Study of the Effect of Supersaturation Changes on the Growth of {100} KDP Crystal Faces

This study investigates the growth of {100} KDP crystal faces under varying supersaturation conditions of 6.2–14.7%. The findings indicate that the positions of growth rate maxima differ between experiments where supersaturation increases or decreases, with higher rates associated with decreasing supersaturation. Surface analysis via SEM and AFM revealed that higher supersaturation resulted in greater roughness. The growth rate on supersaturation dependence R(σ) for both types of experiments was best described by parabolic and power law models, indicating spiral growth. A significant percentage of crystal faces exhibited an exponent n > 2, suggesting the relevance of the multiple nucleation model. Additional analysis excluded the suggested model in favor of the polynuclear model. No significant difference was found between the arithmetic means of n values for both types of experiments, suggesting that for the investigated supersaturation range, the growth mechanism of {100} KDP crystal faces is independent of growth history

Fabrication of electrochemical sensor based on Eu2O3/rGO nanostructure for endocrine disruptor estradiol sensing. Theoretical perspective on the sensing mechanism

Accurate detection and monitoring of endocrine disruptor estradiol in clinical and environmental contexts are crucial due to its implications for health and ecological systems. In this work, we developed an electrochemical sensor based on europium oxide (Eu2O3) and reduced graphene oxide (rGO) for quantification of estradiol in aqueous solutions. Eu2O3 synthesized using the hydrothermal method formed ultrasmall and uniform nanoparticles and showed an efficient electrochemical behavior. Eu₂O₃ nanoparticles were incorporated with rGO and characterized by XRD, FTIR, SEM, and TEM. The obtained Eu₂O₃@rGO composite was drop-casted on the surface of a screen-printed carbon electrode to construct a sensor for estradiol quantification. The fabricated sensor exhibited an impressive limit of detection (0.06 µM) and a limit of quantification (0.236 µM), with a sensitivity of 2.44 µA µM⁻¹ cm⁻², using SWV. The obtained SWV curve shows the oxidation current increased during the addition of estradiol concentration from 0.1 to 30 µM. The practical applicability of the SPCE/Eu₂O₃@rGO sensor was demonstrated for detecting estradiol in tap water, river water, and saliva samples. The results obtained with the SPCE/Eu₂O₃@rGO sensor closely matched those from the UV–Vis validation method, confirming its reliability and accuracy. The developed sensor represents a promising candidate for routine environmental analysis due to its portability, lower cost, and potential for on-site and real-time monitoring

Exploring chemical bonding and dissociation: Computational perspectives with transition metal and organometallic complexes

Through selected case studies, including Pt(PF3)4, Cr(CO)6, Fe(CO)5, [Fe(CO)4]2- , Fe(CO)3(NO)−, Mn(CO)5(NCS), as well as other systems, we demonstrate how variations in ligand number, geometry, and electronic character (e.g., σ donation versus π* backdonation) decisively influence both the ground and excited state reactivity. These case studies underscore that modern computational techniques foster a detailed, chemically insightful understanding of bonding phenomena, offering the ability to predict dissociative behavior and guide the design of functional transition metal and organometallic complexes.The Final Conference of the COST Action "Multiscale Irradiation and Chemistry Driven Processes and Related Technologies" and the 12th International Symposium "Atomic Cluster Collisions

Gold nanoparticles embedded in polydimethylsiloxane (PDMS) microreactors for plasmonic enhancement of photocatalytic processes

We present an approach to utilize plasmonic (gold) nanoparticles embedded within the polydimethylsiloxane (PDMS) host toped of with a thin semiconductor layer to enhance photocatalytic processes in microfluidic devices. We chose this approach because it is technologically simple, requires minimal changes to the standard microreactor fabrication process, is cost effective and is widely available as PDMS is the most commonly used material to fabricate microfluidic devices. We analyze the influence of particle size and concentration as well as the semiconductor layer material (refractive index) on the plasmonic response of the structure. This allows us to tune the primary and secondary effects of plasmonic resonance, such as light localization, hot carrier generation, heating effect, etc., which are crucial for enhancement of photocatalytic processes

