Search Results (1,072)

Most sweet cherry varieties exhibit typical gametophytic self-incompatibility (GSI) characteristics, necessitating careful configuration of pollination trees to ensure adequate yields. This requirement increases the costs associated with orchard labor, management, and other related expenses. Consequently, cultivating and developing sweet cherry cultivars with self-compatibility can effectively address these challenges. Research into the molecular mechanisms underlying GSI formation can provide vital theoretical support and genetic resources for breeding self-compatible sweet cherries. In this study, we assessed the fruit set rates of ‘Tieton’ following both self- and cross-pollination. Additionally, we conducted a transcriptome analysis of the ‘Tieton’ style (which includes the stigma) at 0, 12, 24, and 48 h post-pollination to identify key genes involved in the self-incompatibility process of sweet cherries. The results indicated that the self-fruiting rate of ‘Tieton’ was significantly lower than that of cross-pollination. We identified a total of 8148 differentially expressed genes (DEGs) through transcriptome analysis, with KEGG pathway analysis revealing that the plant-pathogen interaction, plant hormone signal transduction, and plant MAPK signaling pathways were primarily involved in sweet cherry GSI. Furthermore, we identified 13 core transcription factors (TFs) based on their differential expression patterns, including three ERFs, three NACs, three WRKYs, two HD-ZIPs, one RAV, and one MYB. Co-expression analysis identified 132 core DEGs significantly associated with these TFs. Ultimately, this study provides initial insights into the key genes within the sweet cherry GSI network, laying a theoretical foundation and offering genetic resources for the future molecular design breeding of new self-compatible varieties. Full article

Polymer flooding is an enhanced oil recovery (EOR) technique that improves oil extraction by injecting polymer solutions into reservoirs. However, the disposal and treatment of polymer flooding waste liquids (PFWL) present significant challenges due to their high viscosity, complex molecular structure, and environmental impact. This study investigates the shear-induced degradation of polymer solutions, focusing on rheological properties, particle size distribution, and morphological changes under controlled shear conditions. Experimental results show that shear forces significantly reduce the viscosity of polymer solutions, with shear rates of 4285.36 s⁻¹ in the rotating domain and 3505.21 s⁻¹ in the fixed domain. The particle size analysis reveals a significant reduction in average particle size, indicating polymer aggregate breakup. SEM images confirm these morphological changes. Additionally, numerical simulations using a power-law model highlight the correlation between shear rate, wall shear stress, and polymer degradation efficiency. This study suggests that optimizing rotor–stator configurations with high shear forces is essential for efficient polymer degradation, offering insights for designing more effective polymer waste liquid treatment systems in oilfields. Full article

Dielectric crystals with switchable electric polarizations represent the key functional materials utilized for a broad range of practical applications. They allow for academically intriguing platforms, where the use of a strong external electric field can potentially unveil hidden crystal phases. Proton–π-electron correlated bistable systems turn out to be promising for exploring such electrically induced crystal polymorphisms, mainly because strong π-electronic polarization can be sensitively switched depending on mobile hydrogen locations. Pseudo-symmetry and hydrogen disorder are utilized as clues for the data mining of the Cambridge Structural Database in the search for molecular candidates with novel switchable dielectrics. The polarization hysteresis, electrostriction, and second harmonic generation of the candidates were experimentally evaluated, together with the re-inspection of crystal structure. This feature article highlights the rich variation and competition of some candidate polarization configurations and switching modes in close relation to high and efficient electrical energy storage/discharge, large electrostriction effects, polarization rotations, and multistage switching phenomena. The experimental findings are well-reproduced by the computational optimization of crystal structure and the simulation of the switchable polarization, piezoelectric coefficients, and relative stability for each of the real or hypothetical hydrogen-ordered crystal phases. Effective prediction and strategic design are thereby guaranteed by systematically understanding the appropriate integration of experimental, computational, and data sciences. Full article

