bluuebunny/crossref_metadata_2025_split huggingface dataset:
Review of Morphology Dependent Charge Carrier Mobility in MEH‐PPV
Authors: Inigo A. R. , Huang Y. F. , White J. D. , Huang Y. S. , Fann W. S. , Peng K. Y. , Chen S. A. 
Published: May 2015

AbstractCharge carrier mobility in poly(2‐methoxy,5(2′‐ethyl‐hexyloxy)‐p‐phenylene vinylene) (MEH‐PPV) films were measured as a function of temperature and electric field parallel and perpendicular to the substrate for devices prepared from different solvents and under different processing conditions. Bulk structural morphology was characterized by various X‐ray diffraction measurements such as wide angle, small angle and X‐ray reflection. Surface morphology was characterized using various scanning probe microscopic techniques. Mobilities were found to follow Gaussian disorder model (GDM) and to be highly anisotropic not only depending on the solvents used but also on the film preparation method such as spin‐coating or drop‐casting. While no direct correlation was found between charge carrier mobility and photoluminescence, charge transport parameters were correlated with structural morphology.
1H NMR Spectroscopic Study of the Solution Structure of a Conjugated Polymer
Authors: Rahman M. Habibur , Chen Hsin‐Lung , Chen Show‐An , Chu Peter P. J. 
Published: May 2015

AbstractThe structure of poly[2‐methoxy‐5‐(2′‐ethylhexyloxy)‐1,4‐phenylenevinylene] (MEH‐PPV) solutions with a number of common deuterated organic solvents was studied by means of 1H NMR spectroscopy. The resonance bands of the polymer backbone protons appear at much lower frequencies in CDCl3 compared to their positions in aromatic solvents. This has been attributed to the π‐π self‐stacking interaction of the polymer segments in the aliphatic solvent, which is replaced by a polymer‐solvent π‐π interaction in the aromatic solvents. In mixed solvent systems with an aliphatic solvent component and an aromatic one, the intensities of the polymer resonances pass through a maximum at intermediate solvent compositions. This has been attributed to the minimum aggregation tendency of the polymer at these solvent compositions. The results suggest that a mixed solvent system constituting an aliphatic component and an aromatic component might be a choice for casting films of hairy‐rod type conjugated polymers if minimization of aggregate domains in the films is desired.
A Single Molecule FRET Study of Formation of RNA Polymerase II Elongation Complex on Passivated Surface
Authors: Lin Yen‐Chen , Lin Bo‐Lin , Setiawan Tommy , Chang Chia‐Chi , Yen Chi‐Fu , Chang Wei‐Hau 
Published: May 2015

AbstractRNA polymerase II (pol II) is an essential enzyme that transcribes protein‐coding genes. It is of rudimentary and medical importance to understand the mechanisms of pol II transcription. By passivating fused‐silica surface with biologically‐friendly polyethylene glycol (PEG), we immobilized a RNA‐primed double‐stranded DNA, termed DNA/RNA scaffold, to build a single molecule transcription assay using FRET (fluorescence resonance energy transfer) signals from a donor on DNA and an acceptor on RNA as readouts, which allowed us to monitor how pol II assembles with the DNA/RNA scaffold with a total internal reflection fluorescence microscope. Here, our single molecular FRET assay shows that the DNA/RNA scaffold assumes heterogeneous conformations in the absence of pol II but retains a unique conformation in the presence of pol II, indicated by a single‐valued FRET value consistent with the RNA engaging in the pol II's RNA exit channel. Our study of pol II interacting with DNA/RNA offers an example for demonstrating that the single FRET assay is powerful in the following aspects: (1) it improves the spatial resolution of a few hundreds of nanometers, limited by optical diffraction on an ordinary fluorescence microscope, to nanometers; (2) it provides dynamical information with temporal resolution set by fluorescence microscopy instrumentation; and (3) it allows sorting of single molecules to reveal the heterogeneity, averaged out by bulk measurements. Such a single molecule FRET transcription assay can be readily extended to visualize nascent RNA extension in real‐time with the supply of NTPs, or be applied to dissect the architecture of various kinds of RNA polymerases, including pol I and pol III, the relatives of pol II.
Synthesis of Silver Nanoprisms and Nanodiscs an Applications in Fluorescence Blinking Suppression
Authors: Yu Pyng , Huang Jane , Yuan Chi‐Tsu , Tang Jau 
Published: May 2015

