• Journal of Photoscience
• /
• v.11 no.1
• /
• pp.7-9
• /
• 2004

The synthesized macrocycle L was found to be a smart fluorescent receptor which distinguishable efficiently from various neutral molecules with the functional groups such as the electron donating (X =$CH_3$, N($CH_3$)$_2$ and O$CH_3$) and electron withdrawing groups (X =F and Cl), respectively. In the case of guest molecules containing electron donating groups, the fluorescence of macrocycle L was enhanced in the presence of the guest molecules. On the contrary, in the case of guest molecules containing electron withdrawing groups, it was almost quenched in the presence of those.

• Proceedings of the Optical Society of Korea Conference
• /
• 2001.02a
• /
• pp.272-273
• /
• 2001

We demonstrate the first separation of neutral molecules using optical forces. Unlike laser atomic cooling or optical tweezers, optical separation technique requires the manipulation of only one component of the molecular motion. Thus the mixtures can be separated, in principle, with less complex schemes. When an Intense nonresonant laser beam is focused onto a beam of molecules, the interaction between the laser electric field and the induced dipole moment of a molecule invokes a mechanical force on the molecule proportional to the field gradient and the molecular polarizability ($\alpha$) to mass (m) ratio $\alpha$/m. (omitted)

• Bulletin of the Korean Chemical Society
• /
• v.30 no.12
• /
• pp.2930-2934
• /
• 2009

Surface-enhanced Raman Scattering (SERS) spectroscopy is applied to the study of the adsorption of benzoimidazolic fungicides benzimidazole (BIZ) and thiabendazole (TBZ) on silver mirrors. The influence of pH on the adsorption mechanism was investigated. In case of BIZ, two different adsorption mechanisms are deduced depending on the experimental conditions: via the $\pi$ electrons of the ring in neutral conditions and through an ionic pairing of protonated nitrogen atom with the chloride adsorbed on the metal surface. The SERS spectra of TBZ revealed that most molecules were adsorbed on silver surface by the ${\pi}$ electrons in neutral and acidic conditions but in acid conditions, some molecules were adsorbed via the sulfur and nitrogen atoms tilted slightly to the surface.

• Proceedings of the KIEE Conference
• /
• 1987.11a
• /
• pp.412-414
• /
• 1987

Theoretical studies of concentration for negative ion and neutral species in electrical excitation discharge have been conducted at $CO_2-N_2-He=1-7-12$, total pressure 20torr. With a computer model of neutral and negative ion processes we have calculated that the concentration of co was less than 20% when expected molecular.

• Journal of Environmental Science International
• /
• v.22 no.9
• /
• pp.1153-1160
• /
• 2013

While a range of natural organic matter (NOM) types can generate high levels of disinfection by-products (DBPs) after chlorination, there is little understanding of which specific compounds act as precursors. Use of eight model compounds allows linking of explicit properties to treatability and DBP formation potential (DBPFP). The removal of model compounds by various treatment processes and their haloacetic acid formation potential (HAAFP) before and after treatment were recorded. The model compounds comprised a range of hydrophobic (HPO) and hydrophilic (HPI) neutral and anionic compounds. On the treatment processes, an ozone oxidation process was moderate for control of model compounds, while the HPO-neutral compound was most treatable with activated carbon process. Biodegradation was successful in removing amino acids, while coagulation and ion exchange process had little effect on neutral molecules. Although compared with the HPO compounds the HPI compounds had low HAAFP the ozone oxidation and biodegradation were capable of increasing their HAAFP. In situations where neutral or HPI molecules have high DBPFP additional treatments may be required to remove recalcitrant NOM and control DBPs.

