Surface roughness modeling of CBN hard steel turning

Study in the paper investigate the influence of the cutting conditions parameters on surface roughness parameters during turning of hard steel with cubic boron nitrite cutting tool insert. For the modeling of surface roughness parameters was used central compositional design of experiment and artificial neural network as well. The values of surface roughness parameters Average mean arithmetic surface roughness (Ra) and Maximal surface roughness (Rmax) were predicted by this two-modeling methodology and determined models were then compared. The results showed that the proposed systems can significantly increase the accuracy of the product profile when compared to the conventional approaches. The results indicate that the design of experiments modeling technique and artificial neural network can be effectively used for the prediction of the surface roughness parameters of hard steel and determined significantly influential cutting conditions parameters

Is Sm3Fe5O12 Really Cubic at Room Temperature?

A sample of Sm3Fe5O12 was sintered from corresponding mixed hydroxides that were obtained by coprecipitation of mixed nitrates. The x-ray diffraction experiment was done with monochromatized CuKα radiation at room temperature. The sample crystallizes in the garnet structure type. The iron ions occupy both the tetrahedral and octahedral positions, while the samarium cations occupy the dodecahedral position. The refinements were done in the cubic space group Ia3d and the rhombohedral space group R-3c with a hexagonal axis. Note that the group R-3c is a subgroup of the symmetry group of the magnetic moment and subgroup of the Ia3d group. The transformation of the refined atomic coordinates from the group Ia3d into the group R-3c gives the same values, within the sum of standard deviations, as the values obtained from the refinement in the rhombohedral space group. The Debye temperatures, obtained from thermal displacement B-factors, are 320 and 560 K from the refinements in the cubic and the rhombohedral space group, respectively. The later temperature agrees with the Debye temperature obtained by independent measurements

Supplementary data for article: Marković, V.; Markovic, S.; Janicijevic, A.; Rodić, M.; Leovac, V. M.; Todorović, N.; Trifunović, S. S.; Joksović, M. D. Mechanistic Investigation and DFT Calculation of the New Reaction between S-Methylisothiosemicarbazide and Methyl Acetoacetate. Structural Chemistry 2013, 24 (6), 2127–2136. https://doi.org/10.1007/s11224-013-0223-3

Supplementary material for: [https://doi.org/10.1007/s11224-013-0223-3]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/1455

Reaction of a 3-aryilidene-2-thiohydantoin derivative with polymeric trans-[CuCl2(DMSO)(2)](n) complex: unexpected isomerization to dinuclear cis-[{CuCl(DMSO)(2)}(mu-Cl)](2)

The 3-arylidene-2-thiohydantoin derivative, 3-[(2-hydroxybenzylidene)amino]-2-thioxoimidazolidin-4-one, was synthesized in a two-step condensation reaction of 2-hydroxybenzaldehyde, thiosemicarbazide and ethyl chloroacetate. The ligand was structurally characterized by NMR and IR spectroscopy, as well as by elemental analysis. In the reaction of the well-known polymeric trans-[CuCl2(DMSO)(2)](n) complex with the polydentate thiohydantoin type ligand, instead of the corresponding copper thiohydantoin complex, unexpectedly, the dinuclear cis-[{CuCl(DMSO)(2)}(mu-Cl)](2) complex (1) was formed predominantly as the final stable product. The structure of the complex 1 was confirmed by single crystal X-ray diffraction analysis. The cis-complex is obtained through assisted isomerization of the trans-form, in which the thiohydantoin derivative has a crucial role

Evaluation of Cognitive Complexity of Tasks for the Topic Hydrogen Exponent in the Solutions of Acids and Bases

The aim of this study was evaluation of cognitive complexity of tasks for the topic hydrogen exponent in the solutions of acids and bases and its validation. The created procedure included an assessment of the difficulty of concepts and an assessment of their interactivity. There were 48 freshmen students enrolled in the study program Basic academic studies in chemistry. As a research instrument for assessing performance, test of knowledge was specifically constructed for this research. Each task in the test was followed by a seven-point Likert scale for the evaluation of invested mental effort. The evaluation of cognitive complexity was confirmed by a series of linear regression analysis where high values of correlation coefficients are obtained among the examined variables: student’s performance and invested mental effort (dependent variables) and cognitive complexity (independent variable)

A novel binuclear hydrazone-based Cd(II) complex is a strong pro-apoptotic inducer with significant activity against 2D and 3D pancreatic cancer stem cells