AbstractIn this work we investigated the influence of reagents in the synthesis of triangular silver nanoprisms through direct chemical reduction. We identified the chemical role of each reagent, i.e. H2O2, poly(vinylpyrrolidone) (PVP) and NaBH4, by systematically varying one reagent concentration while keeping the concentration of other reagents constant. We also discuss the applications of nanoprisms in blinking suppression of single semiconductor quantum dots. In addition, we also investigated the synthesis of silver nanodiscs through the reconstruction of triangular nanoprisms using halide ions. The results from different halide ions presented the different face‐selective etching rates on the well‐identified facet in the silver nanoprism.
Facile and Efficient Amination of Organic Halides Catalyzed by Copper Sulfate in PEG1000‐DIL/Methylcyclohexane Temperature‐Dependent Biphasic System
Authors: Hu Yu‐Lin , Wang Peng‐Cheng , Chen Tian , Lu Ming 
Published: May 2015

AbstractA simple, efficient, and environmentally friendly procedure for the amination of organic halides catalyzed by CuSO4·5H2O in PEG1000‐DIL/methylcyclohexane temperature‐dependent biphasic system is described. The product can be easily isolated by a simple decantation, and the catalytic system can be recycled and reused without loss of catalytic activity.
UV Spectrophotometric Determination of Cu(II) in Synthetic Mixture and Water Samples
Authors: Lutfullah  , Sharma Saurabh , Rahman Nafisur , Azmi Syed Najmul Hejaz , Iqbal Bashir , Amburk Maisa Ismail Bilal Bait , Al Barwani Zuweina Masoud Hilal 
Published: May 2015

AbstractA new and novel UV spectrophotometric method has been developed for the determination Cu(II) in synthetic mixture and water samples. The method is based on complex formation of Cu(II) with cefixime immediately in 1,4‐dioxan‐distilled water medium at room temperature. The complex showed maximum absorption wavelength at 336 nm. Beer's law is obeyed in the concentration range of 1.015‐8.122 μg mL−1 (Linear regression: A = 1.59 × 10−3 + 1.305 × 10−1 C) with apparent molar absorptivity (8.29 × 103 L mol−1cm−1) and Sandell's sensitivity (0.008 μg/cm2/0.001 absorbance unit). The limits of detection and quantitation for the developed method are 3.19 × 10−2 and 9.65 × 10−2 μg mL−1, respectively. Interferences due to Mn(II), Ca(II), Mg(II), Cd(II), Al(III), Pb(II), Zn(II), Fe(II), Fe(III), Ni(II), Cr(III), Hg(II) and As(III) was investigated. Nine cations do not interfere in the determination of Cu(II). Proposed method was successfully applied to the determination of Cu(II) in synthetic mixture, sea and well water samples.
Interaction of Di‐ and Triorganotin(IV) Compounds with Carboxylate Ligand: Synthesis, Spectral Characterization, Semi‐Empirical Study and In Vitro Antimicrobial Activities
Authors: Shahzadi Saira , Ali Saqib , Shahid Khadija , Yousaf Muhammad , Sharma Saroj K. , Qanungo Kushal 
Published: May 2015

AbstractDi‐ and triorganotin(IV) complexes with the general formulae RnSnL4‐n, where R = Me, n‐Bu, Ph and L = 2‐[(2′‐methylphenylamido)]benzoic acid have been synthesized by the reaction of triethylammonium salt of 2‐[(2′‐methylphenylamido)]benzoic acid with di‐ and triorganotin chloride in dry toluene. All the synthesized complexes were characterized by elemental analysis, FT‐IR, multinuclear (1H, 13C, 119Sn) NMR, mass spectrometry and semi‐empirical study to assess the binding mode of 2‐[(2′‐methylphenylamido)]benzoic acid. The diorganotin(IV) derivatives are assessed to adopt distorted octahedral and triorganotin(IV) have linear polymeric trigonal bipyramidal structures in which 2‐[(2′‐methylphenylamido)]benzoic acid is a monoanionic bidentate, coordinating through C(O)O group. This coordination behaviour is also confirmed by semi‐empirical study. The isotopic effect of tin was studied by comparison of experimental data with the simulated isotopic pattern using the Chemtool software package. The insecticidal, antileshmanial, antibacterial, antifungal and cytotoxicity of the synthesized compounds are also reported. Some complexes exhibit good activities comparable to that of standard drugs. Furthermore, triorganotin(IV) derivatives exhibit significantly better activities than the diorganotin(IV) derivatives and have a potential to be used as drug.
Complexes of Cu(II) and Ni(II) with Bis(Phenylthiosemicarbazone): Synthesis, Spectral, EPR and in Vitro ‐ Antibacterial and Antioxidant Activity
Authors: Rao Y. Subba , Prathima B. , Reddy S. Adinarayana , Madhavi K. , Reddy A. Varada 
Published: May 2015

