large language models

Explainable few-shot learning with modern BERT for detecting emerging phishing attacks using XF PhishBERT

Real-space machine learning of correlation density functionals

Abstract Machine learning (ML) plays a pivotal role in extending the reach of quantum chemistry methods for simulating both molecules and materials. However, leveraging ML to overcome the limitations of human-designed density functional approximations (DFAs), the primary workhorse for quantum simulations, remains a major challenge due to their severely limited transferability to unseen chemical systems. Here, we demonstrate how transferability is achieved using real-space ML, where energies are learned point by point in space through energy densities. Central to our real-space learning strategy is the derivation and implementation of correlation energy densities from regularized perturbation theory. This enables two key advances toward constructing highly transferable DFAs, grounded in the Møller-Plesset adiabatic connection framework, for correlation energies defined with respect to the Hartree-Fock reference. First, we introduce the Local Energy Loss, whose data efficiency (expanding each system’s single energy into thousands of data points) dramatically enhances transferability when combined with a physically informed ML model. Second, we formulate a real-space, machine-learned, and regularized extension of Spin-Component-Scaled second-order Møller-Plesset perturbation theory, yielding transferable DFAs that effectively mitigate the self-interaction errors common to traditional DFAs.

Mini-cutting protocol and anatomical basis of adventitious rooting in Ocotea odorifera

Frontispiece: Panchromatic Gold Alkynyl Complexes with Pyrenyl <i>‐N</i> ‐Heterocyclic Carbene Ligand Displaying Anti‐Kasha Behavior

Discovery of a Cryptic Pocket in <i>Ec</i> DsbA Opens New Opportunities for Antibacterial Discovery

Abstract We have used nuclear magnetic resonance (NMR) spectroscopy to characterize dynamics in the bacterial oxidoreductase enzyme Escherichia coli disulfide bond protein A ( Ec DsbA). Through this process we identified a cryptic pocket in the structure. We demonstrate that we can identify small molecule “fragments” that bind entirely within this cryptic site. The fragments bind to the cryptic pocket with unusually slow kinetics and a preference for interacting with the oxidized state of Ec DsbA where the two cysteine residues at the active site form a disulfide bond. We characterize the mechanism of binding, involving conformational changes in the active‐site helix of Ec DsbA, which are observed preferentially in the oxidized state. This dynamics‐driven binding mechanism explains both the slow kinetics and the redox‐dependent binding of the ligands. Furthermore, we demonstrate that compounds binding to the cryptic pocket inhibit Ec DsbA activity. These findings highlight the value of dynamics data in identification of the cryptic pocket and identify a new target site for developing more potent inhibitors of Ec DsbA.

Cationic amino acid transporters (CAT) enhance accumulation and susceptibility to the systemic herbicide L-phosphinothricin

An efficient and reproducible cryopreservation protocol for sustainable conservation of Jojoba (Simmondsia chinensis)

Abstract Simmondsia chinensis , commonly known as jojoba, is an important renewable source of liquid wax esters valued for its unique seed oil that is used in several industries. Elite jojoba germplasm needs to be conserved owing to its overexploitation, climate variability and excessive dependence of selected cultivars. This study presents a straightforward and efficient droplet vitrification-based cryopreservation protocol in jojoba. Shoot tips isolated from eight-week-old cultures were cultured for two days on high sucrose (0.3 M) enriched medium and then treated with loading solution containing 0.4 M sucrose and 2 M glycerol, followed by PVS2 exposure for 30 min at room temperature. Vitrified shoot tips were then directly frozen in liquid nitrogen by placing them on aluminium foil strips. Frozen shoot tips were rewarmed in an unloading solution containing 1.2 M sucrose for 15 min, and then cultured on regeneration medium consisting of Murashige and Skoog medium (MS) supplemented with 4.97µM benzyl-amino purine (BAP) and 0.28 µM gibberellic acid (GA 3 ). The protocol was optimized in one accession, where as high as 85.7% post-thaw survival and 76.1% regrowth were observed. The developed protocol was then tested for its efficacy and reproducibility on eleven other accession, and high post-thaw regrowth, ranging from 50 to 76.13% was observed. This study presents a broad spectrum, reproducible and efficient protocol for the conservation of jojoba genetic resources. This is the first report on cryopreservation of jojoba germplasm for its long-term conservation, providing a technical platform to set up cryobanks of valuable material of this important commercial crop.

Origin of slow earthquake statistics in low-friction soft granular shear

Abstract Slow earthquakes differ from regular earthquakes in their slower moment release and size distribution dominated by smaller events. However, the physical origin of these slow earthquake statistics remains controversial. In this work, we experimentally demonstrate that their characteristics emerge from low-friction soft granular shear. To model slow-earthquake fault materials under hydrothermal conditions, we use a low-friction soft hydrogel particle layer floating on lubricating fluid and conduct stick-slip experiments. The observed slip events follow the same laws of both moment release rate and size distribution as with slow earthquakes, contrasting with frictional rigid granular shear. Slip size is determined by the competing effects of shear localization and pressure enhancement with decreasing porosity. These findings indicate that low friction and particle softness in sheared granular systems with sparse contact structures cause slow earthquake statistics, which may be driven by pore fluid dynamics and shear localization within hazardous fault zones.