A novel binuclear Cd complex (1) with hydrazone-based ligand was prepared and characterized by spectroscopy and single crystal X-ray diffraction techniques. Complex 1 reveals a strong pro-apoptotic activity in both human, mammary adenocarcinoma cells (MCF-7) and pancreatic AsPC-1 cancer stem cells (CSCs). While apoptosis undergoes mostly caspase-independent, 1 stimulates the activation of intrinsic pathway with noteworthy down regulation of caspase-8 activity in respect to non-treated controls. Distribution of cells over mitotic division indicates that 1 caused DNA damage in both cell lines, which is confirmed in DNA interaction studies. Compared to 1, cisplatin (CDDP) does not achieve cell death in 2D cultured AsPC-1 cells, while induces different pattern of cell cycle changes and caspase activation in 2D cultured MCF-7 cells, implying that these two compounds do not share similar mechanism of action. Additionally, 1 acts as a powerful inducer of mitochondrial superoxide production with dissipated trans-membrane potential in the majority of the treated cells already after 6 h of incubation. On 3D tumors, 1 displays a superior activity against CSC model, and at 100 M induces disintegration of spheroids within 2 days of incubation. Fluorescence spectroscopy, along with molecular docking show that compound 1 binds to the minor groove of DNA. Compound 1 binds to the human serum albumin (HSA) showing that the HSA can effectively transport and store 1 in the human body. Thus, our current study strongly supports further investigations on antitumor activity of 1 as a drug candidate for the treatment of highly resistant pancreatic cancer

Supplementary material for the article: Bjelogrlić, S. K.; Todorović, T.; Cvijetić, I.; Rodić, M. V.; Vujčić, M.; Marković, S. B.; Araškov, J.; Janović, B.; Emhemmed, F.; Muller, C. D.; et al. A Novel Binuclear Hydrazone-Based Cd(II) Complex Is a Strong pro-Apoptotic Inducer with Significant Activity against 2D and 3D Pancreatic Cancer Stem Cells. Journal of Inorganic Biochemistry 2019, 190, 45–66. https://doi.org/10.1016/j.jinorgbio.2018.10.002

Supplementary material for: [https://www.sciencedirect.com/science/article/pii/S016201341830360X?via%3Dihub]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/355]Related to accepted version: [http://cherry.chem.bg.ac.rs/handle/123456789/2796

Supplementary data for article: Filipović, N. R.; Bjelogrlić, S. K.; Marinković, A.; Verbić, T.; Cvijetić, I.; Sencanski, M.; Rodić, M.; Vujčić, M.; Sladić, D.; Strikovic, Z.; et al. Zn(II) Complex with 2-Quinolinecarboxaldehyde Selenosemicarbazone: Synthesis, Structure, Interaction Studies with DNA/HSA, Molecular Docking and Caspase-8 and-9 Independent Apoptose Induction. RSC Advances 2015, 5 (115), 95191–95211. https://doi.org/10.1039/c5ra19849f

Supplementary material for: [https://doi.org/10.1039/c5ra19849f]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/1960

Zn(II) complex with 2-quinolinecarboxaldehyde selenosemicarbazone: synthesis, structure, interaction studies with DNA/HSA, molecular docking and caspase-8 and-9 independent apoptose induction

A new Zn(II)-based potential chemotherapeutic agent was synthesized from the ligand 2-quinolinecarboxaldehyde selenosemicarbazone (Hqasesc). Single crystal X-ray diffraction analysis showed that the Zn(II) complex consists of a cation [Zn(Hqasesc)(2)](2+), two perchlorate anions and one ethanol solvent molecule. The interaction of calf thymus (CT) DNA and human serum albumin (HSA) with the Zn(II) complex was explored using absorption and emission spectral methods, and also has been supported by molecular docking studies. The complex has more affinity to minor DNA groove than major, with no significant intercalation. The HSA interaction studies of the complex revealed the quenching of the intrinsic fluorescence of the HSA through a static quenching mechanism. The antitumor activity of the ligand and the complex against pancreatic adenocarcinoma cell line (AsPC-1) and acute monocytic leukemia (THP-1) cells was evaluated. Both compounds are strong concentration-dependent apoptosis inducers in THP-1 cells. While Hqasesc in AsPC-1 cells induces apoptosis only at the highest concentration, treatment with the Zn complex shows a concentration-dependent apoptotic response, where the treated cells are arrested in the G1-to-S phase accompanied with extensive activation of caspase-8 and -9. These results indicate that the ligand and Zn(II) complex display cell phenotype specific activity

Supplementary material for the article: Milošev, M. Z.; Jakovljević, K.; Joksović, M. D.; Stanojković, T.; Matić, I. Z.; Perović, M.; Tešić, V.; Kanazir, S.; Mladenović, M.; Rodić, M. V.; et al. Mannich Bases of 1,2,4-Triazole3-Thione Containing Adamantane Moiety: Synthesis, Preliminary Anticancer Evaluation, and Molecular Modeling Studies. Chemical Biology and Drug Design 2017, 89 (6), 943–952. https://doi.org/10.1111/cbdd.12920

Supporting Information: [https://doi.org/10.1111/cbdd.12920]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/2482]Related to accepted version: [http://cherry.chem.bg.ac.rs/handle/123456789/3221