Lymphokines

Llen, Jane W.S.x,Lau, Johnson Y.N.,Lal, Ching Lung Medical Publications Korea 1991 Medical Progress Vol.13 No.3

The Permanent Pacemaker in Therapy : The Taiwan Experience

Llen, Wen-Pin Medical Publications Korea 1991 Medical Progress Vol.13 No.3

해외입양 사후관리 서비스의 문제점과 그 개선에 관한 연구

고혜연 ( He Llen Ko ),임영식 ( Young Sik Lim ) 한국청소년복지학회 2008 청소년복지연구 Vol.10 No.1

First-Principles Modeling of the Polycyclic Aromatic Hydrocarbons Reduction

Boukhvalov, D. W.,Feng, X.,Mü,llen, K. American Chemical Society 2011 The Journal of Physical Chemistry Part C Vol.115 No.32

<P>Density functional theory modeling of the reduction of realistic nanographene molecules (C<SUB>42</SUB>H<SUB>18</SUB>, C<SUB>48</SUB>H<SUB>18</SUB>, and C<SUB>60</SUB>H<SUB>24</SUB>) by molecular hydrogen evidence of the presence of limits in the hydrogenation process. These limits caused the contentions between three-fold symmetry of polycyclic aromatic hydrocarbon molecules and two-fold symmetry of adsorbed hydrogen pairs. Increase in the binding energy between nanographenes during reduction is also discussed as a possible cause of the experimentally observed limited hydrogenation of studied nanographenes.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/jpccck/2011/jpccck.2011.115.issue-32/jp2024928/production/images/medium/jp-2011-024928_0002.gif'></P>

Conjugated Triphenylene Polymers for Blue OLED Devices

Saleh, Moussa,Park, Young-Seo,Baumgarten, Martin,Kim, Jang-Joo,Mü,llen, Klaus WILEY-VCH Verlag 2009 Macromolecular Rapid Communications Vol.30 No.14

<P>Three polytriphenylene derivatives with phenyl and alkyl groups as side chains have been tested as blue light emitters. The best performance in terms of turn-on voltage and luminance efficiencies was obtained for poly(2-heptyl-3-(4-octylphenyl)-1,4-diphenyl-6,11-triphenylenyl-1,4-benzene) (1), which was additionally blended with an electron-transporting and a hole-injection material in the device, and had an onset of 4.6 V and reached 0.73 cd · A<SUP>−1</SUP>.</P><P> <img src='wiley_img/10221336-2009-30-14-MARC200900332-gra001.gif' alt='wiley_img/10221336-2009-30-14-MARC200900332-gra001'> </P> <B>Graphic Abstract</B> <P>Blue-emitting conjugated triphenylene-based polymers have been synthesized using the microwave-assisted Suzuki– Miyaura and Yamamoto polycondensation reactions. All polymers showed deep- blue emission in films with PL maxima around 430 nm. The device performance in terms of luminescence efficiency, power efficiency, turn-on voltage, and electroluminescence present all polymers as good candidates for polymer organic light emitting diodes. <img src='wiley_img/10221336-2009-30-14-MARC200900332-content.gif' alt='wiley_img/10221336-2009-30-14-MARC200900332-content'> </P>

Liquid Crystalline Ordering and Charge Transport in Semiconducting Materials

Pisula, Wojciech,Zorn, Matthias,Chang, Ji Young,Mü,llen, Klaus,Zentel, Rudolf WILEY-VCH Verlag 2009 Macromolecular Rapid Communications Vol.30 No.14