While calcium (Ca²⁺) is a universal cellular messenger, the ionic properties of magnesium (Mg²⁺) make it less suited for rapid signaling and more for structural integrity. Still, besides being a passive player, Mg²⁺ is the only active Ca²⁺ antagonist, essential for tuning the efficacy of Ca²⁺-dependent cardiac excitation–contraction coupling (ECC) and for ensuring cardiac function robustness and stability. This review aims to provide a comprehensive framework to link the structural and molecular mechanisms of Mg²⁺/Ca²⁺ antagonistic binding across key proteins of the cardiac ECC machinery to their physiopathological relevance. The pervasive “dampening” effect of Mg²⁺ on ECC activity is exerted across various players and mechanisms, and lies in the ions’ physiological competition for multiple, flexible binding protein motifs across multiple compartments. Mg²⁺ profoundly modulates the cardiac action potential waveform by inhibiting the L-type Ca²⁺ channel Cav1.2, i.e., the key trigger of cardiac ryanodine receptor (RyR2) opening. Cytosolic Mg²⁺ favors RyR2 closed or inactive conformations not only through physical binding at specific sites, but also indirectly through modulation of RyR2 phosphorylation by Camk2d and PKA. RyR2 is also potently inhibited by luminal Mg²⁺, a vital mechanism in the cardiac setting for preventing excessive Ca²⁺ release during diastole. This mechanism, able to distinguish between Ca²⁺ and Mg²⁺, is mediated by luminal partners Calsequestrin 2 (CASQ2) and Triadin (TRDN). In addition, Mg²⁺ favors a rearrangement of the RyR2 cluster configuration that is associated with lower Ca²⁺ spark frequencies. Full article

This study explores the physicochemical and toxicological properties of six G-series and A-series chemical warfare agents (Sarin, Soman, Tabun, A230, A232, and A234) using an integrated computational approach combining molecular dynamics (MD) simulations and Quantitative Structure–Activity Relationship (QSAR) modeling. For the A-series nerve agents, both Ellison–Hoenig and Mirzayanov structural proposals were examined. MD simulations (10 ns, NPT ensemble) provided key thermodynamic properties, including density, molar heat capacity, and diffusivity. Simulated densities for G-agents (e.g., Sarin: 1.09 g/cm³, Soman: 1.03 g/cm³) and A-agents (e.g., A230: 1.608 g/cm³, Ellison–Hoenig model) closely matched experimental data. Heat capacities ranged from 258 to 462 J/mol·K, and self-diffusion coefficients revealed lower mobility for A-agents, especially under the Ellison–Hoenig configurations. QSAR modeling focused on lipophilicity (LogP) and acute toxicity (LD₅₀). Predicted LD₅₀ values ranged from 0.012 to 0.017 mg/kg for G-agents and up to 1.23 mg/kg for A-agents. A-234 showed the highest lipophilicity (LogP = 2.97) and toxicity (LD₅₀ = 0.51 mg/kg) within its group. Additional descriptors, such as molecular weight and polar surface area, supported toxicity predictions. Strong correlations emerged between MD-derived properties and QSAR outputs, validating the integrated approach. The combined use of MD and QSAR techniques provided a comprehensive view of the agents’ environmental behavior and toxicological impact, supporting safer assessment strategies and reinforcing the importance of multidisciplinary modeling for chemical threat mitigation. Full article

The growing demand for effective water treatment solutions, particularly in smaller communities in Brazil, highlights the potential of ozonation. However, implementing this technology at a smaller scale presents challenges, including the need to adapt it for compact systems and optimize processes for both efficiency and feasibility. This study investigates the use of a corona discharge ozone generator operating at 60 Hz in compact systems. Experiments evaluated ozone production at different gas flow rates (0.2 to 1.0 L of ozone-containing gas per minute), with the total flow divided between two lines, A (60%) and C (40%), for simultaneous treatment applications. Mass balance tests were performed using caffeine (CAF) and atenolol (ATL) as model compounds to assess molecular interactions. The results highlight the need to stabilize ozone generation to ensure consistent production and process efficiency, confirming ozone’s effectiveness in degrading emerging compounds (ECs), CAF and ATL, by approximately 80%, after process optimization using the compact ozonation unit. Key factors such as the position and diameter of the flow divider, diffuser type, and pollutant characteristics were shown to affect gas distribution, head loss, and ozone transfer efficiency. Thus, this work underscores the critical role of system configuration in optimizing ozonation, offering insights to enhance its feasibility for providing safe potable water during water crises and emergencies in Brazil. Full article

