bluuebunny/crossref_metadata_2025_split huggingface dataset:
Benefit assessment of therapeutic products: the Centers for Education and Research on Therapeutics
Authors: Califf Robert M. ,   for the CERTs Benefit Assessment Workshop Participants
Published: February 2006

AbstractThe ability to manage risk depends critically on an understanding of the degree to which a known risk is balanced by the probability of a clinical benefit. Despite the massive emphasis on risk and risk management in the past few years and the long‐term focus on defining benefit in the regulatory system, considerable uncertainty remains about the methods of defining benefit and how to operationalize this knowledge. In this ‘think tank,’ part of a larger series on risk management, issues were divided into those that can be identified before a study is initiated, those that commonly arise after a study is completed, biomarkers and surrogates, use of benefit findings in defining quality and performance indicators, implementation of findings into health systems and formularies, and methods of comparative trials. Key categories for the establishment of a research agenda to fill in gaps in our understanding of assessing benefit were developed by the group. Copyright © 2006 John Wiley & Sons, Ltd.
Thermal properties and non‐isothermal crystallization behavior of biodegradable poly(p‐dioxanone)/poly(vinyl alcohol) blends
Authors: Zhou Zhi‐Xuan , Wang Xiu‐Li , Wang Yu‐Zhong , Yang Ke‐Ke , Chen Si‐Chong , Wu Gang , Li Jun 
Published: March 2006

AbstractBlends of two biodegradable semicrystalline polymers, poly(p‐dioxanone) (PPDO) and poly(vinyl alcohol) (PVA) were prepared with different compositions. The thermal stability, phase morphology and thermal behavior of the blends were studied by using thermogravimetric analysis (TGA), scanning electron microscopy (SEM) and differential scanning calorimetry (DSC). From the TGA data, it can be seen that the addition of PVA improves the thermal stability of PPDO. DSC analysis showed that the glass transition temperature (Tg) and the melting temperature (Tm) of PPDO in the blends were nearly constant and equal to the values for neat PPDO, thus suggesting that PPDO and PVA are immiscible. It was found from the SEM images that the blends were phase‐separated, which was consistent with the DSC results. Additionally, non‐isothermal crystallization under controlled cooling rates was explored, and the Ozawa theory was employed to describe the non‐isothermal crystallization kinetics. Copyright © 2006 Society of Chemical Industry
Study on spatial–temporal kinetics of photo‐initiated frontal polymerization in stacked reaction cells
Authors: Tao Youji , Yang Jianwen , Zeng Zhaohua , Cui Yanyan , Chen Yonglie 
Published: March 2006

AbstractThe spatial–temporal kinetics for photo‐initiated frontal polymerization(PFP) of isobornyl acrylate with 2,4,6‐trimethylbenzoyldiphenyl phosphine oxide (TPO) as photobleaching initiator was studied experimentally in stacked reaction cells. FTIR and NMR spectroscopy were employed to measure the polymerization conversion, which is dependent on the exposure time, sample depth, light intensity and photo‐initiator concentration. The experimental results are consistent with the theoretical model prediction and show that prolonged irradiation time, higher light intensity and lower photo‐initiator concentration are favorable in enhancing the advance of the polymerization front. The depth‐resolved GPC analysis shows that the average molecular weight of the PFP product dramatically increases with sample depth, while the molecular weight polydispersity reduces steadily with increase in sample depth. Copyright © 2006 Society of Chemical Industry
Synthesis of polyblends from polypropylene and poly(R,S)‐β‐hydroxybutyrate, and their characterization
Authors: Arcana I Made , Sulaeman Aminudin , Pandiangan Kamisah D , Handoko Arie , Ledyastuti Mia 
Published: March 2006

