나노입자 탐침을 이용한 탐침증강 분광법

학위논문 (석사)-- 서울대학교 대학원 : 화학부, 2016. 2. 김지환.For exploring chemical and physical properties of nanoscale objects, chemical information of single molecule and optical images with high spatial resolution is imperative. In this regard, tip-enhanced near-field optical microscopy (TENOM) is an evolving field having extensive potential. Because it provides higher spatial resolution as well as the electric field enhancement at the tip-end. This means, in other words, plasmonic enhancement and spatial confinement within the tip are critically connected to the enhanced optical signal. Therefore, we explored enhanced optical signals with various kinds of the probes to find the optimal plasmonic properties of the probes. To apply the TENOM, we use a confocal microscopy with a radially polarized light at 532 nm wavelength and an atomic force microscopy (AFM) fitted with the tip. To check the validation of our experimental setup, we first examined the radial polarizer which generates the polarization component of a laser at 532 nm parallel to the tip (z-aixs). By getting fluorescence images of nile red (in polystyrene beads with a diameter 20 nm) in both radial and azimuthal mode, we were convinced that polarization of laser was parallel to the z-axis in the focal plane. And then, experiments for tip-enhanced Raman scattering (TERS) and fluorescence (TEF) were conducted with two types of special fabricated probes which were synthesized in a similar way. In order to guarantee the our setup is available for the TERS and TEF measurements, we used a nanoparticle - a Au core/Ag shell nanoparticle (Au@AgNP) with a controlled thickness of shell - attached probe. For the synthesis of Au@AgNP probe, a seed Au nanoparticle (NP) is picked up by DNA-DNA interaction and enhanced with a silver solution were employed. For the TERS measurement, the self-assembled biphenyl-4-thiol (BPT) monolayer on Au film as the sample was employed with the Au@AgNP (size: 20-90 nm) probe. We find that such tips show high plasmonic field enhancement and this reveals clearly as size of NPs increases. For a further study, we developed a scanning probe with a metallic nanostar (a core diameter of ~70 nm and spike lengths between 50 nm and 80 nm). The approach involves AuNP pickup process and growth of spikes through reduction of Au3+ with ascorbic acid in the presence of Ag+. The nanostar probe makes the narrow enhancement field on account of its sharp edge. We find that nearly all of the tips show the local field enhancement up to 100-fold with an improved optical resolution below 100 nm for TERS and TEF was confirmed. These were evaluated with DiI dye for TEF and crystal violet for TERS. The current probe, however, shows large tip-to-tip variability, which may arise from the uncontrolled orientation of the apexes of the spike with respect to the sample surface, which calls for the further fabrication improvement. The result overall supports a new fabrication approach for the probe that is effective for tip-enhanced spectroscopy.1. Introduction 5 1.1. Tip-enhanced near-field optical microscopy 5 1.1.1. Enhanced electric field at a metallic tip 6 1.1.2. Tip-enhanced Raman scattering 8 1.1.3. Tip-enhanced Fluorescence 10 2. Experimental setup 13 2.1. Tip-enhanced near-field optical microscopy 13 2.1.1. Confocal microscopy 14 2.1.2. Polarization mode converter 17 2.2. Atomic Force Microscopy (AFM) 20 3. A Au core/Ag shell (Au@Ag) nanoparticle probes for tip-enhanced spectroscopy 23 3.1. Au@Ag nanoparticle probes 23 3.1.1. Preparation fro Au@Ag nanoparticle probes 23 3.1.2. FDTD simulated results of a silver nanoparticle 27 3.2. Sample preparation 29 3.3. TERS with regard to size of the Au@Ag nanoparticle 29 3.4. Conclusions 35 4. Nanostar probes for tip-enhanced spectroscopy 36 4.1. Nanostar probes 36 4.1.1. Synthesis of nanostars and nanostar probes 36 4.1.2. Properties of the nanostars and nanostar probes 40 4.1.2.1. Optical properties of the nanostars 40 4.1.2.2. Mechanical properties of the nanostar probes 41 4.2. Sample preparation 41 4.3. Tip-enhanced Raman scattering 46 4.4. Tip-enhanced fluorescence 51 4.5. Conclusions 54 References 56 Abstract (in Korean) 60Maste

