Antiproliferative and Antiangiogenic Properties of New VEGFR-2-targeting 2-thioxobenzo[g]quinazoline Derivatives (In Vitro)

A series of 3-ethyl(methyl)-2-thioxo-2,3-dihydrobenzo[g]quinazolines (1–17) were synthesized, characterized, and evaluated in vitro for their antiangiogenesis VEGFR-2-targeting, antiproliferative, and antiapoptotic activities against breast MCF-7 and liver HepG2 cells. Flow cytometry was used to determine cancer-cell cycle distributions, and apoptosis was detected using annexin-V-FITC (V) and propidium iodide (PI) dyes. Fluorescence microscopy, in combination with Hoechst staining was used to detect DNA fragmentation. Most of the tested benzo[g]quinazolines demonstrated promising activity (IC₅₀ = 8.8 ± 0.5–10.9 ± 0.9 μM) and (IC₅₀ = 26.0 ± 2.5–40.4 ± 4.1 μM) against MCF-7 and HepG2, respectively. Doxorubicin was used as a reference drug. Compounds 13–15 showed the highest activity against both cancer cell lines. Differential effects were detected by cell-cycle analysis, indicating similarities in the actions of 13 and 14 against both MCF7 and HepG2, involving the targeting of G1 and S phases, respectively. Compound 15 showed similar indices against both cells, indicating that its cytotoxicity toward the examined cancer cells could be unselective. Interestingly, 14 and 15 showed the highest apoptosis (30.76% and 25.30%, respectively) against MCF-7. The DNA fragmentation results agreed well with the apoptosis detected by flow cytometry. In terms of antiangiogenesis activity, as derived from VEGFR-2 inhibition, 13 and 15 were comparable to sorafenib and effected 1.5- and 1.4-fold inhibition relative to the standard sorafenib. A docking study was conducted to investigate the interaction between the synthesized benzo[g]quinazolines and the ATP-binding site within the catalytic domain of VEGFR-2.     

Structural and optical properties of TiO2 thin films prepared by spin coating

Transparent semiconducting thin films of titanium oxide (TiO₂) were deposited on glass substrates by the sol–gel method and spin-coating technique. The physical properties of the prepared films were studied as a function of the number of spun-cast layers. The microstructure and surface morphology of the TiO₂ films were characterized by X-ray diffraction (XRD) and atomic force microscopy (AFM), with respect to the film thickness. The XRD analysis reveals that the films are polycrystalline with an anatase crystal structure and a preferred grain orientation in the (101) direction. The morphological properties were investigated by AFM, which shows a porous morphology structure for the films. The optical properties of the films were characterized by UV–Visible spectrophotometry, which shows that the films are highly transparent in the visible region and their transparency is slightly influenced by the film thickness, with an average value above 80 %. The dependence of the refractive index (n), extinction coefficient (k), and absorption coefficient (α) of the films on the wavelength was investigated. A shift in the optical band gap energy of the films from 3.75 to 3.54 eV, as a function of the film thickness, has been observed.     

Some New Pyrazole and Pyrazolopyrimidines: Synthesis and Antimicrobial Evaluation

Novel β‐enaminonitrile of 1‐(6‐phenyl‐pyridazin‐3‐yl)‐pyrazole derivative 2 was formed using (6‐phenyl‐pyridazin‐3‐yl)‐hydrazine ( 1 ) and 2‐ethoxymethylene‐malononitrile. The β‐enaminonitrile derivative 2 was in turn used as precursors for the preparation of 1‐(6‐phenyl‐pyridazin‐3‐yl)‐pyrazoles ( 3 , 9 , 11 ), 1‐(6‐phenyl ‐pyridazin‐3‐yl)‐pyrazolo[3,4‐d]pyrimidines ( 4 , 5 , 6 , 7 , 8 , 13 , 14 , 15 , 16 ) and some of their corresponding N‐acyclic nucleosides ( 17 , 18 ). All synthesized compounds were tested for their antimicrobial evaluation, and compounds 3 , 9 , 17 , and 18 showed more significant activity than the other tested compounds and some known drugs (standers).     

Integrating cylinder radiometry and photometry: Application to radiant flux and irradiance measurements

In this paper, we present the detail calculations of the indirect spectral irradiance E(λ) as a function of the spectral radiant flux Φ_t(λ) of a radiating source. This relation is used to predict the integrating cylinder irradiance for a given input radiant flux as a function of the geometrical parameters and reflectivity called “multiplier constant”. The radiation transfer within a cylindrical enclosure composed of three different surfaces, the inside circular surface and the two bases in the ends, has been examined. The configuration factor is introduced. Then all the configuration factors needed for our calculation have been given in analytical form.     

A variant of Hardy's and Miyachi's theorems for the Bessel–Struve transform

In this paper, we establish new versions of Hardy's and Miyachi's theorems for the Bessel–Struve transform.     

Some Properties of Nonstar Steps in Addition Chains and New Cases Where the Scholz Conjecture Is True

Let ℓ(n) be the smallest possible length of addition chains for a positive integer n. Then Scholz conjectured that ℓ(2ⁿ − 1) ≤ n + ℓ(n) − 1, which still remains open. It is known that the Scholz conjecture is true when ν(n) ≤ 4, where ν(n) is the number of 1's in the binary representation of n. In this paper, we give some properties of nonstar steps in addition chains and prove that the Scholz conjecture is true for infinitely many new integers including the case where ν(n) = 5.     

A double microbeam MEMS ohmic switch for RF-applications with low actuation voltage

In this paper, we propose the design of an ohmic contact RF microswitch with low voltage actuation, where the upper and lower microplates are displaceable. We develop a mathematical model for the RF microswitch made up of two electrostatically actuated microplates; each microplate is attached to the end of a microcantilever. We assume that the microbeams are flexible and that the microplates are rigid. The electrostatic force applied between the two microplates is a nonlinear function of the displacements and applied voltage. We formulate and solve the static and eigenvalue problems associated with the proposed microsystem. We also examine the dynamic behavior of the microswitch by calculating the limit-cycle solutions. We discretize the equations of motion by considering the first few dominant modes in the microsystem dynamics. We show that only two modes are sufficient to accurately simulate the response of the microsystem under DC and harmonic AC voltages. We demonstrate that the resulting static pull-in voltage and switching time are reduced by 30 and 45%, respectively, as compared to those of a single microbeam-microplate RF-microswitch. Finally, we investigate the global stability of the microswitch using different excitation conditions.     

Highly temperature responsive core-shell magnetic particles: synthesis, characterization and colloidal properties

Three new dimeric cholesterol-based compounds of A(LS)(2) type, where A stands for aromatic component, S steroid moiety, and L a linker connecting the two units, have been designed and prepared. Gelation test in 30 solvents demonstrated that the compounds can gel some of the solvents and form 37 gels, of which 16 form spontaneously at room temperature (~25 °C). These gels possess smart thixotropic properties as revealed by rheological studies. FTIR and (1)H NMR measurements revealed that hydrogen bonding is an important driving force for the formation of the gel networks. XRD analysis demonstrated that unlike commonly found layered structures adopted by dimeric cholesterol-based low-molecular mass gelators (LMMGs), one of the gelators created in this study adopts a hexagonal packing structure in its benzene gel.