A vinylsilane route to trans-7a-methylhydrind-4-en-1,6-dione

A stereoselective synthesis of the title compound is described. The overall yield is 34% starting with 2-methyl-2-cyclopentenone. The trans ring-fusion stereochemistry is established by a conjugate addition/trapping sequence.     

Calculating Fractional-Parentage Coefficients for Six Body System in Translational Invariant Basis

In this paper we present an independent scheme for constructing fractional parentage coefficients using symmetry group apparatus in translationally invariantmodel space, suitable for the six-particle system composed of three-particle bi-clusters, where the presented subsystems have their own intrinsic clusterization. Simple expressions for corresponding antisymmetrization procedure are presented as well as computational results.

     

Method simplifying calculation of coefficients of fractional parentage for translationally invariant shell-model

A new procedure for large-scale calculations of the coefficients of fractional parentage (CFP) for many-particle systems is presented. The approach is based on a simple enumeration scheme for antisymmetric N particle states, and we suggest an efficient method for constructing the eigenvectors of two-particle transposition operator $P_{N_1 ,N}$ in a subspace where N ₁ and N ₂ = N ? N ₁ nucleons basis states are already antisymmetrized. The main result of this paper is that according to permutation operators $P_{N_1 ,N}$ eigenvalues we can distinguish totally asymmetrical N particle states from the other states with lower degree of asymmetry.     

Converging upper and lower bounds for ground-state energies of atomic nuclei

The production of K⁺-mesons in proton-nucleus collisions from 1.0 to 2.3 GeV is analyzed with respect to one-step nucleon-nucleon (NN NYK⁺) and two-step -nucleon (N K⁺YN) or pion-nucleon (N K⁺Y) production channels on the basis of a coupled-channel (CBUU) transport approach including the kaon final-state-interactions (FSI). Momentum-dependent potentials for the nucleon, hyperon and kaon in the final state are included as well as K⁺ elastic rescattering in the target nucleus. The transport calculations are compared to the experimental K⁺ spectra taken at COSY-Jülich. Our systematic analysis of K⁺ spectra from ¹²C, ⁶³Cu, ¹⁰⁷Ag and ¹⁹⁷Au targets as well as their momentum differential ratios gives a repulsive K⁺ potential of 20±5 MeV at normal nuclear matter density.     

Sol-gel chemistry approach in the preparation of precursors for the substituted superconducting oxides

Sol-gel processing of ceramic materials for advanced applications involves several steps starting from precursor synthesis and ending up with multicomponent metal oxides. A simple sol-gel synthesis technique has been refined to prepare the precursors for the superconducting (Y_1−xSc_x)Ba₂Cu₄O₈ and (Y_1−xGa_x)Ba₂Cu₄O₈ compounds. The amorphous gel powders were characterized by powder X-ray diffraction, infrared spectroscopy, thermal analysis and elemental analysis. A systematic characterization of precursor gels led us to predict the approximate composition and the chemical reactions involved during gelation. The stability and high level of homogeneity obtained for the gels make them suitable as processable precursors to substituted (Y_1−xSc_x)Ba₂Cu₄O₈ and (Y_1−xGa_x)Ba₂Cu₄O₈ superconducting compounds.     

Metal-Organic Layer Delivers 5-Aminolevulinic Acid and Porphyrin for Dual-Organelle-Targeted Photodynamic Therapy

The efficacy of photodynamic therapy (PDT) depends on the subcellular localization of photosensitizers. Herein, we report a dual-organelle-targeted nanoparticle platform for enhanced PDT of cancer. By grafting 5-aminolevulinic acid (ALA) to a Hf₁₂-based nanoscale metal-organic layer (Hf-MOL) via carboxylate coordination, ALA/Hf-MOL enhanced ALA delivery and protoporphyrin IX (PpIX) synthesis in mitochondria, and trapped the Hf-MOL comprising 5,15-di-p-benzoatoporphyrin (DBP) photosensitizers in lysosomes. Light irradiation at 630 nm simultaneously excited PpIX and DBP to generate singlet oxygen and rapidly damage both mitochondria and lysosomes, leading to synergistic enhancement of the PDT efficacy. The dual-organelle-targeted ALA/Hf-MOL outperformed Hf-MOL in preclinical PDT studies, with a 2.7-fold lower half maximal inhibitory concentration in cytotoxicity assays in vitro and a 3-fold higher cure rate in a colon cancer model in vivo.