<P>Organic semiconducting materials offer the advantage of solution processability into flexible films. In most cases, their drawback is based on their low charge carrier mobility, which is directly related to the packing of the molecules both on local (amorphous versus crystalline) and on macroscopic (grain boundaries) length scales. Liquid crystalline ordering offers the possibility of circumventing this problem. An advanced concept comprises: i) the application of materials with different liquid crystalline phases, ii) the orientation of a low viscosity high temperature phase, and, iii) the transfer of the macroscopic orientation during cooling to a highly ordered (at best, crystalline-like) phase at room temperature. At the same time, the desired orientation for the application (OLED or field-effect transistor) can be obtained. This review presents the use of molecules with discotic, calamitic and sanidic phases and discusses the sensitivity of the phases with regard to defects depending on the dimensionality of the ordered structure (columns: 1D, smectic layers and sanidic phases: 2D). It presents ways to systematically improve charge carrier mobility by proper variation of the electronic and steric (packing) structure of the constituting molecules and to reach charge carrier mobilities that are close to and comparable to amorphous silicon, with values of 0.1 to 0.7 cm<SUP>2</SUP> · V<SUP>−1</SUP> · s<SUP>−1</SUP>. In this context, the significance of cross-linking to stabilize the orientation and liquid crystalline behavior of inorganic/organic hybrids is also discussed.</P><P> <img src='wiley_img/10221336-2009-30-14-MARC200900251-gra001.gif' alt='wiley_img/10221336-2009-30-14-MARC200900251-gra001'> </P> <B>Graphic Abstract</B> <P>Liquid crystalline ordering offers the possibility of improving charge carrier mobility. This review discusses the potential of LC-mediated ordering of rod- and disc-like objects in pure organic and organic-inorganic hybrid structures. <img src='wiley_img/10221336-2009-30-14-MARC200900251-content.gif' alt='wiley_img/10221336-2009-30-14-MARC200900251-content'> </P>

Self-Assembly Behavior of Alkylated Isophthalic Acids Revisited: Concentration in Control and Guest-Induced Phase Transformation

Park, Kwang-Won,Adisoejoso, Jinne,Plas, Jan,Hong, Jongin,Mü,llen, Klaus,De Feyter, Steven American Chemical Society 2014 Langmuir Vol.30 No.50

<P>The engineering of two-dimensional crystals by physisorption-based molecular self-assembly at the liquid–solid interface is a powerful method to functionalize and nanostructure surfaces. The formation of high-symmetry networks from low-symmetry building blocks is a particularly important target. Alkylated isophthalic acid (ISA) derivatives are early test systems, and it was demonstrated that to produce a so-called porous hexagonal packing of plane group <I>p</I>6, i.e., a regular array of nanowells, either short alkyl chains or the introduction of bulky groups within the chains were mandatory. After all, the van der Waals interactions between adjacent alkyl chains or alkyl chains and the surface would dominate the ideal hydrogen bonding between the carboxyl groups, and therefore, a close-packed lamella structure (plane group <I>p</I>2) was uniquely observed. In this contribution, we show two versatile approaches to circumvent this problem, which are based on well-known principles: the “concentration in control” and the “guest-induced transformation” methods. The successful application of these methods makes ISA suitable building blocks to engineer a porous pattern, in which the distance between the pores can be tuned with nanometer precision.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/langd5/2014/langd5.2014.30.issue-50/la5040849/production/images/medium/la-2014-040849_0006.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/la5040849'>ACS Electronic Supporting Info</A></P>

Accurate Diffusion Coefficients of Organosoluble Reference Dyes in Organic Media Measured by Dual-Focus Fluorescence Correlation Spectroscopy

Goossens, Karel,Prior, Mira,Pacheco, Victor,Willbold, Dieter,Mü,llen, Klaus,Enderlein, Jö,rg,Hofkens, Johan,Gregor, Ingo American Chemical Society 2015 ACS NANO Vol.9 No.7

<P>Dual-focus fluorescence correlation spectroscopy (2fFCS) is a versatile method to determine accurate diffusion coefficients of fluorescent species in an absolute, reference-free manner. Whereas (either classical or dual-focus) FCS has been employed primarily in the life sciences and thus in aqueous environments, it is increasingly being used in materials chemistry, as well. These measurements are often performed in nonaqueous media such as organic solvents. However, the diffusion coefficients of reference dyes in organic solvents are not readily available. For this reason we determined the translational diffusion coefficients of several commercially available organosoluble fluorescent dyes by means of 2fFCS. The selected dyes and organic solvents span the visible spectrum and a broad range of refractive indices, respectively. The diffusion coefficients can be used as absolute reference values for the calibration of experimental FCS setups, allowing quantitative measurements to be performed. We show that reliable information about the hydrodynamic dimensions of the fluorescent species (including noncommercial compounds) within organic media can be extracted from the 2fFCS data.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/ancac3/2015/ancac3.2015.9.issue-7/acsnano.5b02371/production/images/medium/nn-2015-02371p_0006.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/nn5b02371'>ACS Electronic Supporting Info</A></P>

