Design, Synthesis, and Characterization of Polymer and Small-Molecule Organic Semiconductors based on Tricyclic Heterocycles for Opto-Electronic Devices

Department of Energy EngineeringAs next-generation electronic applications, organic semiconductors based on organic small molecules and polymers with a π -conjugated backbone have shown remarkable results for past decades. In particular, unlike inorganic semiconductors, which have reached the limitation of development, they still have growth potentiality in both industry and academia because of advantages such as low cost, light weight, roll-to-roll (R2R) technology, and so on. Despite tremendous scientific progress, an efficient molecular design and optimization of the fabrication process is needed for further advancement and commercialization of organic electronics. In this work, in order to seek an optimal semiconducting system, organic small molecules/polymers that have various properties were designed and synthesized. The resulting small molecules and polymers were characterized via diverse analysis tools, including NMR, GPC, mass spectroscopy, MADI-TOF, UV-Vis spectrum, TGA, cyclic voltammetry, AFM, XRD, GIWAX. Furthermore, all synthesized organic materials were tested with electronic applications like organic photovoltaics (OPVs) and organic transistors. In the first chapter, the general background of conjugated conducting materials is described to more properly frame the present study. At the same time, essential chemical reactions, mechanisms, and electronic applications are introduced. The second chapter demonstrates synthesis and characterization of benzodipyrrolidone (BDP)-based polymer with electron rich units containing calcogen atoms for OFETs. Thirdly, by tuning the side chain, a powerful and facile control method, polymers based on benzodithiophene (BDT) are designed and synthesized. Subsequently, BDT-based polymer are characterized and applied as active layer of OPVs. Finally, a new class of n-channel semiconducting small molecules based on a BDT core unit, end-capped with the dicyanomethylene and dicyanovinyl groups (DCM-Q-BDT and DCV-B-BDT) was obtained, and their various properties fully analyzed. Furthermore, these molecules were applied as n-type organic transistors and their air stabilities measured.ope

Effects of Corni fructus on ovalbumin-induced airway inflammation and airway hyper-responsiveness in a mouse model of allergic asthma

<p>Abstract</p> <p>Background</p> <p>Allergic asthma is a chronic inflammatory lung disease that is characterized by airway hyperresponsiveness (AHR) to allergens, airway oedema, increased mucus secretion, excess production of T helper-2 (Th2) cytokines, and eosinophil accumulation in the lungs. Corni fructus (CF) is a fruit of <it>Cornus officinalis </it>Sieb. Et. Zucc. (Cornaceae) and has been used in traditional Korean medicine as an anti-inflammatory, analgesic, and diuretic agent. To investigate the anti-asthmatic effects of CF and their underlying mechanism, we examined the influence of CF on the development of pulmonary eosinophilic inflammation and airway hyperresponsiveness in a mouse model of allergic asthma.</p> <p>Methods</p> <p>In this study, BALB/c mice were systemically sensitized to ovalbumin (OVA) by intraperitoneal (i.p.), intratracheal (i.t.) injections and intranasal (i.n.) inhalation of OVA. We investigated the effect of CF on airway hyperresponsiveness, pulmonary eosinophilic infiltration, various immune cell phenotypes, Th2 cytokine production, and OVA-specific immunoglobulin E (IgE) production.</p> <p>Results</p> <p>The CF-treated groups showed suppressed eosinophil infiltration, allergic airway inflammation, and AHR via reduced production of interleuin (IL) -5, IL-13, and OVA-specific IgE.</p> <p>Conclusions</p> <p>Our data suggest that the therapeutic effects of CF in asthma are mediated by reduced production of Th2 cytokines (IL-5), eotaxin, and OVA-specific IgE and reduced eosinophil infiltration.</p

Antiasthmatic Effects of Hesperidin, a Potential Th2 Cytokine Antagonist, in a Mouse Model of Allergic Asthma