AbstractThe synthesis of Cu(II) and Ni(II) complexes with 2,6‐diacetylpyridine bis(4‐phenyl‐3‐thiosemicarbazone) (L) ligand have been reported. The ligand was characterized by elemental analysis and spectral (IR and 1H NMR) studies and its complexes were characterized by electronic, UV/VIS, EPR and IR studies. The room‐temperature EPR spectrum of Cu(II) complex was recorded and the analysis of its spectrum gave {g} tensor with g1 = 2.25, g2 = 2.15, and g3 = 2.07 which were of distorted octahedral structure. The electronic spectrum of Ni(II) complex indicated the octahedral geometry around the Ni(II) ion. Their antibacterial activities were evaluated by the diameter of zone of inhibition (mm) against four bacteria such as B. subtilis, S. aureus, E. coli and K. pneumonia. The ligand and the 6‐coordinate Ni(II) complex did not inhibit the growth of the test organisms, while the Cu(II) complex showed good antibacterial activity than parent ligand against the same bacteria. The free ligand and its metal complexes have been tested for in vitro ‐ antioxidant activity by reduction of 1,1‐diphenyl‐2‐picryl hydrazyl (DPPH) and iron induced lipid peroxidation using rat brain homogenate. The ligand exhibited potent in vitro ‐ antioxidant activity than its Ni(II) and Cu(II)complexes.
Silica Chloride Catalysed One‐pot Synthesis of 13‐Aryl‐indeno[1,2‐b]naphtha[1,2‐e]pyran‐12(13H)‐ones under Solvent‐free Conditions
Authors: Wu Li‐Qiang , Yang Li‐Min , Wang Xiao , Yan Fu‐Lin 
Published: May 2015

AbstractA simple and facile synthesis of 13‐aryl‐indeno[1,2‐b]naphtha[1,2‐e]pyran‐12(13H)‐ones has been accomplished by the one‐pot condensation of β‐naphthol, aldehydes, and 2H‐indene‐1,3‐dione under solvent‐free conditions in the presence of the heterogeneous catalyst silica chloride.
Chemical Composition and Bioactivity of Essential Oil of Seed and Leaf from Alpinia speciosa Grown in Taiwan
Authors: Ho Jiau‐Ching 
Published: May 2015

AbstractThe essential oil, methanolic and aqueous extracts of the seeds and leaves of Alpinia speciosa (Wendl.) K. Schum. (Zingiberaceae) were assayed for their mushroom tyrosinase inhibition, larvicidal effect, antioxidant property and antimicrobial activity. The main components of the seeds were camphor, sabinene, (Z)‐β‐ocimene, 1,8‐cineole, terpinen‐4‐ol and α‐pinene, while the leaves contains camphor, sabinene, γ‐terpinene, terpinen‐4‐ol and α‐terpineol. The seed and leaf oil exhibited concentration‐dependent inhibition of mushroom tyrosinase, giving 74 and 81% inhibition at 1000 ppm, respectively. The seed oil exhibits the mosquito larvicidal activity with 2 h and 24 h LC50 value of 125 and 87 ppm, respectively, whereas the leaf oil shows larvicidal activity with 2 h and 24 h LC50 value of 64 and 32 ppm, respectively. The methanolic and aqueous extracts of A. speciosa show remarkable antioxidant effect. This activity can be attributed to the presence of the phenolic compounds. The essential oil of A. speciosa exhibits a strong broad‐spectrum antimicrobial activity against all test organisms. The seeds and leaves of A. speciosa could be considered as a natural tyrosinase inhibition, mosquito larvicidal, antioxidant and antimicrobial source.
Highly Regioselective Oxybromination in an Aqueous System Using SBA‐15 Supported Sulfated Zirconia Catalyst
Authors: Chen Ai‐Jan , Chen Xiao‐Rong , Mou Chung‐Yuan 
Published: May 2015

