Two novel mononuclear copper(II) complexes, [Cu(H4N9-mpz)]Cl2·H2O (1) and [Cu(H4N9-mpz)](ClO4)2·2CH3OH (2), were synthesized for the first time utilizing the pyrazine-modulated long-chain pentapyridyltetraamine ligand, N2,N2′-(pyrazine-2,6-diyl)bis(N6-(pyridin-2-yl)pyridine-2,6-diamine) (H4N9-mpz). Both complexes were structurally characterized, and their in vitro cytotoxic activities were systematically evaluated. In each compound, the Cu(II) center is five-coordinate, adopting a slightly distorted trigonal bipyramidal geometry, with Addison distortion parameter τ values of 0.84 for complex (1) and 0.86 for complex (2). The H4N9-mpz ligand adopts an all-anti conformation, coordinating to the copper center as a pentadentate monohelical ligand. This trigonal bipyramidal coordination environment was further corroborated by electronic spectroscopy and the observation of "inverted-type" electron paramagnetic resonance (EPR) spectra. The cytotoxic effects of the free H4N9-mpz ligand and complexes 1 and 2 were evaluated against the DLD-1 and PC3 cancer cell lines, as well as the L929 healthy cell line, and compared with the reference drug cisplatin. Complex 2 exhibited superior antiproliferative activity compared to 1, yielding significantly lower IC50 values of 6.401 µM in DLD-1 cells and 2.956 µM in PC3 cells. However, toxicity profiles on healthy L929 cells revealed that complex 1 possesses a higher selectivity index than complex 2. Molecular docking simulations revealed distinct, target-dependent interaction profiles; the free ligand exhibited the highest predicted affinity toward Bcl-2, whereas the copper(II) complexes demonstrated more favorable docking scores against HSP90. These findings provide preliminary computational insights into potential ligand–protein interactions, prompting further experimental validation.
The manufacturing industry could achieve cost effectiveness, energy efficiency, time savings, personal health and safety, as well as economic and environmental sustainability by simple modifications in the design of processes. However, this can be accomplished by identifying the key points to be improved in the process. End milling, a fundamental aspect of the industry, presents an even greater challenge due to its highly dynamic, intricate (complex, nonlinear, and interdependent) and process-dependent nature. The process design comprises numerous parameters (inputs) such as machine tools, cooling and lubrication systems, cutting tools, tool holders, and workpiece characteristics. Following the selection of the workpiece material in accordance with the component to be manufactured, the cutting tool and process parameters (cutting parameters) must be adjusted to match the process. The purpose of this is to ensure the best possible optimization of the desired output. Among many outputs, surface roughness affects many features such as the tribological performance of the part, fatigue and corrosion resistance, stress concentration, and aesthetic appearance. This ostensibly complex process design can be understood through optimization methods that analyze the relationship between the specified inputs and the desired outputs for improvement. The notion that conventional optimization methods, including Taguchi, response surface methodology, analysis of variance, grey relational analysis, and statistical regression, may have limitations in addressing the growing complexity of modern applications has encouraged the use of artificial intelligence approaches as powerful alternatives. Among these sophisticated soft computing models, artificial neural network approaches have emerged prominently due to their exceptional capabilities in delivering high-accuracy processing for intricate pattern recognition and prediction problems. This review evaluates the literature chronologically on the use of artificial neural network approaches in end milling and surface roughness output, which have become popular over time. Furthermore, the objective is to review the effectiveness of ANNs rather than solely evaluating the outcomes.
Limited studies exist on the application of welded duplex stainless steel as a temporary implant material. Various methods have been employed to enhance the biocorrosion resistance and biocompatibility of metallic implant materials. In this study, the effect of welding heat input on the biocorrosion behavior and biocompatibility of AISI 2205 duplex stainless steel joined by laser beam welding was investigated. Microstructure and microtexture characterization analyses were also conducted. Electrochemical tests were performed in a simulated body fluid (SBF) environment to evaluate the biocorrosion properties of the welded samples. The results indicated that increasing the welding heat input improved corrosion resistance. This improvement was attributed to the increased austenite volume fraction, larger grain size, and a higher high-angle grain boundary (HAGB) ratio resulting from the higher heat input. Furthermore, it was observed that increasing the welding heat input decreased the water contact angle of the weld zone. In vitro biocompatibility studies were carried out using the MTT assay with an hFOB cell line. Based on the results obtained on days 7, 14, 21, and 28 of incubation, cell viability remained at acceptable levels across all groups. Metal ion release (Cr, Fe, Ni, Mn, and Mo) into the hFOB medium was analyzed using inductively coupled plasma mass spectrometry (ICP-MS), and the results showed that higher heat input reduced ion release. Finally, bacterial adhesion tests performed with Escherichia coli revealed that the welding process influenced bacterial attachment. Specifically, higher heat input promoted bacterial adhesion, which was likely associated with the increased surface roughness.
Heavy metal contamination in aquatic ecosystems poses a major threat to the environment. While nickel (Ni) plays a vital role in plant growth at low concentrations, excessive concentrations can induce toxicity, leading to genotoxicity and disrupting fundamental biological processes and cellular homeostasis in aquatic plants. This study focuses on evaluating the capacity of Alternanthera reineckii Briq (var. Lilacina), a hardy submerged aquatic plant, to remove Ni from freshwater and examines the subsequent physiological and genotoxic effects caused by Ni exposure. Samples were subjected to NiCl2.6H2O in a 0.2
Low temperature is a major environmental stress factor that limits male reproductive success in plants; however, the mechanistic basis of pollen responses to different degrees of low temperature stress remains poorly understood. In this study, we investigated the cytological, biochemical, and molecular responses of tea (Camellia sinensis) pollen grains to low-temperature stress by germinating pollen in vitro at 15, 10, and 5 °C. Although pollen germination rate and pollen tube length were reduced under all low-temperature treatments compared with the control, the underlying regulatory responses differed significantly with the severity of low-temperature stress. At 15 °C, decreases in non-enzymatic antioxidants and stress-related proteins indicated an overall metabolic weakening, while the concomitant accumulation of callose, cellulose, and methyl-esterified pectins reflected an early structural adjustment of the pollen tube cell wall. At 10 °C, the increasing stress load was partially counterbalanced by the induction of enzymatic antioxidant activities, and continued cell wall reinforcement identified this temperature as a transitional state between metabolic limitation and coordinated defense activation. In contrast, exposure to 5 °C resulted in pronounced metabolic suppression, together with a shift of stress-related proteins toward membrane fractions and enhanced deposition of callose, cellulose, and particularly de-esterified acidic pectins, leading to increased cell wall rigidity and mechanical restriction of pollen tube elongation. Overall, this study demonstrates that low-temperature stress constrains pollen tube growth not through a single limiting factor but via a temperature-dependent reorganization of interconnected cytological, biochemical, and molecular mechanisms. Low temperature reshapes tea pollen tube growth by coordinating cell wall remodeling, antioxidant defenses, and stress protein dynamics, revealing temperature specific mechanisms underlying reproductive stress tolerance.