The impact of charge defects and resonance enhancement on the two-photon absorption activity of spirofluorene and ladder-type pentaphenylene derivatives

Cho, Namchul,Zhou, Gang,Kamada, Kenji,Kim, Ran Hee,Ohta, Koji,Jin, Sung-Ho,Mü,llen, Klaus,Lee, Kwang-Sup The Royal Society of Chemistry 2012 Journal of materials chemistry Vol.22 No.1

<p>Novel two-photon absorption (TPA) chromophores that contain spirofluorene and ladder-type pentaphenylenes (LPPs) as π-centres with diarylamine groups as electron donors (D) in the D–π–D arrangement are prepared. The spirofluorenes with different donors at the both terminals exhibit TPA activity increase as the donor strength increases (from <I>N</I>-ethylcarbazoyl <B>1</B>, triphenylamino <B>2</B>, to <I>N</I>,<I>N</I>-dibutylaminophenyl <B>3</B>). Compared to the spirofluorene derivatives, the LPP derivatives show the larger TPA efficiency due to better coplanarity throughout the molecule. As the LPP unit added from single (<B>4</B>), double (<B>5</B>), to triple (<B>6</B>), the increment of the TPA cross-section exceeds the one-fold of a LPP unit, which can be attributed to the cooperative enhancement of the TPA cross-section (<I>σ</I><SUB>2</SUB>) between the LPP units. We have also explored the effect of introducing charge defects and examined the resonance enhancement by chemical oxidation on the TPA properties of LPP derivatives <B>4</B> and <B>5</B>. Nearly an order of magnitude enhancement was found in the TPA cross-section of dye <B>4</B>, which was interpreted as the role of charge transfer from LPP π-centre to the cationic diarylamine end groups.</p> <P>Graphic Abstract</P><P>We have demonstrated that the unique structural properties of a ladder-type pentaphenylene (LPP) moiety and its cationic states lead to a strong two-photon absorption (TPA) response. <img src='http://pubs.rsc.org/ej/JM/2011/c1jm13481g/c1jm13481g-ga.gif'> </P>

Saline extract of Portulaca elatior leaves with photoprotective and antioxidant activities does not show acute oral and dermal toxicity in mice

da Silva Suéllen Pedrosa,da Costa Clarice Barbosa Lucena,de Freitas Anderson Felipe Soares,da Silva José Dayvid Ferreira,Costa Wêndeo Kennedy,da Silva Wênio Sandoval Filho Lima,Machado Janaina Carla B 한국독성학회 2023 Toxicological Research Vol.39 No.2

The present study aimed to evaluate saline extracts from the leaves (LE) and stem (SE) of Portulaca elatior in relation to their phytochemical composition and photoprotective and antioxidant effects, as well as to evaluate the toxicity of the leaf extract. The extracts were characterized for protein concentration and phenol and flavonoid contents, as well as for thin layer chromatography (TLC) and high-performance liquid chromatography (HPLC) profiles. Total antioxidant capacity and DPPH and ABTS+ scavenging activities were determined. In the photoprotective activity assay, the sun protection factor (SPF) was calculated. The toxicity evaluation of LE included in vitro hemolytic assay and in vivo oral and dermal acute toxicity assays in Swiss mice. LE showed the highest protein, phenol, and flavonoid (8.79 mg/mL, 323.46 mg GAE/g, and 101.96 QE/g, respectively). TLC revealed the presence of flavonoids, reducing sugars, terpenes, and steroids in both extracts. In HPLC profiles, LE contained flavonoids, while SE contained flavonoids and ellagic tannins. The antioxidant activity assays showed the lowest IC50 values (34.15–413.3 μg/mL) for LE, which presented relevant SPF (> 6) at 50 and 100 μg/mL. LE demonstrated low hemolytic capacity, and no signs of intoxication were observed in mice treated orally or topically at 1000 mg/kg. However, at 2000 mg/kg, an increase in the mean corpuscular volume of erythrocytes and a reduction in lymphocytes were observed; animals treated topically with 2000 mg/kg displayed scratching behavior during the first hour of observation and showed edema and erythema that regressed after six days. In conclusion, LE did not present acute oral or dermal toxicity in Swiss mice at a dose of 1000 mg/kg and showed slight toxicity in animals treated with 2000 mg/kg.