Expression of biologically active human \u3ci\u3ebutyrylcholinesterase\u3c/i\u3e in the cabbage looper (\u3ci\u3eTrichoplusia ni\u3c/i\u3e)

This investigation examined the utility of three recombinant protein-expression systems (COS cells, insect cells and insect larvae) to cost-effectively produce biologically active human butyrylcholinesterase (BuChE). It was determined that baculovirus-infected insect cells (Sf9 and High 5) expressed 3.5- and 8.2-fold, respectively, more active enzyme than COS-7 cells. Baculovirus-infected cabbage looper (Trichoplusia ni) insect larvae produced over 26 times more than High 5 cells ; in fact, one baculovirus-infected insect larva provided more active protein than 100 ml of insect cell culture. Analysis of the larvally expressed proteins revealed that the vast majority of BuChE expressed was inactive due to extensive degradation that occurred in vivo. However, the active form of BuChE does have enzyme kinetics similar to those of its human serum counterpart. Cabbage looper larvae were also examined for their ability to serve as an in vivo animal model to study protection against anti-cholinesterase toxicity. This was unsuccessful due to their high tolerance to the very toxic organophosphorus compounds tested. This tolerance may be attributed at least in part to a novel endogenous organophosphorus acid anhydride hydrolase activity that is capable of hydrolysing the chemical-warfare nerve agents sarin (isopropyl methylphosphonofluoridate) and soman (pinacolyl methylphosphonofluoridate). These results show that cabbage looper larvae can serve as an inexpensive recombinant protein-expression system for human BuChE

Molecular Epidemiology of Eastern Equine Encephalitis Virus, New York

Southern strains are undergoing amplification, perpetuation, and overwintering in New York

Experimental demonstration of the origin of photonic bandgap creation and associated defect modes in microwave planar circuits

This paper presents an experimental demonstration of the origin of the Photonic bandgap, using a planar dielectric substrate with a ID finite array of rectangular holes. A microstrip of uniform width placed above the array show's a periodic variation of impedance and refractive index. The measured transmission factor of the line exhibits a strong bandgap. When the width of the microstrip periodically changes in order to keep a constant impedance along the array, the bandgap in the measured transmission totally disappears. This proves that the creation of bandgap is due to the periodic variation of impedances instead of refractive indexes. The effect of the presence of defects is also illustrated. (C) 2004 Wiley Periodicals. Inc

Vibrational spectra and proton acceptor ability of 2,2-biphenyldiamine

The infrared and RAMAN spectra of 2,2'-biphenyIdiamine (BPDA) and its deuterated counterpart BPDA.-d4 are studied in the solid state and in solution and the vibrations are tentatively assigned. The complexes between BPDA and phenols are investigated in carbontetrachloride solution. The thermodynamic data (formation constants, enthalpies and entropies of complex formation) show that the BPDA complexes are somewhat stronger than the aniline complexes. The study of the NH2 stretching vibrations suggests that the hydrogen bond is formed on one of the two NH2 functions of BPDA, the second NH2 group being slightly perturbed by hydrogen bond formation on the first one

Defect modes in microstrip lines on electromagnetic bandgap substrates of finite extent

Suppression of surface waves propagating in a grounded dielectric substrate slab can be achieved by using electromagnetic band-gap (EBG) substrates. In this paper, a 2D-planar EBG substrate is investigated experimentally and simulated by a simple method based on the chain-matrix conversion. Good agreement between the measured and simulated results is observed. We also show that other defect modes can appear in the band gap, and explain their existence by, the finite size of the EBG structure under investigation. (c) 2005 Wiley Periodicals, Inc

Short-term project on microwave passive planar circuits: An educational approach

The paper presents a short-term project on microwave planar circuits proposed to undergraduate students at Universite Catholique de Louvain, Belgium, in the frame of a basic course on microwave engineering, It helps the students to familiarize with all circuit aspects at microwaves and millimeter waves: they design, analyze, realize, and measure a planar passive component operating in the frequency range 0-40 GHz. Their attention is especially focused on microwave concepts: modeling a transmission line behavior and its limitations, spurious effects at high frequencies (radiation, coupling, and reactive behavior from higher order modes), influence of etching, mechanical tolerances, and wide-band behavior. The educational relevance of the project results from the opportunity given to the students to obtain in a very short period of time an actual component by combining up-to-date theoretical models, modern etching facilities, and measurement equipment, like in industry. Such an opportunity is rather unique and of prime interest for their possible future career in the growing area of microwave and millimeter wave communications

Investigation of metamaterial leaky wave antenna based on complementary split ring resonators

This paper aims at designing an RF tag planar antenna around 2.4 GHz enabling a frequency beam steering in the plane of the substrate. The structure is based on a leaky-wave antenna topology using a transmission line with series (capacitive) gaps and CSRRs periodically loading a host microstrip line. Its behaviour is first assessed by the array factor approach using simulated S-parameters that are validated by measurements. Full-wave simulations of radiation pattern with IE3D software show that radiation occurs mainly in the plane of the substrate and is tunable with frequency.Anglai