Der Mensch zwischen Affekten, bösen Geistern und Gott

This thesis paper investigates the relation between anthropology and paraenetic instruction in the Testaments of the Twelve Patriarch, a pseudepigraphon whose provenance is highly contested (hellenistic Jewish or early Christian). It is argued that the text presupposes, up to a certain degree, human self-determination, that is, the capacity of human persons to make (moral) choices, which is necessary in order for paraenesis, or ethical teaching, to make sense in the first place. It is argued further that, according to the tenor of the paraenetical material in the Testaments of the Twelve Patriarchs, it is the creational order and indeed the very will of God that humans make use of this capacity so as to comply to the moral teachings that are delivered by the passing patriarchs. Achieving the virtues so forcefully enjoined by the patriarchs (and thereby avoiding sins often ascribed to the workings of demons or "spirits") can often be described as following the will of God. Thus, the correspondence between human self-determination (autonomy) and divine commandment/order ("theonomy" in a broader sense) can be conceived as the divinely ordained goal of human existence. It is human dependence on God that makes humans truly autonomous

Validation Study of Kim's Sham Needle by Measuring Facial Temperature: An N-of-1 Randomized Double-Blind Placebo-Controlled Clinical Trial

Introduction. In 2008, Kim's sham needle was developed to improve the quality of double-blinded studies. The aim of this study is to validate Kim's sham needle by measuring facial temperature. Methods. We designed “N-of-1” trials involving 7 smokers. One session was composed of 2 stimulations separated by a 2 h washout period. Six sessions were applied daily for all subjects. Infrared thermal imaging was used to examine the effects of acupuncture (HT8, KI2) on facial temperature following smoking-induced decrease. Results. All subjects demonstrated decreased temperatures after sham needle treatment, but 5 of the 7 subjects showed increased temperatures after real needle treatment. 6 of the 7 subjects showed a significant difference (P < 0.05) between treatments with real and sham needles. Thus, the physiological stimulation of Kim's sham needle is different from that of a real needle, suggesting that Kim's sham needle is a potential inactive control intervention

Effects of Light Color on Energy Expenditure and Behavior in Broiler Chickens

This study was conducted in order to investigate whether the presence of light or different colors of light would influence the energy expenditure and behavior of broiler chickens. Eight 8-week-old broiler chickens were adapted to a respiration chamber (Length, 28.5 cm; Height, 38.5 cm; Width, 44.0 cm) for one week prior to the initiation of the experiment. In experiment 1, energy expenditure and behavior of the chickens were analyzed in the presence or absence of light for four days. Chickens were exposed to 6 cycles of 2 h light/2 h dark period per day. In experiment 2, the broiler chickens that had been used in experiment 1 were used to evaluate the effect of 4 different wavelength light-emitting diodes (LEDs) on the energy expenditure and behavior of broiler chickens. The LEDs used in this study had the following wavelength bands; white (control), red (618 to 635 nm), green (515 to 530 nm) and blue (450 to 470 nm). The chickens were randomly exposed to a 2-h LED light in a random and sequential order per day for 3 days. Oxygen consumption and carbon dioxide production of the chickens were recorded using an open-circuit calorimeter system, and energy expenditure was calculated based on the collected data. The behavior of the chickens was analyzed based on following categories i.e., resting, standing, and pecking, and closed-circuit television was used to record these behavioral postures. The analysis of data from experiment 1 showed that the energy expenditure was higher (p<0.001) in chickens under light condition compared with those under dark condition. The chickens spent more time with pecking during a light period, but they frequently exhibited resting during a dark period. Experiment 2 showed that there was no significant difference in terms of energy expenditure and behavior based on the color of light (white, red, green, and blue) to which the chickens were exposed. In conclusion, the energy expenditure and behavior of broiler chickens were found to be strongly affected by the presence of light. On the other hand, there was no discernible difference in their energy expenditure and behavior of broiler chickens exposed to the different LED lights

Fucoxanthin, a Marine Carotenoid Present in Brown Seaweeds and Diatoms: Metabolism and Bioactivities Relevant to Human Health

The marine carotenoid fucoxanthin can be found in marine brown seaweeds, the macroalgae, and diatoms, the microalgae, and has remarkable biological properties. Numerous studies have shown that fucoxanthin has considerable potential and promising applications in human health. In this article, we review the current available scientific literature regarding the metabolism, safety, and bioactivities of fucoxanthin, including its antioxidant, anti-inflammatory, anticancer, anti-obese, antidiabetic, antiangiogenic and antimalarial activities, and its protective effects on the liver, blood vessels of the brain, bones, skin, and eyes. Although some studies have shown the bioavailability of fucoxanthin in brown seaweeds to be low in humans, many studies have suggested that a dietary combination of fucoxanthin and edible oil or lipid could increase the absorption rate of fucoxanthin, and thus it might be a promising marine drug

