A Triangular Platinum(II) Multinuclear Complex with Cytotoxicity Towards Breast Cancer Stem Cells

The preparation of multinuclear metal complexes offers a route to novel anticancer agents and delivery systems. The potency of a novel triangular multinuclear complex containing three platinum atoms, Pt‐3 , towards breast cancer stem cells (CSCs) is reported. The trinuclear platinum(II) complex, Pt‐3 exhibits selective toxicity towards breast CSCs over bulk breast cancer cells and non‐tumorigenic breast cells. Remarkably, Pt‐3 inhibits the formation, size, and viability of mammospheres to a better extent than salinomycin, an established CSC‐potent agent, and cisplatin and carboplatin, clinically used platinum drugs. Mechanism of action studies show that Pt‐3 effectively enters breast CSCs, penetrates the nucleus, induces genomic DNA damage, and prompts caspase‐dependent apoptosis. To the best of our knowledge, Pt‐3 is the first multinuclear platinum complex to selectively kill breast CSCs over other breast cell types.     

Bay Functionalized Perylenediimide with Pyridine Positional Isomers: NIR Absorption and Selective Colorimetric/Fluorescent Sensing of Fe<Superscript>3+</Superscript> and Al<Superscript>3+</Superscript> Ions

Bay functionalized perylene diimide substituted with pyridine isomers, (2-pyridine (2HMP-PDI), 3-pyridine (3-HMP-PDI) and 4-pyridine (4-HMP-PDI)) have been synthesized and explored for selective coloro/fluorimetric sensing of heavy transition metal ions. HMP-PDIs showed strong NIR absorption (760–765 nm) in DMF. The absorption and fluorescence of HMP-PDIs have been tuned by make use of pyridine isomers. Reddish-orange color was observed for 2-HMP-PDI (λ_max = 437, 551, 765 nm) whereas 4-HMP-PDI exhibited light green (λ_max = 432, 522, 765 nm). 3-HMP-PDI showed orange-yellow (λ_max = 431, 524, 762 nm). The fluorescence spectra of 2-, 3- and 4-HMP-PDI showed λ_max at 585, 538, 546 nm, respectively. Interestingly, HMP-PDI dyes showed selective color change (intense pink color) and fluorescence quenching for Fe³⁺ and Al³⁺ metal ions in DMF. Absorbance spectra revealed complete disappearance of NIR absorption and intensification/appearance of new peak at lower wavelength. The concentration dependent studies suggest that 4-HMP-PDI can detect up to 36.52 ppb of Fe³⁺ and 43.12 ppb of Al³⁺ colorimetrically. The interference studies in presence of other metal ions confirmed the good selectivity for Fe³⁺ and Al³⁺. The mechanistic studies indicate that Lewis acidic character of Fe³⁺ and Al³⁺ ions were responsible for selective color change and fluorescence quenching.     

Synthesis and characterization of N,N-dimethyldodecylamine-capped Aucore-Pdshell nanoparticles in toluene

In this paper a convenient route for synthesizing Au(core)-Pd(shell) bimetallic nanoparticles in toluene has been reported as a result of co-reduction of gold(III) and palladium(II) precursors in toluene. N,N-Dimethyldodecylamine was used as a capping agent for the core-shell particles, which not only imparts stability to the organosol but also controls morphology of the evolved particles. The particles were characterized using UV-visible, transmission electron microscopy, and X-ray diffraction measurements. All results substantiate the formation of core-shell structure of the synthesized particles.     

Measuring elastic properties of bones and silicon from V(z) curve generated by multiply reflected signals

Acoustic microscopes can be used to measure Rayleigh and longitudinal or P-wave speeds in a specimen at microscopic resolution. The wave speeds are obtained from the interference pattern as a function of the defocus distance or V(z) curve. The received signal voltage amplitude Vis generated by two beams--the normally reflected central beam and a non-specularly reflected beam that strikes the fluid-solid interface at critical angle. It is shown in this paper that instead of analyzing the interference pattern between these two beams if we consider two other beams that follow the same path but travel through the coupling fluid multiple times before interfering then the V(z) curve generated by this higher order interference gives more accurate values for the material properties. The spacing distance between two successive dips of the V(z) curve is smaller for the higher order interference. The higher order interference, although weaker, gives more accurate results. Justification for the greater accuracy of the higher order interference is given in the paper. Material properties of silicon and bone are obtained by the new technique. Bones are microscopically heterogeneous and anisotropic. Anisotropic properties of homogeneous specimens can be obtained by the line focus acoustic microscope; however, it does not work when the specimen is microscopically heterogeneous. An attempt has been made here to obtain anisotropic properties of bones using point focus lens.     

Novel intramolecular rearrangement leading to the synthesis of biheterocyclic indole-benzoimidazole derivatives on solid phase

[reaction: see text] A novel intramolecular SNAr rearrangement observed during the S-alkylation of benzoimidazole-2-thione with alpha-haloacetophenone is reported. The rearrangement led to the formation of a new benzoimidazole-based intermediate, which is further utilized for the generation of a new biheterocyclic indole-benzimidazole derivatives with a two-point diversity.     

Baryogenesis and damping in nonminimal electroweak models

We calculate the baryon asymmetry of the Universe in the standard model of the electroweak theory with CP violation appropriate for simple extensions of the Higgs sector. The propagation of quarks of masses up to about 5 GeV are considered, taking into account the effect of damping rate. We find that the contribution of the b quark can still account for the observed baryon asymmetry to within the theoretical uncertainties of such models.

     

Laser optogalvanic spectroscopy of argon in the wavelength region 605–740 nm

Two-photon optogalvanic transitions in Ar glow discharge with Nd: YAG laser pumped dye laser excitation in the frequency range 13520–16520 cm⁻¹ has been studied using linear and circular polarization. The intensities of two-photon optogalvanic transitions are very sensitive to changes in the incident laser power which is not the case with one-photon transitions. Intensity ratio for circular and linear polarized light for two photon transitions 6s′[1/2]°1←4s[3/2]°2, 6s′[1/2]°0←4s[3/2]°2, and 5d[1/2]°0←4s[3/2]°2, 5d[1/2]°1←4s[3/2]°2 are quite different from the other two-photon transitions. This has been explained as due to near one photon resonance of 4p′[3/2]1 level for the first pair and 4p′[1/2]1 for the second pair of transitions. The ratio of optogalvanic intensity for circular to linear polarized light has been theoretically estimated and compared with the observed results.