Synthesis of novel L-N-MCd4T as a potent anti-HIV agent

L-N-MCd4T (1) has been synthesized as a potent anti-HIV agent starting from (R)-epichlorohydrin using tandem alkylation, chemoselective reduction of ester in the presence of lactone functional group, RCM reaction and Mitsunobu reaction as key steps and was found to be a very potent anti-HIV-1 (EC50 = 6.76 microg mL(-1)) agent without cytotoxicity up to 100 microg mL(-1), indicating that the anti-HIV-1 activity found is similar to that of ddI (EC50 = 4.95 microg mL(-1)), which is used clinically for the treatment of AIDS patients.     

Functional SiO<Subscript>2</Subscript>–TiO<Subscript>2</Subscript>–PEG hybrid resin by direct chelation with catecholic compound

The mesoporous inorganic–organic SiO₂–TiO₂–PEG hybrid resin systems with various useful functionalities were directly synthesized by a binary sol–gel reaction of TEOS–TiCl₄ and the subsequent chelation with a chatecholic compound (dihydroxy benzene), dihydroxy-m-benzenedisulfonic acid disodium salt, on the surface Ti ion of the ordered mesoporous SBA-15 network structure, respectively. Moreover, the hybrid resins consisting of polyethylene glycol and a silane coupling agent exhibited the controlled wettability, excellent coating processibility on various substrates with strong abrasion resistance. Furthermore, the transparent and low viscous resin showed the successful performance to fabricate various nanoscale patterns with the feature size down to 170 nm by imprint lithography. Based on the excellent patternability, nanofluidics with 100 nm of the narrowest dimension channel height was fabricated to employ a capillary electrophoresis for separation DNAs without gel matrix. In addition, the presence of sulfonic acid in the resin also showed the solid acid catalytic performance. These results reveal that the developed hybrid materials are very useful as an imprint resin as well as versatile microchemical applications.     

Metabolic heat and CO2 evolution rates measured by calorimetry during different in vitro induction processes of cineraria

Explanted cotyledons from cineraria ‘Jester Pink’ seeds were cultured in vitro on a modified Murashige-Skoog medium containing (in μM): 13.5 NAA, 13.5 2,4-D, 4.4 BAP, 13.5 NAA + 4.4 BAP, 13.5 2,4-D + 4.4 BAP or no plant growth regulators (control). Photographs were taken at 7-day intervals for 35 days to follow the embryogenic/organogenic development of the explanted cotyledons. Calorespirometric (metabolic heat rate, R_q and respiration rate, RCO₂) measurements were made in triplicate on the cultured cotyledons at the same interval as the photographs. Results showed a close correlation between the embryogenic/organogenic response of the tissues and R_q values. Cotyledons on a medium containing 2,4-D + BAP had the highest R_q values while those cotyledons that failed to develop or those of control, that suffered deterioration, had the lowest. This work showed that calorespirometric data may be useful in estimating early responses of tissues/organs in vitro embryogenic/organogenic culture systems.     

Regularity of solutions for the Navier-Stokes system of incompressible flows on a polygon

We are concerned with singularities and regularities of solutions for the Navier-Stokes system of incompressible flows on a polygonal domain with a concave vertex. We subtract the corner singularities by the Stokes operator from the solution velocity and pressure functions of the system. It is shown that the stress intensity factors are functions of time variable, belong to a fractional Sobolev space on the time interval and can be expressed in terms of given data. An increased regularity for the remainder is obtained.     

Weak type estimates for some maximal operators on Hardy spaces

We show that the lacunary maximal operator associated to a compact smooth hypersurface on which the Gaussian curvature nowhere vanishes to infinite order maps the standard Hardy space H ¹ to L ^1,∞ . (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Pressure-controlled on-column injection method for microcolumn liquid chromatography.

A pressure-controlled on-column injection method was developed for microcolumn liquid chromatography. The system was assembled from a syringe pump, a Model M-445 Six-Way Micro Selection Valve, a separation column and a UV detector. The injection volume could be regulated by changing the applied pressure and/or the sample loading time. The system was evaluated in the ion-exchange mode. The system was applied to the determination of anions in river-water samples.     

A branch-and-reduce approach to global optimization

This paper presents valid inequalities and range contraction techniques that can be used to reduce the size of the search space of global optimization problems. To demonstrate the algorithmic usefulness of these techniques, we incorporate them within the branch-and-bound framework. This results in a branch-and-reduce global optimization algorithm. A detailed discussion of the algorithm components and theoretical properties are provided. Specialized algorithms for polynomial and multiplicative programs are developed. Extensive computational results are presented for engineering design problems, standard global optimization test problems, univariate polynomial programs, linear multiplicative programs, mixed-integer nonlinear programs and concave quadratic programs. For the problems solved, the computer implementation of the proposed algorithm provides very accurate solutions in modest computational time.     

Synthesis of novel polyyne analogues of sphingoid base via an iterative acetylene homologation sequence

The first syntheses of polyyne-containing sphingoid base analogues were achieved by employing our iterative strategy that uses a two-step acetylene homologation sequence. In this process, a bromoalkyne is homologated by one acetylene unit through a Pd-catalyzed cross-coupling with a TIPS-protected acetylene and a subsequent in situ AgF-mediated desilylative bromination. Repeating this homologation sequence followed by cross-coupling with the long-chained terminal acetylene provides access to the polyyne framework in good overall yields.