Fabrication of Biomimetic Super‐Amphiphobic Surfaces Through Plasma Modification of Benzoxazine Films

Summary: In this study, a method for producing super‐amphiphobic surfaces through plasma modification of benzoxazine films is presented. Microroughening and fluorination of the benzoxazine films occurs during the plasma treatment process and a rugged surface with a micro/nano binary structure is formed. The combined effect of low surface energy and substrate roughness results in high advancing contact angles (157° for water, 152° for diiodomethane) and low contact angle hysteresis.

SEM image of a cross‐linked polybenzoxazine film treated with Ar plasma (7 min) heated to 200 °C (1 h) and treated with CF₄ plasma for 30 s.     

Dual Thermo‐ and pH‐Responsive Zwitterionic Sulfobataine Copolymers for Oral Delivery System

A novel oral delivery system consisting of thermoresponsive zwitterionic poly(sulfobetaine methacrylate) (PSBMA) and pH‐responsive poly(2‐(diisopropylamino)ethyl methacrylate) (PDPA) is synthesized via free radical polymerization. This copolymer can self‐aggregate into nanoparticles via electrostatic attraction between ammonium cation and sulfo‐anion of PSBMA and successfully encapsulate anticancer drug, curcumin (CUR), with highest loading content of 2.6% in the P(SBMA‐co‐DPA) nanoparticles. The stimuli‐responsive phase transition behaviors of P(SBMA‐co‐DPA) copolymers at different pH buffer solution show pH‐dependent upper critical solution temperature (UCST) attributed to the influence of protonation/deprotonation of the pH‐responsive DPA segments. Through the delicate adjustment of the PSBMA/PDPA molar ratios, the stimuli‐responsive phase transition could be suitable for physiological environment. The kinetic drug release profiles demonstrate that P(SBMA‐co‐DPA) nanoparticles have the potential as oral delivery carriers due to their effective release of entrapped drugs in the stimulated intestinal fluid and preventing the deterioration of drug in stimulated gastric fluid.

     

The First Heteropentanuclear Extended Metal‐Atom Chain: [Ni+Ru25+Ni2+Ni2+(tripyridyldiamido)4(NCS)2]

This study develops the first heteropentametal extended metal atom chain (EMAC) in which a string of nickel cores is incorporated with a diruthenium unit to tune the molecular properties. Spectroscopic, crystallographic, and magnetic characterizations show the formation of a fully delocalized Ru₂⁵⁺ unit. This [Ru₂]‐containing EMAC exhibits single‐molecule conductance four‐fold superior to that of the pentanickel complex and results in features of negative differential resistance (NDR), which are unobserved in analogues of pentanickel and pentaruthenium EMACs. A plausible mechanism for the NDR behavior is proposed for this diruthenium‐modulated EMAC.     

Regiospecific Coordination of Re3 Clusters with the Sumanene‐Type Hexagons on Endohedral Metallofullerenes and Higher Fullerenes That Provides an Efficient Separation Method

The reactions of [(μ‐H)₃Re₃(CO)₁₁(NCMe)] with Sc₂@C₈₂‐C_3v(8), Sc₂C₂@C₈₀‐C_2v(5), Sc₂O@C₈₂‐C_s(6), C₈₆‐C₂(17), and C₈₆‐C_s(16) have been carried out to produce face‐capping cluster complexes. The Re₃ triangles are found to bind to the sumanene‐type hexagons on the fullerene surface regiospecifically. In contrast, Sc₃N@C₇₈‐D_3h(5) and Sc₃N@C₈₀‐I_h show no reactivity toward [(μ‐H)₃Re₃(CO)₁₁(NCMe)], probably due to electronic and steric factors. These complexes can be easily purified by using HPLC. Carbonylation of each complex releases the corresponding higher fullerene or endohedral metallofullerene in pure form. Remarkably, the C₈₆‐C₂(17) and C₈₆‐C_s(16) isomers were successively separated through Re₃ cluster complexation/decomplexation. This unique bonding feature may provide an attractive general strategy to purify as yet unresolved fullerene mixtures.     

Design and Synthesis of 1‐(6‐(2‐(2‐Arylethynyl)Phenyl)Hexyn‐5‐yl)Piperidin‐2‐Ones as Antitumor Agents that Induce Apoptotic Progress

A series of 1‐(6‐(2‐(2‐arylethynyl)phenyl)hexyn‐5‐yl)piperidin‐2‐ones 2a‐j were synthesized and their antitumor activities were evaluated. Of these compounds, 1‐(6‐(2‐(2‐(4‐nitrophenyl)ethynyl)phenyl)hexyn‐5‐yl)piperidin‐2‐one ( 2j ) showed the highest potency of growth inhibition activity, especially against the RPMI‐8226 (0.4 μM) and SR (0.02 μM) cell lines of human leukemia. Compound 2j also induced significant apoptotic progress in the cell cycle assay with the K‐562 cell line.     

Stable new bound soliton pairs in a 10 GHz hybrid frequency modulation mode-locked Er-fiber laser

We report what is, to our knowledge, the first experimental observation of stable new bound soliton pairs at the 10 GHz repetition rate in a hybrid FM harmonic mode-locked Er-fiber laser (1177 soliton pairs simultaneously in the laser cavity). The two solitons in the soliton pair have the identical pulse shape and are with the antiphase (pi phase difference). Their time separation is about three times the FWHM soliton width and varies with the phase modulation strength. The corresponding mechanism for explaining the formation as well as the superior stability of these closely bound soliton pairs is also given.     

Conservative flux recovery from the Q1 conforming finite element method on quadrilateral grids

Compared with standard Galerkin finite element methods, mixed methods for second‐order elliptic problems give readily available flux approximation, but in general at the expense of having to deal with a more complicated discrete system. This is especially true when conforming elements are involved. Hence it is advantageous to consider a direct method when finding fluxes is just a small part of the overall modeling processes. The purpose of this article is to introduce a direct method combining the standard Galerkin Q1 conforming method with a cheap local flux recovery formula. The approximate flux resides in the lowest order Raviart‐Thomas space and retains local conservation property at the cluster level. A cluster is made up of at most four quadrilaterals. © 2004 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 20: 104–127, 2004