Cytotoxic Effects of Thymus serpyllum L. and Mentha × piperita L. Essential Oils on Basal Cell Carcinoma - An In Vitro Study

This study investigated the potential of Thymus serpyllum L. and Mentha × piperita L. essential oils (EOs), known for their bioactive properties, as adjunctive treatments targeting Basal cell carcinoma cancer stem cells (BCC CSCs). Primary cultures were established from ten BCC tumor samples and their distant resection margins as controls. The chemical composition of the EOs was analyzed by gas chromatography–mass spectroscopy (GC-MS) and attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR). The biological effects were evaluated via colony and spheroid formation, scratch assays, MTT and neutral red cytotoxicity assays, and qRT-PCR for Hh (SHH, PTCH1, SMO, and GLI1) and Notch (Notch1 and JAG1) gene expression. GC analysis identified thymol, p-cymene, and linalool as the main components of the EO of T. serpyllum L., and menthone and menthol in the EO of M. × piperita L. IC50 values were 262 µg/mL for T. serpyllum L. and 556 µg/mL for M. × piperita L. and were applied in all experiments. Both EOs significantly reduced CSC clonogenicity and migration (p < 0.05). The EO of T. serpyllum L. downregulated SMO and GLI1, while the EO of M. × piperita L. upregulated PTCH1, Notch1, and JAG1 (p < 0.05). These findings suggest that both EOs exhibit anticancer effects in BCC CSCs by modulating key oncogenic pathways, supporting their potential in BCC therapy

Hydrogen evolution on Ir nanoparticles supported by glassy carbon and graphene nanoplatelets

This study reports on the electrocatalytic activity of Ir nanoparticles (NPs) supported by glassy carbon (GC) and graphene nanoplatelets (GNPs) for the hydrogen evolution reaction (HER) in an acid solution. Ir/GC and Ir/GNPs catalysts were obtained by the electrochemical deposition of Ir on the two supports under the same conditions. SEM imaging revealed small, barely visible, Ir NPs highly dispersed on GC and located mainly on the edges of graphene plates on GNPs support. According to XPS analysis, the amount of the deposited Ir was 1.3 at% (15.9 wt%) in Ir/GC and 1.4 at% (16.5 wt%) in Ir/GNPs. Ir/GNPs catalyst has shown a higher HER activity, and potential for 10 mA/cm2 of −0.064 V, compared to −0.073 V for Ir/GC. The 32 mV/dec Tafel slope for Ir/GC and 38 mV/dec for Ir/GNPs indicate the Volmer-Tafel and Volmer-Heyrovski reaction pathways, respectively

Thermo-mechanical resistance of additively manufactured carbon fiber-reinforced PLA

In this work, additively manufactured composite samples based on polylactic acid reinforced with carbon fibers, were studied from the aspect of their tensile strength, impact toughness, hardness, and thermal resistance, with respect to 3D printing orientation. In this technology, it is known that the printing parameters significantly impact the realization of the prototypes or the properties of the final products. The polylactic acid filament with incorporated carbon fibers reinforcement (PLA-CF) was used in additive manufacturing process of the composite samples. The samples for thermo mechanical characterization were prepared using a BambuLab X1-Carbon 3D printer. In total, 27 tensile test samples and 27 impact test samples were examined according to the defined printing parameters: printed in 3 axes, 3 specimens for each testing, and tests were done at 3 temperatures (-30°C, +20°C and +50°C). During the realization of the samples, the layer height was 0.1 mm and the infill density was 90%. Differential scanning calorimetry was applied to determine the glass transition temperature of the material, and FTIR to examine interactions of PLA with CF. Due to the reinforcement with carbon fibers, PLA-CF has significantly better mechanical properties than the essential PLA filament. Solid parts produced by this technology are necessary nowadays for installation in places under substantial mechanical loads and require good heat resistance. The observed mechanical characteristics of the additively manufactured material provide good starting point for its potential use in the production of spare parts for automotive, nautical, sports industry as well as in lightweight aircrafts constructions and various protective materials