Background and Objective. The features of asthma are airway inflammation, reversible airflow obstruction, and an increased sensitivity to bronchoconstricting agents, termed airway hyperresponsiveness (AHR), excess production of Th2 cytokines, and eosinophil accumulation in the lungs. To investigate the antiasthmatic potential of hesperidin as well as the underlying mechanism involved, we studied the inhibitory effect and anti-inflammatory effect of hesperidin (HPN) on the production of Th2 cytokines, eotaxin, IL-17, -OVA-specific IgE in vivo asthma model mice. Methods. In this paper, BALB/c mice were systemically sensitized to ovalbumin (OVA) followed intratracheally, intraperitoneally, and by aerosol allergen challenges. We investigated the effect of HPN on airway hyperresponsiveness, pulmonary eosinophilic infiltration, various immune cell phenotypes, Th2 cytokine production and OVA-specific IgE production in a mouse model of asthma. Results. In BALB/c mice, we found that HPN-treated groups had suppressed eosinophil infiltration, allergic airway inflammation, and AHR, and these occurred by suppressing the production of IL-5, IL-17, and OVA-specific IgE. Conclusions. Our data suggest that the therapeutic mechanism by which HPN effectively treats asthma is based on reductions of Th2 cytokines (IL-5), eotaxin, OVA-specific IgE production, and eosinophil infiltration via inhibition of GATA-3 transcription factor

Hydrated copper and gold monovalent cations: Ab initio study

To understand the hydration phenomena of noble transition metals, we investigated the structures, hydration energies, electronic properties, and spectra of the Cu+(H3O)(1-6) and Au+ (H2O)(1-6) clusters using ab initio calculations. The coordination numbers of these clusters are found to be only two, which is highly contrasted to those of Ag+ (H2O)(n) (which have the coordination numbers of 3-4) as well as the hydrated alkali metal ions (which have the coordination numbers of similar to6). For the possible identification of their interesting hydration structures, we predict their IR spectra for the OH stretch modes. (C) 2005 American Institute of Physics.open384

Structure and spectral features of H+(H2O)(7): Eigen versus Zundel forms

The two dimensional (2D) to three dimensional (3D) transition for the protonated water cluster has been controversial, in particular, for H+(H2O)(7). For H+(H2O)(7) the 3D structure is predicted to be lower in energy than the 2D structure at most levels of theory without zero-point energy (ZPE) correction. On the other hand, with ZPE correction it is predicted to be either 2D or 3D depending on the calculational levels. Although the ZPE correction favors the 3D structure at the level of coupled cluster theory with singles, doubles, and perturbative triples excitations [CCSD(T)] using the aug-cc-pVDZ basis set, the result based on the anharmonic zero-point vibrational energy correction favors the 2D structure. Therefore, the authors investigated the energies based on the complete basis set limit scheme (which we devised in an unbiased way) at the resolution of the identity approximation Moller-Plesset second order perturbation theory and CCSD(T) levels, and found that the 2D structure has the lowest energy for H+(H2O)(7) [though nearly isoenergetic to the 3D structure for D+(D2O)(7)]. This structure has the Zundel-type configuration, but it shows the quantum probabilistic distribution including some of the Eigen-type configuration. The vibrational spectra of MP2/aug-cc-pVDZ calculations and Car-Parrinello molecular dynamics simulations, taking into account the thermal and dynamic effects, show that the 2D Zundel-type form is in good agreement with experiments. (c) 2006 American Institute of Physics.open353

Cancer Statistics in Korea: Incidence, Mortality, Survival, and Prevalence in 2008

PURPOSE: This paper overviews the nationwide cancer statistics including incidence, mortality, survival and prevalence, and their trends in Korea based on the year 2008 cancer incidence data. MATERIALS AND METHODS: Incidence data from 1993 to 2008 were obtained from the Korea National Cancer Incidence Database, and the vital status was followed through December 31, 2009. Mortality data from 1983 to 2008 were obtained from the Korea National Statistics Office. Crude rates and age-standardized rates for incidence, mortality, prevalence and relative survival were calculated. RESULTS: There were 178,816 cancer cases and 68,912 cancer deaths observed during year 2008 and 724,663 10-year cancer prevalent cases as of January 1, 2009 in Korea. The incidence rate for all cancer combined showed an annual increase of 3.1% from 1999 to 2008. CONCLUSION: With significantly increasing cancer incidence, Korea faces a large cancer burden and efficient cancer control programs are essential.ope

Locally Controlled Sensing Properties of Stretchable Pressure Sensors Enabled by Micro-Patterned Piezoresistive Device Architecture.