AbstractSBA‐15 supported sulfated zirconia (SZ) catalysts were employed in many acid‐catalysis of reactions under mild condition because it is a strong solid acid with various Lewis and Brønsted acid sites. An oxybromination of aromatic substrates using hydrogen peroxide and ammonium bromide in the aqueous phase under mild temperature and near‐neutral pH condition over SZ was achieved. A good to excellent para‐selectivity was observed. The mesoporous silica SBA‐15 supported SZ possessed higher catalytic activity than self‐supported SZ because of larger surface area and pore size. The effect of the calcinations temperature was also investigated. The good catalytic performance of the SZ/SBA‐15 materials was attributed to high degree of dispersion of sulfate groups to give sulfated silica‐zirconia of (1) very good redox property and (2) high strength and high density of acid sites. The SZ/SBA‐15 catalyst may be re‐used several times without substantial loss of activity.
Analysis of Copper in an Aqueous Solution by Ion‐Exchange Concentrator and Laser‐Induced Breakdown Spectroscopy
Authors: Kim Taesam , Ricchia Michael L. , Lin Chhiu‐Tsu 
Published: May 2015

AbstractLaser‐induced breakdown spectroscopy in composition analysis of materials has many advantages over other analytical methods. Its simple‐or‐no sampling procedure is a key advantage. The LIBS has been applied to liquid samples, although direct analysis of liquids is difficult because of weak plasma generation. An ion exchange membrane is used in this work to develop a real time monitoring method of metal ions in water. The chelating‐resin based filter membrane was used to capture and concentrate copper ions from water. The samples were filtered under reduced pressure for faster filtration. The captured copper ions on the membrane were analyzed by LIBS. A series of copper solutions and mixtures were examined to establish the proper analytical conditions. The plasma emission intensity of copper generated from the thin layer of the membrane was investigated to determine the spectroscopic parameters for a practical real‐time water monitoring. The copper ion collected on the membrane can be free of matrix effect from other ions in the original samples, and has provided the consistent analytical results in the mg/L concentration range. The laser power of each ablating pulse is very critical to obtain a proper analytical dynamic range, especially when the copper captured layer is thicker than the depth of one pulse laser can ablate. Tap water was used to analyze and evaluate the feasibility of this method. The amount of copper in the tap water was shown to depend on the retention time of water in copper pipes of the building pluming system.
The Use Ionic Liquid as the Eluent Additive for HPLC Separation of Ionic Dyes
Authors: Chen Hsiu‐Liang , Wei Guor‐Tzo 
Published: May 2015

AbstractReversed‐phase HPLC separation of ionic dyes (methylene blue, neutral red, methyl orange, and acid orange) with 1‐alkyl‐3‐methylimidazolium ionic liquids as the eluent additives was studied. The addition of ionic liquid to the eluent affects the resolution, peak shape and reproducibility of the retention of ionic solutes. The use of ionic liquids as the additives facilitates the separation of ionic dyes with a reversed‐phase HPLC. Baseline‐resolved separation of these dyes was achieved in 12 minutes when the mobile phase of acetonitrile‐water (28:72,v/v) contained 0.3‐2.0% (v/v) [emim][BF4]. The detection limits for the four dyes ranged from 4.45 to 10.0 μg/L for an injection volume of 20 μL. Apparently, ionic liquid is an effective mobile phase additive for the separation of ionic dyes in reversed‐phase HPLC separation.
Cloning and Expression of Bioactive Human Granulocyte Colony Stimulating Factor in Pichia Pastoris
Authors: Chien Su‐Fang 
Published: May 2015