Influence of corrosion on mechanical characteristics of steel sample (42CrMO4)

Specific environmental conditions, such as marine environments, often influence steel applications in marine industries. These conditions are commonly simulated using a NaCl solution in order to simplify the study and eliminate the complexities of seawater's chemical and biological variability. In this study, 42CrMo4 steel samples, a widely utilized material in components subjected to static and dynamic stresses found in vehicles, engines, and machinery, were selected for analysis due to their susceptibility to various forms of corrosion. The corrosion behavior of the samples was monitored using mass loss and corrosion rate. The results were then correlated with changes in mechanical properties, including tensile strength and Brinell hardness. The study provides insight into how corrosion impacts the degradation of mechanical properties

Effects of Polypropylene and Polyethylene Terephthalate Microplastics on Trypsin Structure and Function

Ingestion is one of the main exposure routes of humans and animals to microplastics (MPs). During digestion, MPs can interact with both gastrointestinal enzymes and food proteins. This study investigated the adsorption of trypsin onto polypropylene (PP) and polyethylene terephthalate (PET) MPs, the influence of MPs on trypsin structure and activity, and the in vitro trypsin digestibility of bovine meat extract (BME) sarcoplasmic proteins and BME α-Gal-carrying allergens (α-GalA) in the presence of PP and PET MPs. Trypsin, BME and α-GalA proteins interact with MPs, resulting in the formation of a soft (SC) and hard (HC) corona. This interaction is dynamic, leading to the adsorption and desorption of protein through time. Trypsin adsorption onto MPs results in slight structural changes in the SC and bulk solution, while a trypsin fraction residing in the HC loses most of its specific activity. The presence of MPs slightly slows down the digestibility of proteins with a mass of 38 kDa, while it does not affect the digestion of α-GalA. According to our results, it is unlikely that realistic concentrations of MPs in the intestine would have significant effects on meat extract proteins’ and allergens’ digestibility by trypsin. We confirmed that during trypsin digestion, the corona on PP and PET MP is composed of BME sarcoplasmic proteins and allergenic α-Gal-carrying proteins

Food-derived bioactive pigment phycocyanobilin binds to SARS-CoV-2 spike protein both covalently and noncovalently affecting its conformation and functionality

Phycocyanobilin (PCB), tetrapyrrole chromophore of Spirulina phycocyanin, is bilirubin analog and weak thiol-modifying agent. SARS-CoV-2 spike protein (SP) has bilirubin binding pocket, lacks free sulfhydryl, but it has two pairs of functionally important semi-stable disulfides reactive towards thiol-modifying agents. We investigated covalent and noncovalent binding of PCB to SP and its receptor-binding domain (RBD) and impact of covalent PCB conjugation to RBD on structure and binding to human angiotensin-converting enzyme 2 (ACE-2). PCB shows high-affinity for SP (Ka = 2.1 × 107 M−1), moderate-affinity for RBD (Ka = 8.4 × 104 M−1) and binds covalently to SP and RBD in reaction involving thiols. PCB binding alters RBD conformation. Molecular docking identified two binding sites of PCB to SP, bilirubin/biliverdin binding site and hydrophobic pocket of RBD in vicinity of Cys432, preferential target for covalent binding in in silico covalent docking of PCB to RBD. Redox proteomics mapped reactive Cys432, Cys391 and Cys525 in RBD. PCB-modified RBD exhibited reduced ability to bind to ACE-2. This is the first study demonstrating PCB reactivity towards semi-stable disulfides of proteins lacking free sulfhydryl groups. PCB may affect functionality and structure of SP and its RBD by noncovalent and covalent binding