Photodimerizations of hydroxy- and benzoylated 4-azachalcones and quantum chemical investigation of the reactions

Photodimerization reactions of compounds 4–6 gave four new cyclobutane-containing compounds (7–9) with full control over the stereochemistry at the four stereogenic centers. These new cyclobutane-containing compounds had β-truxinic (7a), δ-truxinic (7b and 9), and ε-truxillic (8) structures. However, o-, m-, and p-hydroxy 4-azachalcones (1–3) did not give photochemical cyclization products under any conditions (in solvent or in their solid or molten states). Experimental data suggested the possibility of frontier orbital control over stereochemical behavior, so some theoretical calculations were performed. Full geometrical optimization of compounds 1–9 was performed via DFT B3LYP/6-31⁺G**, and their electronic structures were also investigated. The geometries of the singlet and triplet states were initially optimized by density functional theory (DFT) and the configuration interaction singles (CIS) B3LYP/3-21⁺G** level. An additional calculation was performed for the triplet state using the ground-state geometry. The possible photochemical dimerization products of compounds 7–9 (a–g) and the intrinsic reaction coordinates (IRCs) of the reactions of compounds 4–6 were calculated theoretically by the DFT/3-21⁺G** method. The configurations (reactant, transition state, product, and reaction pathway) corresponding to the stationary points (minima or saddle points) were determined. The intrinsic reaction coordinates were followed to verify the energy profiles that connect each TS to the appropriate local minimum. The dimeric products expected from the calculations coincided with the dimers produced experimentally.     

Mutagenicity of five food additives in Ames/Salmonella/microsome test

The mutagenic activity of five food additives (K₂S₂O₅: potassium metabisulphite, KMB; K₂SO₄: potassium sulphate, KS; Na₂SO₃: sodium sulphite, SS; KNO₃: potassium nitrate, KN; NaNO₃: sodium nitrate, SN) were investigated using histidin auxotrophs TA98 and TA100 strains ofSalmonella typhimurium in the presence or absence of S9 mix. The test substance were investigated for their mutagenic effects at non toxic concentrations of 0.83, 1.66, 3.33 and 5.00 mg/plate with and without S9 mix. All the test substances were not mutagenic on TA98 and TA100 strains ofSalmonella typhimurium in the presence or absence of S9 mix except KS and SN. KS and SN showed a weak mutagenic effect on TA100 strain in the absence of S9 mix.     

Reduction of plantar heel pressures: Insole design using finite element analysis

Plantar heel pain is a common condition that is often exacerbated by the repetitive stresses of walking. Treatment usually includes an in-shoe intervention designed to reduce plantar pressure under the heel by using insoles and a variety of off-the-shelf products. The design process for these products is often intuitive in nature and does not always rely on scientifically derived guidelines. Finite element analysis provides an efficient computational framework to investigate the performance of a large number of designs for optimal plantar pressure reduction. In this study, we used two-dimensional plane strain finite element modeling to investigate 27 insole designs. Combinations of three insole conformity levels (flat, half conforming, full conforming), three insole thickness values (6.3, 9.5 and 12.7 mm) and three insole materials (Poron Cushioning, Microcel Puff Lite and Microcel Puff) were simulated during the early support phase of gait. Plantar pressures predicted by the model were validated by experimental trials conducted in the same subject whose heel was modeled by loading the bare foot on a rigid surface and on foam mats. Conformity of the insole was the most important design variable, whereas peak pressures were relatively insensitive to insole material selection. The model predicted a 24% relief in pressure compared to barefoot conditions when using flat insoles; the reduction increased up to 44% for full conforming insoles.     

Effects of some drugs on purified human erythrocyte CuZnSOD and in vitro inhibitiory effect of 5-fluorouracil on leukocyte total SOD activity

The inhibition and activation effects of some drugs on the activities of superoxide dismutase enzymes (SOD) in human erythrocyte and leukocyte cells was investigated. Firstly, CuZnSOD enzyme was purified 837-fold and 12% efficiency from human erythrocytes by ethanol-chloroform treatment to remove hemoglobin and then ion exchange chromatography (DEAE-Sepharose) and copper chelate affinity chromatography techniques. Inhibition or activation effects of fourteen drugs on CuZnSOD was investigated. None of the studied drugs except for 5-fluorouracil showed any effects on the enzyme. 5-fluorouracil showed activation effects on CuZnSOD at 3.33mg/ml and 4mg/ml concentrations with 33% and 32% activation, respectively. Leukocytes were isolated from healthy human blood, lysed in liquid nitrogen and the effect of 5-fluorouracil on the lysate SOD activity investigated. 5-Fluorouracil showed inhibition effects on total SOD activity of human leukocytes at 2 mg/ml and 4 mg/ml concentrations with 42% and 62% inhibition, respectively.     