AbstractBlends of modified polypropylene (PP) with poly(R,S)‐β‐hydroxybutyrate (PHB) were prepared by casting polymer solutions, followed by compression molding into thin films. The modified polypropylene was obtained by oxidation with hydrogen peroxide. Oxidation of polypropylene produced new functional groups such as carbonyl and hydroxyl groups on the polymer chain, and a decrease in molecular weight and crystallinity of the polymers. Maximum crystallinity and mechanical properties of the polyblends were found with a PP/PHB ratio of 90/10 (w/w), and then decreased with increasing PHB content in the polyblends. Biodegradability of the polyblends was lower than that of bacterial and synthetic PHBs. Furthermore, an increase of PHB proportion in the polyblends resulted in highly non‐compatible polyblends. Hence only PHB and small parts of the polyblends were decomposed by microorganisms. Copyright © 2006 Society of Chemical Industry
Stabilized dispersions of titania nanoparticles via a sol–gel process and applications in UV‐curable hybrid systems
Authors: Zhang Xiahong , Yang Jianwen , Zeng Zhaohua , Huang Liang , Chen Yonglie , Wang Haihua 
Published: March 2006

AbstractOrganic–inorganic hybrid UV‐curable coatings were synthesized through blending UV‐curable components and stabilized titania sol prepared via a sol–gel process of tetrabutyl titanate (TBT) with three different stabilizers, acetylacetone (Acac), isopropyl tri(dioctyl)pyrophosphato titanate coupling agent (TTPO) and a polymerizable organic phosphoric acid (MAP). The size and the dispersion of titania particle in the UV‐cured organic matrix were dominated by the properties of these stabilizers. A cured hybrid film with titania particle size around 20 nm was obtained when TTPO was utilized as protection agent for the sol. It is interesting that the hardness and flexibility of the photocured hybrid films were improved simultaneously, in contrast to results with neat organic UV‐curable formulations. Copyright © 2006 Society of Chemical Industry
Synthesis and evaluation of photoluminescent and electrochemical properties of new aromatic polyamides and polyimides with a kink 1,2‐phenylenediamine moiety
Authors: Liou Guey‐Sheng , Yang Yi‐Lung , Su Yuhlong Oliver 
Published: March 2006

AbstractA series of novel triphenylamine‐containing aromatic polyamides and polyimides having a crank and twisted noncoplanar structures were synthesized in inherent viscosities of 0.14–0.64 dL/g and 0.11–0.67 dL/g, respectively. These polymers had useful levels of thermal stability associated with relatively high glass‐transition temperatures (174–311 °C). They exhibited strong UV–Vis absorption bands at around 300 nm in NMP solutions. The PL spectra of these polymers in NMP solutions (1 × 10−5 M) showed maximum peaks around 396–479 nm. The hole‐transporting and electrochromic properties were examined by electrochemical and spectroelectrochemical methods. Cyclic voltammetry (CV) of the polymer films cast onto an indium‐tin oxide (ITO)‐coated glass substrate exhibited two reversible oxidation redox couples at potentials of 0.70–1.01 V and 1.10–1.46 V, respectively, vs. Ag/AgCl in acetonitrile solution. The polymer films revealed electrochromic characteristics, with a color change from neutral pale yellowish to green and then to a blue oxidized form at applied potentials ranging from 0.00 to 1.75 V. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 2587–2603, 2006
Acrylic acid level and adhesive performance and peel master‐curves of acrylic pressure‐sensitive adhesives
Authors: Gower M. D. , Shanks R. A. 
Published: March 2006

AbstractThree series of pressure‐sensitive adhesives were prepared with constant glass‐transition temperature, using emulsion polymerization. The monomers chosen were butyl acrylate, 2‐ethylhexyl acrylate (EHA), methyl methacrylate (MMA), and acrylic acid (AA). Within each polymer series, the proportion of AA monomer was held constant for each polymer preparation but acrylic ester monomer levels were varied. Adhesion performance was assessed by measurement of loop tack, static shear resistance, and through the construction of peel master‐curves. Peel master‐curves were generated through peel tests conducted over a range of temperatures and peel rates and through application of the time–temperature superposition principle. Bulk effects dominated by polymer zero shear viscosity change as AA and EHA levels were varied were attributed to the observed effect on static shear resistance and the horizontal displacements of peel master‐curves. Static shear resistance was found to strongly correlate with log(aC), a parameter introduced to horizontally shift peel master‐curves to form a superposed, “super master‐curve”. An interfacial interaction was proposed to account for deviations observed when loop tack was correlated with log(aC). Surface rearrangements via hydrogen bonding with the test substrate were suggested as responsible for the interfacial interaction. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 1237–1252, 2006
Metallocene copolymers of propene and 1‐hexene: The influence of the comonomer content and thermal history on the structure and mechanical properties
Authors: López‐Majada J. M. , Palza H. , Guevara J. L. , Quijada R. , Martínez M. C. , Benavente R. , Pereña J. M. , Pérez E. , Cerrada M. L. 
Published: March 2006