Poorly differentiated thyroid malignancy, a rare histological type of aggressive thyroid malignancy with associated difficulties and gaps in its histological and molecular characterization, might lead to challenging clinical presentations that require a prompt multimodal approach. This case study involved a 56-year-old, non-smoking male with a rapidly developing goiter (within 2–3 months) in association with mild, non-specific neck compressive symptoms. His medical history was irrelevant. A voluminous goiter with substernal and posterior extension up to the vertebral bodies was detected using an ultrasound and computed tomography (CT) scan and required emergency thyroidectomy. He had normal thyroid function, as well as negative thyroid autoimmunity and serum calcitonin. The surgery was successful upon “Y” incision, which was used to give better access to the retrosternal component in order to avoid a sternotomy. Post-operatively, the subject developed hypoparathyroidism-related hypocalcemia and showed a very high serum thyroglobulin level (>550 ng/mL). The pathological report confirmed poorly differentiated, multifocal thyroid carcinoma (with an insular, solid, and trabecular pattern) against a background of papillary carcinoma (pT3b, pN0, and pM1; L1; V2; Pn0; R1; and stage IVB). The subject received 200 mCi of radioiodine therapy for 6 weeks following the thoracic surgery. Whole-body scintigraphy was performed before radioiodine therapy and showed increased radiotracer uptake at the thyroid remnants and pre-tracheal levels. Additionally, single-photon emission computed tomography combined with CT (SPECT/CT) was performed, and confirmed the areas of intense uptake, in addition to a moderate uptake in the right and left pulmonary parenchyma, suggesting lung metastasis. To conclude, an overall low level of statistical evidence exists regarding poorly differentiated malignancy in substernal goiters, and the data also remains scarce regarding the impact of genetic and molecular configurations, such as the BRAF-positive profile, in this specific instance. Furthermore, multimodal management includes additional diagnosis methods such as SPECT/CT, while long-term multilayered therapy includes tyrosine kinase inhibitors if the outcome shows an iodine-resistant profile with a poor prognosis. Awareness remains a key factor in cases of a poorly differentiated carcinoma presenting as a rapidly growing goiter with substernal extension in an apparently healthy adult. A surgical approach, while varying with the surgeon’s skills, represents a mandatory step to ensure a better prognosis. In addition to a meticulous histological characterization, genetic/molecular features provide valuable information regarding the outcome and can further help with the decision to use new anti-cancer drugs if tumor response upon radioiodine therapy is no longer achieved; such a development is expected in this disease stage in association with a BRAF-positive configuration. Full article

In recent years, the generation of circularly polarized attosecond pulses has garnered significant attention due to their potential applications in ultrafast spectroscopy and, notably, in chiral-sensitive molecular detection. The traditional methods for generating such pulses often involve complex laser configurations or specially engineered targets, limiting their experimental feasibility. In this study, we present a streamlined and effective approach to producing circularly polarized attosecond pulses by employing a linearly polarized laser field in conjunction with a stereosymmetric linear molecule, 1-butyne (C₄H₆). The generation of high-order harmonics by this molecular system reveals a distinct plateau in the perpendicular polarization component, which facilitates the generation of isolated attosecond pulses with circular polarization. Through a detailed analysis of the time-dependent charge density dynamics across atomic sites, we identify the atoms primarily responsible for the emission of circularly polarized harmonics in the plane orthogonal to the driving field. Moreover, we explore the role of multi-orbital contributions in shaping the polarization properties of the harmonic spectra. Our findings underscore the importance of molecular symmetry and the electronic structure in tailoring the harmonic polarization, and they demonstrate a viable pathway for using circularly polarized attosecond pulses to probe molecular chirality. This method offers a balance between simplicity and performance, opening new avenues for practical applications in chiral recognition and ultrafast stereochemical analysis. Full article

The paradigm of molecular-network conformations in Se-rich glassy arsenoselenides As_xSe_100−x compositionally approaching pure Se (x < 10) is considered, employing comprehensive XRD analysis of diffuse peak-halos and nanocrystalline reflections from the known Se polymorphs in their XRD patterns. Within a modified microcrystalline model, the changes with growing Se content in these alloys are interpreted in terms of suppression in intermediate range ordering due to shifting to high diffraction angles and a narrowed FSDP (first sharp diffraction peak)-related diffuse peak-halo, accompanied by enhancement in extended range ordering due to a shift to low diffraction angles and a broadened SSDP (second sharp diffraction peak)-related peak-halo. Overlapping of these peak-halos is enhanced in Se-rich alloys, tending towards unified FSDP-SSDP-related halos with characteristic doublet asymmetry due to the remnants of nanocrystalline trigonal t-Se. Drastic enhancement of the crystallization processes related to the trigonal t-Se phase is a principal feature of nanostructurization effects in Se-rich glassy arsenoselenides driven by nanomilling. The nanostructurization response in these alloys is revealed as a fragmentation impact on the correlation length of the FSDP-responsible entities, accompanied by an agglomeration impact on the correlation length of the SSDP-responsible entities. The FSDP- and SSDP-related diffuse peak-halos become more distinguishable in the XRD patterning of nanostructured arsenoselenides, being associated with other contributions from crystalline remnants, such as those expected in transition to glassy arsenoselenides with higher Se content. An irregular sequence of randomly distributed cis- and trans-configurated multiatomic Se linkages is visualized by ab initio quantum-chemical modeling of Se_n chain- and ring-like conformations. The most critical point of molecular-network disproportionality analysis in the examined arsenoselenide As_xSe_100−x glassy alloys obeying the chain-crossing model corresponds to x = 7 (equivalent to 93 at. % of Se in the binary As-Se system), as an equilibrium point between mixed cis-trans-configurated Se₇ chains and exceptionally cis-configurated molecular Se₈ rings. At the basis of developed models, the paradigm of thermodynamically stable molecular-network conformations in the nanostructured Se-rich arsenoselenides As_xSe_100−x (x < 10) is surely resolved in favor of chain-like network-forming conformations composed of mixed cis-trans-configurated network-forming multiatomic Se fragments. Full article