Syntheses and evaluation of multicaulin and miltirone-like compounds as antituberculosis agents

Four multicaulin and miltirone-like phenanthrene derivatives were synthesised and evaluated as antituberculosis agents. The crucial step of the synthesis was Pschorr coupling of 4-(3-isopropyl-4-methoxyphenyl)-2-(2-aminophenyl)ethane (13) to give 2-isopropyl-3-methoxy-9,10-dihydrophenanthrene (9) and 4-isopropyl-3-methoxy-9,10-dihydrophenanthrene (9a). Compound 9 was converted to multicaulin and miltirone-like phenanthrene derivatives by further reactions. The best antituberculosis activity was exhibited by 2-isopropylphenanthrene-3-ol (11).     

Effects of the nitrogen doping configuration and site on the thermal conductivity of defective armchair graphene nanoribbons

The influence of the nitrogen (N) doping configuration on the thermal conductivity (TC) of armchair graphene nanoribbons (AGNRs) of size 15.7 nm × 7.26 nm was investigated using classical molecular dynamics (MD) simulations with the optimized Tersoff potential at room temperature. The effect of changing the N-doping site in defects on the TC of AGNRs was also investigated in detail. The variations with N concentration of the TCs of AGNRs presenting graphitic N (quarternary N), pyridinic N, and pyrrolic N doping configurations were studied. Results of MD simulations showed that, among these three doping configurations, pyridinic N was associated with the highest TC, and pyrrolic N with the lowest TC. The highest TC values were obtained when the N dopant atoms were located at the edges and at defects in the AGNR. The presence of both pyrrolic N and Stone–Wales type 1 (SW-1) defects led to a higher TC than the presence of both pyrrolic N and SW-2 defects. Phonon–defect scattering was found to be influenced by changes in C–C bond orientation. SW-1 defects were found to exert a greater influence on the TC than graphitic N doping. Furthermore, the influence on the TC of the N-doping site location in SW-1 defects was examined. Doping the central sites of SW-1 defects was found to yield higher TC values than doping the edge sites of defects. Graphitic-N doping of the more central sites in a SW-1 defect led to a higher TC than the random graphitic-N doping of sites in a SW-1 defect.     

Biomechanical comparison of sinus floor elevation and alternative treatment methods for dental implant placement

Objective: In this study, we compared the success of sinus lifting and alternative treatment methods in applying dental implants in cases lacking adequate bone due to pneumatization of the maxillary sinus. Methods: In a computer environment, 3D models were created using computerized tomography data from a patient. Additionally, implants and abutments were scanned at the macroscopic level, and the resulting images were transferred to the 3D models. Five different models were examined: a control model, lateral sinus lifting (LSL), short dental implant placement (SIP), tilted implant placement (TIP) and distal prosthetic cantilever (DC) use. Vertical and oblique forces were applied in each model. The compression, tension and von Mises stresses in each model were analyzed by implementing a finite element analysis method. Results: In our study, the LSL method was observed to be the closest to the control model. The TIP model showed high stress values under conditions of oblique forces but showed successful results under conditions of vertical forces, and the opposite results were observed in the SIP model. The DC model provided the least successful results among all models. Conclusions: Based on the results of this study, the LSL method should be the first choice among treatment options. Considering its successful results under conditions of oblique forces, the SIP method may be preferable to the TIP method. In contrast, every effort should be made to avoid the use of DCs.     

Caveolin-1 polymorphisms in patients with severe obstructive sleep apnea

Objective: To investigate the associations of G14713A and T29107A polymorphic variants of Caveolin-1 with severe obstructive sleep apnea (OSA).

Materials and methods: This study was performed on 86 severe OSA patients and 86 controls. Genotyping was performed to investigate the association of G14713A and T29107A polymorphisms of Caveolin-1 with severe OSA.

Results: The distribution of genotypes of T29107A was significantly different between controls and OSA patients with a higher proportion of TT carriers in the OSA group.

Conclusion: T29107A-specific genotype of Caveolin-1 may be linked with severe OSA pathogenesis.