AbstractThe relationships between the structure and properties have been established for copolymers of propylene and 1‐hexene synthesized with an isotactic metallocene catalyst system. The most important factor affecting the structure and properties of these copolymers is the comonomer content. The thermal treatment, that is, the rate of cooling from the melt, is also important. These factors affect the thermal properties, the degree of crystallinity, and therefore the structural parameters and the viscoelastic behavior. A slow cooling from the melt favors the formation of the γ phase instead of the α modification. Regarding the viscoelastic behavior, the β relaxation, associated with the glass‐transition temperature, is shifted to lower temperatures and its intensity is increased as the 1‐hexene content raises. The microhardness values are correlated with those of the storage modulus deduced from dynamic mechanical thermal analysis curves, and good linear relations have been obtained between these parameters. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 1253–1267, 2006
Correlated mutations: Advances and limitations. A study on fusion proteins and on the Cohesin‐Dockerin families
Authors: Halperin Inbal , Wolfson Haim , Nussinov Ruth 
Published: February 2006

AbstractCorrelated mutations have been repeatedly exploited for intramolecular contact map prediction. Over the last decade these efforts yielded several methods for measuring correlated mutations. Nevertheless, the application of correlated mutations for the prediction of intermolecular interactions has not yet been explored. This gap is due to several obstacles, such as 3D complexes availability, paralog discrimination, and the availability of sequence pairs that are required for inter‐ but not intramolecular analyses. Here we selected for analysis fusion protein families that bypass some of these obstacles. We find that several correlated mutation measurements yield reasonable accuracy for intramolecular contact map prediction on the fusion dataset. However, the accuracy level drops sharply in intermolecular contacts prediction. This drop in accuracy does not occur always. In the Cohesin‐Dockerin family, reasonable accuracy is achieved in the prediction of both intra‐ and intermolecular contacts. The Cohesin‐Dockerin family is well suited for correlated mutation analysis. Because, however, this family constitutes a special case (it has radical mutations, has domain repeats, within each species each Dockerin domain interacts with each Cohesin domain, see below), the successful prediction in this family does not point to a general potential in using correlated mutations for predicting intermolecular contacts. Overall, the results of our study indicate that current methodologies of correlated mutations analysis are not suitable for large‐scale intermolecular contact prediction, and thus cannot assist in docking. With current measurements, sequence availability, sequence annotations, and underdeveloped sequence pairing methods, correlated mutations can yield reasonable accuracy only for a handful of families. Proteins 2006. © 2006 Wiley‐Liss, Inc.
Defect‐related emission in CdS films grown directly on hydrogen‐terminated Si(111) substrates
Authors: Seto S. , Kuroda T. , Suzuki K. 
Published: March 2006

AbstractDefect‐related emission at 2.451 eV in epitaxial CdS films on Si(111) substrates was observed for the first time in low‐temperatures photoluminescence spectra. Temperature and excitation intensity dependence of the defect‐related emission were measured to examine its emission mechanism. It was shown that this defect‐related emission in CdS hetero‐epitaxial films exhibits similar behaviours to the so‐called “Y‐line” observed in other zincblende structure II‐VI semiconductor films such as ZnSe/GaAs or ZnTe/GaAs heteroepitaxial films. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Characterization of the vapour grown CdTe crystals for high energy radiation detectors
Authors: Popovych V. D. , Virt I. S. , Tsutsura D. I. , Tsybrii (Ivasiv) Z. F. , Sizov F. F. , Parfenjuk O. A. , Ilashchuk M. I. 
Published: March 2006