Solvent-exchange-induced in situ forming gel (ISG) refers to a drug delivery system that transforms from a solution state into a gel or solid matrix upon administration into the body and exposure to physiological aqueous fluid. This study investigates the molecular behavior and phase inversion process of cellulose acetate butyrate (CAB)-based in situ forming gel (ISG) formulations containing moxifloxacin (Mx) or benzydamine HCl (Bz) as model drugs dissolved in N-methyl pyrrolidone (NMP) using molecular dynamics (MD) simulations and density functional theory (DFT) calculations. The simulations reveal a solvent exchange mechanism, where the diffusion of water molecules replaces NMP, driving the formation of the CAB matrix. Bz exhibited faster diffusion and a more uniform distribution compared to Mx, which aggregated into clusters due to its larger molecular size. The analysis of the root mean square deviation (RMSD) and radius of gyration confirmed the faster diffusion of Bz, which adopted a more extended conformation, while Mx remained compact. The phase transformation was driven by the disruption of CAB-NMP hydrogen bonds, while CAB–water interactions remained limited, suggesting that CAB does not dissolve in water, facilitating matrix formation. The molecular configuration revealed that drug–CAB interactions were primarily governed by hydrophobic forces and van der Waals interactions rather than hydrogen bonding, controlling the release mechanism of both compounds. DFT calculations and electrostatic potential (ESP) maps illustrated that the acetyl group of CAB played a key role in drug–polymer interactions and that differences in CAB substitution degrees influenced the stability of drug-CAB complexes. Formation energy calculations indicated that Mx-CAB complexes were more stable than Bz-CAB complexes, resulting in a more prolonged release of Mx compared to Bz. Overall, this study provides valuable insights into the molecular behavior of CAB-based Mx-, Bz-ISG formulations. Full article

The kinetics of insulin aggregation and fibril formation were studied in vitro using Scanning Electron Microscopy (SEM) and Fourier Transform Infrared (FTIR) spectroscopy. Our investigation centered on the protein’s morphological and structural changes to better understand the transient molecular configurations that occur during the lag phase. SEM images showed that, already at early incubation stages, a network of disordered pseudo-filaments, ranging in length between 200 and 500 nanometers, develops on the surface of large aggregates. At later stages, fibrils catalyzed by protein aggregates were observed. Principal Component Analysis (PCA) of the FTIR data identified signatures of intramolecular β-sheet secondary structures forming during the lag phase and at the onset of the exponential growth phase. These absorption bands are linked to secondary nucleation mechanisms due to their transient nature. This interpretation is further supported by a chemical equilibrium model, which yielded a reliable secondary nucleation rate constant, K₂, on the order of 10⁴ M⁻² s⁻¹. Full article

