A facile synthesis of monodisperse CoFe2O4/SiO2 nanoparticles

Aminated-CoFe₂O₄/SiO₂ magnetic nanoparticles (NPs) were prepared from primary silica particles using modified StÖber method. By optimizing the preparation conditions, monodisperse CoFe₂O₄/SiO₂ NPs with high amino groups’ density were obtained, which is necessary for enzyme immobilization. TEM confirm that the sample is a core/shell structure. These aminated-CoFe₂O₄/SiO₂ NPs have narrow size distributions with a mean size of about 60 nm. Moreover, the aminated-CoFe₂O₄/SiO₂ NPs can be easily dispersed in aqueous medium. The experimental results also show that the NPs have superparamagnetism, indicating that the aminated-CoFe₂O₄/SiO₂ NPs can be used as an effective carrier for the enzyme immobilization.     

Design,Synthesis and Biological Evaluation of 1,3,5-Triazine Derivatives Targeting hA1 and hA3 Adenosine Receptor

Adenosine mediates various physiological activities in the body. Adenosine receptors (ARs) are widely expressed in tumors and the tumor microenvironment (TME), and they induce tumor proliferation and suppress immune cell function. There are four types of human adenosine receptor (hARs): hA₁, hA_2A, hA_2B, and hA₃. Both hA₁ and hA₃ AR play an important role in tumor proliferation. We designed and synthesized novel 1,3,5-triazine derivatives through amination and Suzuki coupling, and evaluated them for binding affinities to each hAR subtype. Compounds 9a and 11b showed good binding affinity to both hA₁ and hA₃ AR, while 9c showed the highest binding affinity to hA₁ AR. In this study, we discovered that 9c inhibits cell viability, leading to cell death in lung cancer cell lines. Flow cytometry analysis revealed that 9c caused an increase in intracellular reactive oxygen species (ROS) and a depolarization of the mitochondrial membrane potential. The binding mode of 1,3,5-triazine derivatives to hA₁ and hA₃ AR were predicted by a molecular docking study.     

Stereocontrolled enantioselective addition of diethylzinc to aldehydes using new chiral aminoalcohols

The new chiral β-aminoalcohols of indolinylmethanols ( 1 ) and their reduced derivatives ( 2 ) were synthesized from (S)-indoline-2-carboxylic acid. Both (R) and (S) enantiomers of the optically active secondary alcohols have been successfully obtained in high enantiomeric excess from the stereoselective addition of diethylzinc to the aldehydes catalyzed by the chiral aminoalcohols ( 1 and 2 ). The sense of the asymmetric induction and the degrees of enantioselectivities turned out to be highly dependent on the structure of the catalysts: The presence of the catalyst 1 afforded the (S)-configuration of the corresponding alcohols; on the other hand, the presence of 2 afforded the (R)-configuration of the alcohols in high enantiomeric selectivity.     

Numerical investigation on evolution of cylindrical cellular detonation

Cylindrical cellular detonation is numerically investigated by solving two- dimensional reactive Euler equations with a finite volume method on a two-dimensional self-adaptive unstructured mesh. The one-step reversible chemical reaction model is applied to simplify the control parameters of chemical reaction. Numerical results demonstrate the evolution of cellular cell splitting of cylindrical cellular detonation explored in experimentas. Split of cellular structures shows different features in the near-field and far-field from the initiation zone. Variation of the local curvature is a key factor in the behavior of cell split of cylindrical cellular detonation in propagation. Numerical results show that split of cellular structures comes from the self-organization of transverse waves corresponding to the development of small disturbances along the detonation front related to detonation instability.     

Coexisting four-wave mixing and six-wave mixing in three-level atomic system

We demonstrate the coexisting four-wave mixing (FWM) signal and six-wave mixing (SWM) signal which can be enhanced both by electromagnetically induced transparency (EIT) and optical pumping effect in a common three-level and open four-level inverted-Y type systems of ⁸⁵Rb. We also analyze the effect of optical pumping in different energy level systems by arranging laser beams and comparing the strength of the increased and reduced absorption caused by optical pumping.     

A general finite element model for numerical simulation of structure dynamics

A finite element model used to simulate the dynamics with continuum and discontinuum is presented. This new approach is conducted by constructing the general contact model. The conventional discrete element is treated as a standard finite element with one node in this new method. The one-node element has the same features as other finite elements, such as element stress and strain. Thus, a general finite element model that is consistent with the existed finite element model is set up. This new model is simple in mathematical concept and is straightforward to be combined into the existing standard finite element code. Numerical example demonstrates that this new approach is more effective to perform the dynamic process analysis in which the interactions among a large number of discrete bodies and continuum objects are included.     

Synthesis and photovoltaic properties of a star-shaped molecule based on a triphenylamine core and branched terthiophene end groups

A new star-shaped donor-acceptor molecule has been synthesized for application as the donor material in solution-processed bulk-heterojunction organic solar cells (OSCs). The molecule consists of a triphenylamine (TPA) unit as the core and a donor unit with three arms containing benzo[1,2,5]thiadiazole (BT) acceptor units and 5,5’’-dihexyl-2,2′:3′,2″-terthiophene (tTh) end groups. The molecule, denoted S(TPA-BT-tTh), exhibits a broad absorption band in the wavelength range 300-650 nm and high hole mobility of 1.1×10 -4 cm2 V -1 s 1 . An OSC device based on S(TPA-BT-tTh) as donor and [6,6]-phenyl C71 -butyric acid methyl ester (PC 70 BM) as the acceptor (1:3, w/w) exhibited a power conversion efficiency of 2.28% with a short circuit current density of 6.39 mA/cm2 under illumination of AM.1.5, 100 mW/cm2 .     

Identification of Novel Rab27a/Melanophilin Blockers by Pharmacophore-Based Virtual Screening

Melanocytes are unique cells that produce specific melanin-containing intracellular organelles called melanosomes. Melanosomes are transported from the perinuclear area of melanocytes toward the plasma membrane as they become more melanized in order to increase skin pigmentation. In this vesicular trafficking of melanosomes, Rab27a, melanophilin, and myosin Va play crucial roles in linking melanosomes to actin-based motors. To identify novel compounds to inhibit binding interface between Rab27a and melanophilin, a pharmacophore model was built based on a modeled 3D structure of the protein complex that describes the essential binding residues in the intermolecular interaction. A pharmacophore model was employed to screen a chemical library database. Finally, 25 virtual hits were selected for biological evaluations. The biological activities of 11 analogues were evaluated in a second assay. Two compounds were identified as having concentration-dependent inhibitory activity. By analyzing structure–activity relationships of derivatives of BMD-20, two hydroxyl functional groups were found to be critical for blocking the intermolecular binding between Rab27a and melanophilin.     

Pep-1 Peptide-modified liposomal carriers for intracellular delivery of gold nanoparticles

A Pep-1 peptide-modified liposomal (Pep1-Lipo) carrier system was investigated to increase the intracellular delivery of gold nanoparticles (Au NPs). Au NPs with a mean diameter of 13 nm were successfully encapsulated into the inner aqueous compartment of the novel carrier using an ethanol injection technique, reserving the distinctive optical characteristics of the surface plasmon resonance peak around 530 nm. The Au NP-loaded liposomal carrier was physically characterized as 150-170 nm in size and 45 mV in zeta potential. Dark field microscopic observation demonstrated that in vitro cellular association and/or translocation of the nanoprobes into the cells was increased by Pep1-Lipo carriers compared to bare Au NPs. In conclusion, this novel liposomal formulation is a promising platform for the intracellular delivery of metallic nanoprobes including Au NPs.