For wearable health monitoring systems and soft robotics, stretchable/flexible pressure sensors have continuously drawn attention owing to a wide range of potential applications such as the detection of human physiological and activity signals, and electronic skin (e-skin). Here, we demonstrated a highly stretchable pressure sensor using silver nanowires (AgNWs) and photo-patternable polyurethane acrylate (PUA). In particular, the characteristics of the pressure sensors could be moderately controlled through a micro-patterned hole structure in the PUA spacer and size-designs of the patterned hole area. With the structural-tuning strategies, adequate control of the site-specific sensitivity in the range of 47~83 kPa-1 and in the sensing range from 0.1 to 20 kPa was achieved. Moreover, stacked AgNW/PUA/AgNW (APA) structural designed pressure sensors with mixed hole sizes of 10/200 µm and spacer thickness of 800 µm exhibited high sensitivity (~171.5 kPa-1) in the pressure sensing range of 0~20 kPa, fast response (100~110 ms), and high stretchability (40%). From the results, we envision that the effective structural-tuning strategy capable of controlling the sensing properties of the APA pressure sensor would be employed in a large-area stretchable pressure sensor system, which needs site-specific sensing properties, providing monolithic implementation by simply arranging appropriate micro-patterned hole architectures

Learning Curve for Robot-Assisted Laparoscopic Radical Prostatectomy for Pathologic T2 Disease

Purpose: To investigate the learning curve for robot-assisted laparoscopic radical prostatectomy (RALP) for pathologic T2 disease, we examined differences in perioperative outcomes according to time period. Materials and Methods: Between July 2005 and June 2008, a total of 307 consecutive patients underwent RALP for prostate cancer and 205 patients had pathologic T2 disease. Patients were grouped into 6-month time periods. We collected and examined the patient's perioperative data including age, body mass index (BMI), prostate-specific antigen (PSA), operation time, estimated blood loss, and positive surgical margin. Results: There were no significant differences among the groups in age (p=0.705), BMI (p=0.246), PSA (p=0.425), or prostate volume (p=0.380). Operation time (p<0.001) and estimated blood loss (p<0.001) decreased significantly with time. The positive surgical margin rate also showed a decreasing trend, but this was not significant (p=0.680). Conclusions: Operation time and estimated blood loss had a steep learning curve during the early 24 cases and then stabilized. A positive surgical margin rate, however, did not have a significant learning curve, although the positive surgical margin decreased continuously. ?? the Korean Urological Association, 2010

Antioxidant and Anti-Inflammatory Effects of Shungite against Ultraviolet B Irradiation-Induced Skin Damage in Hairless Mice

As fullerene-based compound applications have been rapidly increasing in the health industry, the need of biomedical research is urgently in demand. While shungite is regarded as a natural source of fullerene, it remains poorly documented. Here, we explored the in vivo effects of shungite against ultraviolet B- (UVB-) induced skin damage by investigating the physiological skin parameters, immune-redox profiling, and oxidative stress molecular signaling. Toward this, mice were UVB-irradiated with 0.75 mW/cm2 for two consecutive days. Consecutively, shungite was topically applied on the dorsal side of the mice for 7 days. First, we found significant improvements in the skin parameters of the shungite-treated groups revealed by the reduction in roughness, pigmentation, and wrinkle measurement. Second, the immunokine profiling in mouse serum and skin lysates showed a reduction in the proinflammatory response in the shungite-treated groups. Accordingly, the redox profile of shungite-treated groups showed counterbalance of ROS/RNS and superoxide levels in serum and skin lysates. Last, we have confirmed the involvement of Nrf2- and MAPK-mediated oxidative stress pathways in the antioxidant mechanism of shungite. Collectively, the results clearly show that shungite has an antioxidant and anti-inflammatory action against UVB-induced skin damage in hairless mice