Zone conditional analysis of a freely propagating one-dimensional turbulent premixed flame

The zone conditional conservation equations are derived and validated against the DNS data of a freely propagating one-dimensional turbulent premixed flame. Conditional flow velocities are calculated by the conditional continuity and momentum equations, and a modeled transport equation for the Reynolds average reaction progress variable. An asymptotic formula for turbulent burning velocity is obtained with the effects of a finite Damköhler number accounted for as an additional factor. It is shown that flame generated turbulence is primarily due to correlations between fluctuating gas velocities and fluctuating unit normal vector on a flame surface. More investigation is required to validate general predictive capability of the derived conditional conservation equations and the relationships modeled for closure.     

Likelihood-Based Local Polynomial Fitting for Single-Index Models

The parametric generalized linear model assumes that the conditional distribution of a response Y given a d-dimensional covariate X belongs to an exponential family and that a known transformation of the regression function is linear in X. In this paper we relax the latter assumption by considering a nonparametric function of the linear combination β^TX, say η₀(β^TX). To estimate the coefficient vector β and the nonparametric component η₀ we consider local polynomial fits based on kernel weighted conditional likelihoods. We then obtain an estimator of the regression function by simply replacing β and η₀ in η₀(β^TX) by these estimators. We derive the asymptotic distributions of these estimators and give the results of some numerical experiments.     

Three-dimensional stable nonconforming parallelepiped elements for the Stokes problem

Stability result is obtained for the approximation of the stationary Stokes problem with nonconforming elements proposed by Jim Douglas Jr. et al. [Math. Model. Numer. Anal. 33 (4) (1999) 747] for the velocity with conforming bubble functions and discontinuous piecewise linear for the pressure on parallelepiped elements. Optimal order H¹ and L² error estimates are derived.     

Evolutionary screening of biomimetic coatings for selective detection of explosives

Susceptibility of chemical sensors to false positive signals remains a common drawback due to insufficient sensor coating selectivity. By mimicking biology, we have demonstrated the use of sequence-specific biopolymers to generate highly selective receptors for trinitrotoluene and 2,4-dinitrotoluene. Using mutational analysis, we show that the identified binding peptides recognize the target substrate through multivalent binding with key side chain amino acid elements. Additionally, our peptide-based receptors embedded in a hydrogel show selective binding to target molecules in the gas phase. These experiments demonstrate the technique of receptor screening in liquid to be translated to selective gas-phase target binding, potentially impacting the design of a new class of sensor coatings.     

Hollow silica nanocontainers as drug delivery vehicles

Novel hollow silica nanoparticles (HSNPs) for drug delivery vehicles were synthesized using silica-coated magnetic assemblies, which are composed of a number of Fe(3)O(4) nanocrystals, as templates. The core cavity was obtained by removal of Fe(3)O(4) phase with hydrochloric acid and subsequent calcination at a high temperature. HSNPs were modified by amine in order to introduce positive surface charge and further PEGylated for increased solubility in aqueous medium. Doxorubicin as a model drug was loaded into the HSNPs, and notable sustained drug release from HSNPs was demonstrated.     

In situ detection of live cancer cells by using bioprobes based on Au nanoparticles

We fabricate the high-performance probes based on Au nanoparticles (AuNP) for detection of live cancer cell. AuNP were synthesized with narrow sized distribution (ca. 10 nm) by Au salt reduction method and deposited onto the aminated substrate as a cross-linker and hot spot. Herein, AuNP has enabled the easy and efficient immobilization of the antibody (Cetuximab), which can selectively interact with epidermal growth factor receptor (EGFR) on the surface of epidermal cancer, as detecting moiety onto the AuNP-deposited substrate without nanolithography process. After conjugation of Cetuximab with AuNP-deposited substrate, Cetuximab-conjugated probe as a live cancer cell detector (LCCD) could detect EGFR-highexpressed A431 cells related to epithelial cancer with 54-times larger specificity and sensitivity in comparison with EGFR-deficient MCF7 cells. This implies that AuNP-based probes demonstrate abundant potentials for detection and separation of small biomolecules, cells and other chemicals.     