AbstractFor over ten years, recombinant human Granulocyte Colony Stimulating Factor (hG‐CSF) has been broadly used in clinical applications. Many sources of G‐CSF have the disadvantage of being in intracellular or aggregated form. In this paper, we report the molecular cloning and gene expression in the protease resistant strain of yeast (SMD1168). More than 90% of the G‐CSF protein is in secreted form and about 100 mg of the biologic active human G‐CSF can be obtained from two liters of bioreactor. The recombinant G‐CSF promotes HL‐60 (Human promyelocytic cell) cell proliferation and elevates the mitochondrial succinate dehydrogenase activity. The dose effects of rG‐CSF on cell proliferation responses to the total numbers of the receptors on the cell surfaces have been investigated and the quantitative results were obtained. The receptors are saturated by G‐CSF at the 50 ng/mL for 1 × 105cells. The prompt increasing in the succinate dehydrogenas activity was also observed. This effect is comparable to that from the commercial source. We have successfully cloned and expressed a bioactive rhG‐CSF from the medium in the Pichia pastoris system. This specific product is expected to meet the clinical applications in the treatments of neutropenia, acute cerebral ischemia and other neuro‐degenerated diseases.
Ligands Coordinated with Cu(II) Complexes in Rare Anti‐Syn 2,2′‐Dipyridylamine and Acetate‐Bridged Forms: Preparations, Crystal Structures, Hydrogen Bonds and Magnetic Properties
Authors: Chung Yun‐Ho , Lin Hsin‐Huang , Lee Chin‐Jhan , Liou Shyh‐Yeon 
Published: May 2015

AbstractThe Hdpa (2,2′‐dipyridylamine) ligand can be bonded with metal ions respectively in the anti‐anti, anti‐syn and syn‐syn form, in which the anti‐syn form is rare in the studies. Interestingly, the Hdpa ligand in the mononuclear copper complex [Cu(Acac)2(Hdpa)2], 1 (Acac = Acetylacetone) prepared by this experiment is in the rare anti‐syn form. The six‐coordination of Cu(II) atom with two nitrogen atoms are from Hdpa and four oxygens atoms are from Acac. The Crystallographic data show the monoclinic space group P2(1)/n with a = 8.5285(7)Å, b = 9.6900(8)Å, c = 17.9757(15)Å, β = 99.019(2)° and Z = 2.The Hdpa ligand in the zig‐zag chain copper complex [Cu2(μ‐CH3CO2)(NCS)2(Hdpa)2]n, 2 prepared by this experiment is in the usual syn‐syn form. But in the long chain, CH3CO2− (acetate group) and NCS−(thiocyanate) take turns acting as a bridging group, and the bridging carboxylate ligand is in the rare anti‐syn form. The geometry at each copper(II) ion is best described as a distorted(4 + 1) square‐base pyramid. The Crystallographic data show the monoclinic space group P2(1)/c with a = 10.257(3)Å, b = 15.533(4)Å, c = 18.873(5)Å, β = 101.570(4) ° and Z = 4.The crystal of the complex [Cu(dpk·H2O)2](SCN)2·2H2O, 3 (dpk = di‐2‐pyridyl ketone) was announced in the recognized literature. It was proved that the H2O molecule played the role of the bridging bond in the analogue complex [Cu(dpk·H2O)2](X)2·nH2O. With the presence of the dpk·H2O and thiocyanate SCN−1 groups, the complex 3 constitutes the structure of hydrogen bonds with the 2D network of four different forms, such as OH···O(two forms), OH···N and OH···S. This is a pretty extraordinary phenomenon. The Crystallographic data show the monoclinic space group P2(1)/c with a = 7.9174(6)Å, b = 9.2398(7)Å, c = 9.4321(7)Å, β = 95.462(1)° and Z = 1.Complex 1 and complex 3 are Cu (II) mononuclear. This is indicative of the typical paramagnetic behavior of unpaired electrons. We fit the data of the complex 2 by using the equation for S = 1/2 ferromagnetic /antiferromagnetic systems. The best fit parameters for the data are g = 2.03, α = 4.85, J1 = −0.93 cm−1, J2 = 4.52 cm−1 and R = 1.5 × 10−5.
Trigonal Bipyramidal {Fe(NO)}7 Complex [(NO)Fe(SC9H6N)2] Containing an Equatorial Nitrosyl Ligand: The Critical Role of Chelating Ligands in Regulating the Geometry and Transformation of Mononitrosyl Iron Complex (MNIC)
Authors: Lu Tsai‐Te , Yang Li‐Bo , Liaw Wen‐Feng 
Published: May 2015