Electrospinning of core shell nanofibers using amine modified sericins

Abstract In this study as a renewable resorce, silk sericin (SS), a protein surrounding fibroin fibers in silk, was chemically modified with various amines (e.g., methylamine, butylamine) to improve its functional properties. These modifications, which included nucleophilic substitution reactions, improved its thermal stability, mechanical strength, and biological activity by substituting primary amine groups in place of hydroxyl ions in the structure. Modified SS (M-SS) was then used to produce nanofiber membranes via coaxial electrospinning. In this process, polyvinyl alcohol (PVA) served as the hydrophilic and SS/M-SS carrier polymer to delay biodegradation, while hydrophobic polylactic acid (PLA) and polycaprolactone (PCL) formed the shell to enhance mechanical strength and provide minimum adhesion to wounded tissues. This technique enabled the stable fabrication of core–shell nanofibers containing SS/M-SS, which are typically difficult to electrospin alone. Among the M-SS variants, methylamine-modified sericin (SMAT) yielded nanofibers with the highest tensile strength (0.673 MPa) and 6.44% elongation. The highest thermal resistance was observed in methylamine (SNF7) and butylamine (SNF9) modifications, with SNF7 showing 5% mass loss at 250 °C. The lowest resistance was seen in benzylamine-modified fibers (SNF11) at 220 °C. SNF9 also exhibited the highest cell viability, indicating its potential for biomedical applications.

Deciphering gene redundancy in prokaryotic genomes provides evolutionary insights for pathogenicity and its roles in clinical infections

Microencapsulation of curcumin using a fatty acid-based eutectic mixture

Abstract Curcumin (CUR), a naturally occurring polyphenol derived from turmeric, has attracted significant interest due to its wide range of therapeutic properties. However, its clinical and industrial applications are hindered by inherent challenges such as poor solubility, low stability, and limited bioavailability. To address these limitations, encapsulation techniques have been explored as a promising strategy to enhance curcumin’s stability, solubility, and bioavailability. In this study, for the first time, curcumin, as a herbal bioactive compound, was successfully microencapsulated within a bio-based phase change material (PCM). A eutectic mixture of stearic acid and lauric acid in a 1:3 molar ratio was utilized as the PCM for the microencapsulation process. The resulting microcapsules were thoroughly characterized using Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA). The findings revealed that curcumin was effectively encapsulated within the PCM, exhibiting a well-defined morphology. Furthermore, the release profile of curcumin from the microcapsules was evaluated in phosphate-buffered saline (PBS, pH 7.4) at two different temperatures (37 and 45 ○ C). The release study demonstrated a sustained and controlled release pattern, with approximately 50% and 60% of the total curcumin released at 310.15 K and 318.15 K, respectively, over a 24-hour period. These results highlight the potential of bio-based PCMs as effective carriers for the microencapsulation and controlled delivery of curcumin, offering a promising approach to enhance its therapeutic efficacy and application in drug delivery systems.

Light‐Controlled Reconfigurable Optical Structures Using Photomechanical Organic Crystals

Abstract In crystal form, 4‐fluoro‐9‐anthracenecarboxylic acid ( 4F‐9AC ) undergoes a room temperature reversible intermolecular [4 + 4] photodimerization that can be harnessed for photomechanical actuation. This negative photochromic reaction enables high conversion throughout the crystal. Patterned 405 nm excitation of single 4F‐9AC crystals creates localized photo‐dimer regions with an expansion of up to 3% of the total crystal thickness. These photoconverted regions cause reversible surface deformations and changes in birefringence that follow the reaction progress. Temperature dependent rate measurements of the photo‐dimer dissociation yield an activation energy of 97 kJ/mol, making the reversibility rate highly sensitive to temperature. By varying the crystal temperature and the light exposure level, the lifetime of the photomechanical features can be tuned from 40 milliseconds to minutes. This enables rapid updating of images and features using a commercial spatial light modulator. We use this capability to create dynamic surface relief gratings that can steer a diffracted 633 nm probe beam in arbitrary directions. The rapid mechanical response of the crystalline systems permits write–erase cycles with a duration of 1 s, which compares favorably to polymer systems.

Molecular mechanism of PINK1 regulation by the Hsp90 machinery

Using culture ‘omics to explore the microbial structure and function in an equid in vitro digestion model

Experimentally achieving minimal dissipation via thermodynamically optimal transport

Activation/inactivation of Tregs mediated by Kv1.3 potassium channels synergistically with exosome secretion to regulate myocardial fibrosis

Machine learning for risk stratification in the emergency department (MARS-ED): a randomized controlled trial

Thymosin β4 stabilizes hypoxia induced brain microvascular endothelial cell dysfunction through S1PR1 dependent mechanisms

Abstract Acute ischemic injury causes impairment of blood brain barrier (BBB) permeability and is considered as secondary insult in the brain after traumatic brain injury (TBI). The mechanisms underlying these events are incomprehensible and therefore therapeutic opportunities are limited. Although drugs have been showing some promise in TBI outcome, the restoration of BBB damage remain elusive. Thymosin β4 (Tβ4) is a secreted 43 amino acid peptide showed beneficial outcome in cerebral ischemia or TBI, however, it’s role in hypoxia-induced BBB damage remains elusive. We hypothesize that Tβ4 protect hypoxia-induced BBB disruption via Sphingosine 1–phosphate receptor 1 (S1PR1) modulation. In the current study, we investigated the beneficial effects of Tβ4 in hypoxia induced gene expression of several tight junction proteins, S1PR1, endothelial cell permeability and tight junction dynamics in human brain microvascular endothelial cells (hBMVECs), one of the important cell types in the BBB integrity. The data suggests that pretreatment with Tβ4 reversed the hypoxia-induced damage of BBB components in hBMVECs. Furthermore, results identify S1PR1, a possible target for Tβ4. Inhibition of S1PR1 showed that Tβ4 failed to offer protection. Together, data provided evidence that S1PR1 is pivotal and Tβ4 can serve as a protective agent in BBB integrity and may offer a promising therapeutic target. In conclusion, we propose that depletion of S1PR1signaling is vital in hypoxia-induced BBB pathophysiology and Tβ4 may be tested as a potential treatment modality and warrant further investigation.