Preparation of orthogonally functionalized surface using micromolding in capillaries technique for the control of cellular adhesion

This study presents a simple method for the fabrication of an orthogonal surface that can be applied for cell patterning without the need to immobilize specific adhesive peptides, proteins, or extracellular matrix (ECM) for cell attachment. Micromolding in capillaries (MIMIC) produced two distinctive regions. One region contained poly(ethylene glycol)–poly(d,l-lactide) diblock copolymer (PEG–PLA) designed to provide a biological barrier to the nonspecific binding of proteins and fibroblast cells. The other region was coated with polyelectrolyte (PEL) to promote the adhesion of biomolecules including proteins and cells. Resistance to the adsorption of proteins increased with the length of PEG and PLA chains because the longer PEG chain increased the PEG layer thickness and the longer PLA chain induced stronger interaction with the PEL surface. The PEG5k–PLA2.5k (20 mg/ml) was the most efficient candidate for the prevention of protein adhesion among the PEG–PLA copolymers examined. The orthogonal functionality of prepared surfaces having PEL regions and background PEG–PLA regions resulted in rapid patterning of biomolecules. Fluorescein isothiocyanate-tagged bovine serum albumin (FITC-BSA) and fibroblast cells successfully adhered to the exposed PEL surfaces. Although methods for cell patterning generally require an adhesive protein layer on the desired area, these fabricated surfaces without adhesive proteins provide a gentle microenvironment for cells. In addition, our proposed approach could easily control patterns, sizes, and shapes at micron scale.     

Synthesis of water soluble PEGylated magnetic complexes using mPEG-fatty acid for biomedical applications

We report the successful fabrication of the various types of water soluble PEGylated magnetic complexes (PMCs) for magnetism-related biomedical applications. Various types of PMCs were synthesized and tested to accomplish phase transfer from organic to aqueous phase using monomethoxy polyethylene glycol (mPEG)-fatty acid amphiphilic block copolymers (PFs) through conjugation of the hydroxyl group of mPEG with the carboxyl group of fatty acids. We also carefully investigate their colloidal stabilities in aqueous phase according to the ratio of hydrophilic and hydrophobic lengths relying on different types of fatty acids. Synthesized PMCs clearly demonstrated high magnetic sensitivity under magnetic field as magnetic resonance (MR) contrast agents. Furthermore, PMCs exhibited sufficient cell viabilities and excellent cell affinities in an in vitro model. Our results demonstrated that our PMCs possessed the potential for highly efficient magnetism-related biomedical applications such as MR image agents, drug delivery and tracking of cells.     

Effect of amine double-functionalization on CO<Subscript>2</Subscript> adsorption behaviors of silica gel-supported adsorbents

Amine double-functionalized adsorbents were fabricated using silica gel as supports and their capabilities for CO₂ capture were examined. Aminopropyltrimethoxysilane (1N-APS), and N¹-(3-trimethoxysilylpropyl)diethylenetriamine (3N-APS) were used as grafted amine compounds, and tetraethylenepentamine and polyethyleneimine were used as impregnated species. The influence of double-functionalization method on the CO₂ adsorption performance and textural properties of adsorbents was investigated. The adsorption capacity, the amine efficiency, and the thermal stability of double-functionalized sorbents depend strongly upon molecular variables associated with two different functional states (i.e., chemically grafted and physically impregnated amines). The temperature dependence of adsorption isotherms reveals that the CO₂ adsorption behavior in the double-functionalized adsorbents follow the diffusion limitation model proposed by Xu et al. (Energy Fuels 16:1463–1469, 2002) where the CO₂ adsorption is helped by the diffusion of impregnated amines. It is also found that the adsorption isotherm in the double-functionalized sorbent system with a proper choice for grafted and impregnated amines is nearly independent of temperature, which may offer a novel means to fabricate practically useful sorbents that can be used in a wide range of temperature without loss of CO₂ adsorption capacity.     

A Dipolar Anthracene Dye: Synthesis,Optical Properties and Two‐photon Tissue Imaging

Two‐photon microscopy is a powerful tool for studying biological systems. In search of novel two‐photon absorbing dyes for bioimaging, we synthesized a new anthracene‐based dipolar dye (anthradan) and evaluated its two‐photon absorbing and imaging properties. The new anthradan, 9,10‐bis(o‐dimethoxy‐phenyl)‐anthradan, absorbs and emits at longer wavelengths than acedan, a well‐known two‐photon absorbing dye. It is also stable under two‐photon excitation conditions and biocompatible, and thus used for two‐photon imaging of mouse organ tissues to show bright, near‐red fluorescence along with negligible autofluorescence. Such an anthradan thus holds promise as a new class of two‐photon absorbing dyes for the development of fluorescent probes and tags for biological systems.