Theoretical and Experimental Studies of the Dechlorination Mechanism of Carbon Tetrachloride on a Vivianite Ferrous Phosphate Surface

Chlorinated organics are the principal and most frequently found contaminants in soil and groundwater, generating significant environmental problems. Over the past several decades, Fe-containing minerals naturally occurring in aquatic and terrestrial environments have been used as natural electron donors, which can effectively dechlorinate a variety of chlorinated organics. However, a full understanding of the reaction mechanism of the dechlorination pathway cannot be obtained by experimental investigations alone, due to the immeasurability of chemical species formed over a short reaction time. In this report, we describe experiments and density functional theory (DFT) calculations carried out to investigate the complex reduction pathway of carbon tetrachloride (CT) on a vivianite (Fe^(II)_3(PO_4)_2·8H_2O) surface. Our results indicate that chloroform (HCCl_3) and formate are the primary transformation products. The experimental results reveal that the reduction kinetics of CCl_4 can be dramatically accelerated as the pH is increased from 3 to 11. On the basis of the DFT calculations, we found that HCCl_3 can be formed by ^•CCl_3 and :CCl_3^(–*) on a deprotonated vivianite surface (an adsorbate on vivianite is denoted using an asterisk). In addition, :CCl_3^(–*) can be nonreductively dechlorinated to form :CCl_2^* followed by sequential nucleophilic attack by OH^(–*), resulting in the formation of :CCl(OH)^* and :C(OH)_2^*, which are responsible for production of CO and formate, respectively. The results obtained from this study can facilitate the modeling of systems of other halogenated species and minerals, which will provide fundamental insight into their corresponding reaction mechanisms

Therapeutic Effect of Chung-Pae, an Experimental Herbal Formula, on Acute Lung Inflammation Is Associated with Suppression of NF- κ

Acute lung injury (ALI) is an inflammatory disease with high mortality, but therapeutics against it is unavailable. Recently, we elaborated a formula, named Chung-pae (CP), that comprises four ethnic herbs commonly prescribed against various respiratory diseases in Asian traditional medicine. CP is being administered in aerosol to relieve various respiratory symptoms of patients in our clinic. Here, we sought to examine whether CP has a therapeutic effect on ALI and to uncover the mechanism behind it. Reporter assays show that CP suppressed the transcriptional activity of proinflammatory NF-κB and activated that of anti-inflammatory Nrf2. Similarly, CP suppressed the expression of NF-κB dependent, proinflammatory cytokines and induced that of Nrf2 dependent genes in RAW 264.7. An aerosol intratracheal administration of CP effectively reduced neutrophilic infiltration and the expression of pro-inflammatory cytokines, hallmarks of ALI, in the lungs of mice that received a prior intraperitoneal injection of lipopolysaccharide. The intratracheal CP administration concomitantly enhanced the expression of Nrf2 dependent genes in the lung. Therefore, our results evidenced a therapeutic effect of CP on ALI, in which differential regulation of the two key inflammatory factors, NF-κB and Nrf2, was involved. We propose that CP can be a new therapeutic formula against ALI

Oxygen Tension Modulates Neurite Outgrowth in PC12 Cells Through A Mechanism Involving HIF and VEGF

Cell-based approaches are a promising therapeutic strategy for treating injuries to the nervous system, but the optimal means to promote neurite extension and direct cellular behavior are unclear. Previous studies have examined the behavior of neural-like cells in ambient air (21% oxygen tension), yet these conditions are not representative of the physiological oxygen microenvironment of neural tissues. We hypothesized that neuronal differentiation of a model neural cell line (PC12) could be controlled by modulating local oxygen tension. Compared to ambient conditions, PC12 cells cultured in reduced oxygen exhibited significant increases in neurite extension and total neurite length, with 4% oxygen yielding the highest levels of both indicators. We confirmed neurite extension was mediated through oxygen-responsive mechanisms using small molecules that promote or inhibit HIF-1α stabilization. The hypoxic target gene Vegf was implicated as a neurotrophic factor, as neurite formation at 21% oxygen was mimicked with exogenous VEGF, and a VEGF-neutralizing antibody attenuated neurite formation under reduced oxygen conditions. These findings demonstrate that behavior of neural-like cells is driven by the oxygen microenvironment via VEGF function, and suggest promising approaches for future applications in neural repair