Herein, we rationally designed a molecular catalytic filter for effective micropollutants decontamination via peroxymonosulfate (PMS) activation. Specifically, iron phthalocanine (FePc) molecules with defined Fe–N₄ coordination were immobilized onto carbon nanotubes (CNTs), forming a hybrid catalyst that integrated molecular precision with heterogeneous catalytic properties. The resulting CNT-FePc filter achieved a 98.4% removal efficiency for bisphenol A (10 ppm) in a single-pass operation system, significantly outperforming the CNT/PMS system without FePc (41.6%). Additionally, the CNT-FePc/PMS system demonstrated remarkable resistance to performance inhibition by common water matrix components. Unlike typical radical-dominated PMS activation processes, mechanistic investigations confirmed that the CNT-FePc/PMS system selectively promoted singlet oxygen (¹O₂) generation as the primary oxidative pathway. Density functional theory (DFT) calculations revealed that PMS exhibited stronger adsorption on FePc (−3.05 eV) compared to CNT (−2.86 eV), and that FePc effectively facilitated O–O bond elongation in PMS, thereby facilitating ¹O₂ generation. Additionally, seed germination assays indicated a significant reduction in the biotoxicity of the treated effluents. Overall, this work presents a catalyst design strategy that merges molecular-level coordination chemistry with practical flow-through configuration, enabling rapid, selective, and environmentally benign micropollutant removal. Full article

This review outlines a comprehensive methodology for the research and development of heterogeneous catalytic technologies (R&D_HeCaTe). Emphasis is placed on the fundamental interactions between reactants, solvents, and heterogeneous catalysts—specifically the roles of catalytic centers and support materials (e.g., functional groups) in modulating activation energies and stabilizing catalytic functionality. Particular attention is given to catalyst deactivation mechanisms and potential regeneration strategies. The application of molecular modeling and chemical engineering analyses, including reaction kinetics, thermal effects, and mass and heat transport phenomena, is identified as essential for R&D_HeCaTe. Reactor configuration is discussed in relation to key physicochemical parameters such as molecular diffusivity, reaction exothermicity, operating temperature and pressure, and the phase and “aggressiveness” of the reaction system. Suitable reactor types—such as suspension reactors, fixed-bed reactors, and flow microreactors—are evaluated accordingly. Economic and environmental considerations are also addressed, with a focus on the complexity of reactions, selectivity versus conversion trade-offs, catalyst disposal, and separation challenges. To illustrate the breadth and applicability of the proposed framework, representative industrial processes are discussed, including ammonia synthesis, fluid catalytic cracking, methanol production, alkyl tert-butyl ethers, and aniline. Full article

Prostate cancer is among the most prevalent malignancies in men worldwide, underscoring the need for early and accurate diagnostic tools. This study presents a proof-of-concept and pilot clinical validation of a novel bioelectric impedance-based biosensor for the detection of prostate-specific antigen (PSA) in human serum. The system integrates Molecular Identification through Membrane Engineering (MIME) with the xCELLigence real-time cell analysis platform, employing Vero cells electroinserted with anti-PSA antibodies. Optimization experiments identified 15,000 cells/well as the optimal configuration for impedance response. The biosensor exhibited specific, concentration-dependent changes in impedance upon exposure to PSA standard solutions and demonstrated significant differentiation between PSA-positive and PSA-negative human serum samples relative to the clinical threshold of 4 ng/mL. The biosensor offered rapid results within one minute, unlike standard immunoradiometric assay (IRMA), while showing strong diagnostic agreement. The system’s specificity, sensitivity, and reproducibility support its potential for integration into point-of-care screening workflows. This bioelectric assay represents one of the fastest PSA detection approaches reported to date and offers a promising solution for reducing overdiagnosis while improving clinical decision-making and patient outcomes. Full article

This study evaluates the production of base oils for biolubricants using fatty acid methyl esters (FAMEs) derived from sunflower oil as the raw material. The production process involved the synthesis of oleochemical esters through a single-step alkaline transesterification reaction with a high-molecular-weight polyol, such as trimethylolpropane (TMP). To assess the effectiveness of the developed catalytic system in conducting the transesterification reactions and its impact on the properties of the final product, two types of alkaline catalysts were used. Specifically, the reactions were carried out using either Ca/TEA alkoxide or sodium methoxide as catalysts in various configurations and concentrations to determine the optimal catalyst concentration and reaction conditions. Sodium methoxide served as the commercial benchmark catalyst, while the Ca/TEA alkoxide was prepared in the laboratory. The optimal concentration of Ca/TEA was determined to be 3.0% wt. in the presence of iso-octane and 3.5% wt. under vacuum, while the corresponding concentrations of CH₃ONa for both cases were determined to be 2.0% wt. The synthesized biolubricant esters exhibit remarkable performance characteristics, such as high kinematic viscosities and low pour points—ranging from 33–48 cSt at 40 °C, 7.68–10.03 cSt at 100 °C, to −14 to −7 °C, respectively—which are comparable to or improved over those of mineral oils such as SN-150 or SN-500, with the Ca/TEA alkoxide-catalyzed systems showing superior oxidation stability and reduced byproduct formation. Full article