• Korean Journal of Plant Tissue Culture
• /
• v.21 no.4
• /
• pp.201-206
• /
• 1994

The influx of glycine, valine, alanine, and histidine was inhibited by all tested neutral amino acids competitively and the reciprocal inhibitory studies showed the neutral amino acids possess the same transport system as neutral amino acids process to the same catalytic site of one carrier to each other, The molecules of histidine were transported actively as a neutral form through the neutral amino acid transport system but were not transported as a charged form. The Km values of the neutral amino acid transport system have been divided into three different category on basis of the affinity to the carrier, below 0.1mM, etween 0.1ImM-0.5mM and above 0.5mM. The $V_{max}$ was between $3.12{\mu}mole{\cdot}h^{-1}{\cdot}g$ fresh $weight^{-1}\;-\;15.1\;{\mu}mole{\cdot}h^{-1}{\cdot}g$ fresh $weight^{-1}$. Neutral amino acids cotransported with one $H^{+}per$ one molecule and one $K^{+}-efflux$ per one molecule for charge compensation. Histidine cotransported with proton per one molecule, however the movement of cotransported proton can't detectable because of the release of proton from the charged molecules of histidine in the medium.

• Bulletin of the Korean Chemical Society
• /
• v.34 no.4
• /
• pp.1025-1029
• /
• 2013

In the previous paper (Bull. Korean Chem. Soc., 2011, 32, 2997), the hybrid molecules between ${\alpha}$-lipoic acid (ALA) and polyphenols (PPs) connected with neutral 2-(2-aminoethoxy)ethanol linker (linker-1) showed new biological activity such as butyrylcholinesterase (BuChE) inhibition. In order to increase the binding affinity of the hybrid compounds to cholinesterase (ChE), the neutral 2-(2-aminoethoxy)ethanol (linker 1) was switched to the cationic 2-(piperazin-1-yl)ethanol linker (linker 2). The $IC_{50}$ values of the linker-2 hybrid molecules for BuChE inhibition were lower than those of linker-1 hybrid molecules (except 9-2) and they also had the same great selectivity for BuChE over AChE (> 800 fold) as linker-1 hybrid molecules. ALA-acetyl caffeic acid (10-2, ALA-AcCA) was shown as an effective inhibitor of BuChE ($IC_{50}=0.44{\pm}0.24{\mu}M$). A kinetic study using 7-2 showed that it is the same mixed type inhibition as 7-1. Its inhibition constant (Ki) to BuChE is $4.3{\pm}0.09{\mu}M$.

• Archives of Pharmacal Research
• /
• v.25 no.5
• /
• pp.704-708
• /
• 2002

A fast and sensitive protein staining method in sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) using both an acidic dye, Coomassie Brilliant Blue R-250 (CBBR) and a basic dye, Neutral Red (NR) is described. It is based on a counter ion-dye staining technique that employs oppositely charged two dyes to form an ion-pair complex. The selective binding of the free dye molecules to proteins in an acidic solution enhances the staining effect of CBBR on protein bands, and also reduces gel background. It is a rapid staining procedure, involving fixing and staining steps with short destaining that are completed in about 1 h. As the result, it showed two to fourfold increase in sensitivity comparing with CBBR staining. The stained protein bands can be visualized at the same time of staining.

• Bulletin of the Korean Chemical Society
• /
• v.22 no.8
• /
• pp.833-836
• /
• 2001

Infrared absorption spectra of $\alpha\omega-diphenylpolyenyl$, anions Ph(CH)nPh- (DPn-, n=7, 9, and 13) in the tetrahydrofuran-d6 solutions was measured in the range of 1700 and 1200 cm-1 . The infrared spectra obtained from anions (DPn) showed considerable difference from their neutral species (DPn); their intensities were enhanced at least two orders of magnitude stronger than their neutral species. The in-plane CH bending modes at 1464 and 1375 cm-1 are correspondingly strengthened with the chain length increased, but the C=C stretching at 1541 cm-1 is weakened and frequencies are not changed. We provide an IR evidence for the first time that the bond order or bond alternations of the anions (soliton) are different from those of radical anions (polaron) as well as neutral species.

• Proceedings of the Korean Society of Potoscience Conference
• /
• 2002.06a
• /
• pp.75-75
• /
• 2002