1,268 research outputs found
(Formato-κ2 O,O′)bis(1,10-phenanthroline-κ2 N,N′)manganese(II) perchlorate
In the title complex, [Mn(CHO2)(C12H8N2)2]ClO4, the MnII cation is chelated by two 1,10-phenanthroline (phen) ligands and one formate anion in a distorted MnN4O2 octahedral geometry. The two phen planes are oriented at a dihedral angle of 57.48 (11)°. The perchlorate anion links with the Mn complex cation via weak C—H⋯O hydrogen bonding
Design and Synthesis of Novel Anticancer Peptide Nanoparticles
Cancer has now become a common disease affecting human health. Existing cancer treatment drugs can no longer meet the growing needs of cancer patients, and the emergence of anticancer drug resistance has exacerbated this phenomenon. By designing and synthesizing new anticancer peptide nanoparticles and studying their anticancer effects, new strategies for cancer treatment may be obtained. Novel anticancer peptides are synthesized by adding basic amino acids and solid-phase synthesis technology, and their structural information is determined by mass spectrometry. Nanoparticles of anticancer peptide were synthesized by nano-self-assembly technology. Two novel anticancer peptides exhibited anticancer activity, one of which was assembled into nanoparticles. The theoretical isoelectric points of the modified SZG3 and SZG5 are all greater than physiological pH, and will be positively charged under physiological conditions. The estimated half-life of SZG3 and SZG5 is significantly extended (30h), which is beneficial to increase the efficacy and reduce toxic and side effects. SZG3 and SZG5 have a good inhibitory effect on tumor cells and have low toxicity to normal cells.
Keywords: anticancer peptide, study, design, cancer, nanoparticles 
The effect of flower position on variation and covariation in floral traits in a wild hermaphrodite plant
<p>Abstract</p> <p>Background</p> <p>Floral traits within plants can vary with flower position or flowering time. Within an inflorescence, sexual allocation of early produced basal flowers is often female-biased while later produced distal flowers are male-biased. Such temporal adjustment of floral resource has been considered one of the potential advantages of modularity (regarding a flower as a module) in hermaphrodites. However, flowers are under constraints of independent evolution of a given trait. To understand flower diversification within inflorescences, here we examine variation and covariation in floral traits within racemes at the individual and the maternal family level respectively in an alpine herb <it>Aconitum gymnandrum </it>(Ranunculaceae).</p> <p>Results</p> <p>We found that floral traits varied significantly with flower position and among families, and position effects were family-specific. Most of the variance of floral traits was among individuals rather than among flowers within individuals or among families. Significant phenotypic correlations between traits were not affected by position, indicating trait integration under shared developmental regulation. In contrast, positive family-mean correlations in floral traits declined gradually from basal to distal flowers (nine significant correlations among floral traits in basal flowers and only three in distal flowers), showing position-specificity. Therefore, the pattern and magnitude of genetic correlations decreased with flower position.</p> <p>Conclusions</p> <p>This finding on covariation pattern in floral reproductive structures within racemes has not been revealed before, providing insights into temporal variation and position effects in floral traits within plants and the potential advantages of modularity in hermaphrodites.</p
Generalized Two-Dimensional Quaternion Principal Component Analysis with Weighting for Color Image Recognition
A generalized two-dimensional quaternion principal component analysis
(G2DQPCA) approach with weighting is presented for color image analysis. As a
general framework of 2DQPCA, G2DQPCA is flexible to adapt different constraints
or requirements by imposing norms both on the constraint function and
the objective function. The gradient operator of quaternion vector functions is
redefined by the structure-preserving gradient operator of real vector
function. Under the framework of minorization-maximization (MM), an iterative
algorithm is developed to obtain the optimal closed-form solution of G2DQPCA.
The projection vectors generated by the deflating scheme are required to be
orthogonal to each other. A weighting matrix is defined to magnify the effect
of main features. The weighted projection bases remain the accuracy of face
recognition unchanged or moving in a tight range as the number of features
increases. The numerical results based on the real face databases validate that
the newly proposed method performs better than the state-of-the-art algorithms.Comment: 15 pages, 15 figure
Prasugrel, a new medicine for preventing blockages in the arteries
Prasugrel {systematic name: 5-[(2-cyclopropylcarbonyl)(2-fluorophenyl)methyl]-4,5,6,7-tetrahydrothieno[3,2-c]pyridin-2-yl acetate}, C20H20FNO3S, is a new third-generation thienopyridine which was recently approved for clinical use as a more potent blocker of the platelet P2Y12 receptor than clopidogrel, which was previously used for this purpose. The molecule features a tetrahydrothienopyridine system with the tetrahydropyridine ring showing a half-chair conformation; the dihedral angle formed by the the planes of the benzene and thiophene rings is 83.17 (3)°
{4-Bromo-2-[3-(diethylammonio)propyliminomethyl]phenolato}diiodidozinc(II) methanol solvate
In the title complex, [ZnI2(C14H21BrN2O)]·CH3OH, the asymmetric unit consists of a mononuclear zinc(II) complex molecule and a methanol solvent molecule. The compound was derived from the zwitterionic form of the Schiff base 4-bromo-2-[3-(diethylamino)propyliminomethyl]phenol. The ZnII atom is four-coordinated by the imine N and phenolate O atoms of the Schiff base ligand and by two iodide ions in a distorted tetrahedral coordination. In the crystal structure, the methanol molecules are linked to the Schiff base molecules through N—H⋯O and O—H⋯O hydrogen bonds. One I atom is disordered over two positions in a 0.702 (19):0.298 (19) ratio
{4-Bromo-2-[2-(piperidin-1-ium-1yl)ethyliminomethyl]phenolato}diiodidozinc(II)
In the title complex, [ZnI2(C14H19BrN2O)], the ZnII atom is four-coordinated by the imine N and phenolate O atoms of the Schiff base ligand and by two iodide ions in a distorted tetrahedral coordination. In the crystal structure, molecules are linked through intermolecular N—H⋯O hydrogen bonds, forming chains running along the b axis
Diiodido[N′-(2-methoxybenzylidene)-N,N-dimethylethane-1,2-diamine]zinc(II)
In the title complex, [Zn(C12H18N2O)I2], the ZnII ion is four-coordinated by the imine N and amine N atoms of the Schiff base ligand and by two iodide ions in a distorted tetrahedral coordination
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