AbstractTrigonal bipyramidal {Fe(NO)}7 complex [(NO)Fe(SC9H6N)2] (2) with NO ligand occupying equatorial position, obtained from nitrosylation of complex [(Cl)Fe(SC9H6N)2]− (1) accompanied by elimination of [Cl]−, was characterized by IR, UV‐Vis, EPR, SQUID and single‐crystal X‐ray diffraction. Compared to the S = 3/2 ground state displayed by the trigonal bipyramidal complex [Et4N][(ON)Fe(N‐(CH2CH2S)3)], the chelating ligands ([SC9H6N]−) play a key role in modulating the position of exogenous NO ligand and controlling the spin state of complex 2 (S = 1/2). In contrast to nitrosylation of [Fe(NO)(SPh)3]− MNIC yielding [Fe(NO)2(SPh)2]− DNIC, the inertness of complex 2 toward NO(g) was observed. Reaction of [NO][BF4] and complex 2 in a 1:1 stoichiometry led to the formation of homodinuclear {Fe(NO)}7‐{Fe(NO)}9 complex [(ON)Fe(‐SC9H6N)2Fe(NO)2][BF4] (3) characterized by IR, UV‐vis, 1H NMR and single‐crystal X‐ray diffraction. Antiferromagnetic coupling between the S = 1/2 {Fe(NO)}7 [S2Fe(NO)2] core and the S = 1/2 {Fe(NO)}7 [(NO)FeS2N2] core may account for the diamagnetism and the EPR silence of complex 3. This study provides the evidence that the geometric and electronic structures of {Fe(NO)}7 MNICs modulated by the coordination environment of iron center determines the nitrosylation products.
Crystal Structure and Phase Transitions of Gd(CO3)OH Studied by Synchrotron Powder Diffraction
Authors: Sheu Hwo‐Shuenn , Shih Wei‐Ju , Chuang Wei‐Tsung , Li I‐Fang , Yeh Chen‐Sheng 
Published: May 2015

AbstractThe crystal structure of Gd(CO3)OH was solved using synchrotron powder X‐ray diffraction. Gd(CO3)OH was known to exist in a form Gd2O(CO3)2·H2O and its powder pattern has been listed in JCPDF (#430604) for decades, but the crystal structure has not yet been elucidated. The crystal structure is solved with simulated annealing and the DASH program. The final Rietveld refinement converged to Rwp =6.28%, Rp = 4.47%and χ2 = 1.348, using the GSAS program. Gd(CO3)OH crystallizes in orthorhombic system with lattice parameters a = 7.08109(9), b = 4.88436(7), c = 8.45010(13)Å and space group P nma. Gd(CO3)OH forms a three‐dimensional framework with an eight‐membered ring, a one‐dimensional channel and OH− in the cavity. XANES of Gd LIII‐edge indicates that the oxidation state of Gd is 3+. Two phase transitions of Gd(CO3)OH were found at 500 and 650 °C to yield Gd2O2CO3 and Gd2O3 respectively.
Assembly Characteristics of Gold Nanoparticles and Nanorods in Ionic Surfactant Solutions
Authors: Tu Kuan‐Ju , Chen Shih‐Yeh , Deng Jin‐Pei 
Published: May 2015

AbstractGold nanoparticles (NPs) and nanorods (NRs) were synthesized by chemical reduction in the aqueous micellar solution of ionic surfactants. Their surfaces were subsequently modified by cysteine. In the cationic cetyltrimethylammonium bromide (CTAB) solution, the linear cross‐assembly of gold NRs with NPs in alternate order was observed and could be related to the size‐dependent densities of their surface charges. The irregular aggregation of gold NRs (and NPs) appeared in the anionic sodium dodecyl sulfate (SDS) solution. Micellar electrokinetic capillary chromatography (MEKC) showed that cysteine‐binding gold NRs resulted in the decrease of their negative surface charge in the SDS solution. Experimental results indicated that the ionic surfactant which stabilized both gold NPs and NRs has the extraordinary effect on not only the location of the surface modification but also the interaction of the assembly for these NPs and NRs. Mechanism on the assembly of gold NPs and NRs in the ionic solutions will be discussed.