AbstractGrowth steps and set‐up for the pure and chlorine doped cadmium telluride single crystals preparation by a vertical configuration of sublimation travelling heater method without seeding are described. The structural, electrical and transport properties of as‐grown material were investigated by different techniques: infrared transmission spectroscopy, double‐crystal X‐ray diffractometry, Hall effect, conductivity, photoelectric measurements and chemical etching. It was concluded that the most suitable material for fabrication of X‐ray and γ‐ray non‐cooling detectors are single crystals doped with Cl in the range of NCl = 1018–1019 cm–3. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Development of high efficient green LEDs of ZnSSe:Te‐ZnMgSSe DH structure on p‐GaAs and its degradation mechanism
Authors: Abe T. , Makimoto K. , Adachi M. , Tanikawa T. , Inoue N. , Nishinaga T. , Kasada H. , Ando K. 
Published: March 2006

AbstractWe present new green double‐hetero (DH) structure light‐emitting diodes (LEDs) of ZnSSe:Te (active layer)–ZnMgSSe (cladding layer) on p‐type GaAs substrates grown by molecular beam epitaxy (MBE).We have confirmed very efficient green emission in Te‐bias modulation doped ZnSSe:Te consists of ZnSSe:Te (Te: 2%, 50 Å)/ZnSSe:Te (Te: 5%, 50 Å) superlattice. A LED with this modulation doping also shows a strong durability for device degradation due to effective Te‐hardening effect. A new LED structure on ptype GaAs exhibits a high extraction efficiency of light emission, which is three times larger in magnitude than LEDs on n‐type GaAs. The new LED also reveals a long device lifetime (in bare chip) over 1300 hours under 3A/cm2 at room temperature. From a simple aging test on the green LEDs, gradual degradation is classified into “slow‐mode degradation”, which is caused by a generation of point defects (donor‐like centers) in p‐type ZnMgSSe cladding layer. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Electrophysical and cathodoluminescent properties of low‐dimensional CdSSe/CdS structure
Authors: Kozlovsky V. I. , Kuznetsov P. I. , Litvinov V. G. , Sannikov D. A. , Yakushcheva G. G. 
Published: March 2006

AbstractThe CdSSe/CdS structure grown by metalorganic vapour phase epitaxy (MOVPE) and prepared for vertical cavity surface emitting laser (VCSEL) was investigated by the capacitance‐voltage characteristics (CV), thermostimulated capacity (TSC), current deep level transient spectroscopy (CDLTS) and cathodoluminescence (CL) methods. Deep levels (DLs) with an activation energies 0.279–1.145 eV were detected by CDLTS and TSC. Hole emission from the ground quantized level in the CdSSe quantum well (QW) was studied. The activation energy of hole emission was used for an estimation of the valence band offset in the type‐II CdSSe/CdS heterostructure. Luminescence and laser properties are discussed. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Complete magneto‐optical TE‐TM mode conversion in Cd1–xMnxTe waveguide for integrated optical isolator
Authors: Debnath M. C. , Zayets V. , Ando K. 
Published: March 2006

AbstractComplete magneto‐optical mode conversion was obtained in a 500 nm‐thick graded‐refractive‐index Cd1–x MnxTe waveguide grown on GaAs substrate. For the annealed waveguide, significant improvement of the complete mode conversion ratio was achieved up to 35 nm operational wavelength range. The Cd1–x MnxTe waveguide also showed very low optical loss of 0.2 dB/cm, high magneto‐optical figure‐of‐merit of more than 1000 deg/dB/kG and isolation ratio of more than 20 dB. This result is an important step toward acheiving a practical integrated optical isolator. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Spin‐polarised carriers in CdS quasi‐spherical quantum dots
Authors: Sprinzl D. , Nahálková P. , Devreese J. T. , Gladilin V. N. , Malý P. , Němec P. 
Published: March 2006

AbstractThe properties of spin‐polarised carriers in quasi‐spherical CdS quantum dots in a strong confinement regime were investigated by photoluminescence and pump‐probe experiments. The obtained results were explained in terms of time‐dependent occupation probabilities for the lowest exciton states. The electron spin flip time of 3.5 ns was measured at room temperature. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Photoluminescence properties of Zn0.77Cd0.23O/Mg0.04Zn0.96O heterostructures
Authors: Nakamura A. , Ishihara J. , Yamamoto K. , Aoki T. , Temmyo J. 
Published: March 2006

AbstractZn1–xCdxO/MgyZn1–yO heterostructures were successfully grown by RPE‐MOCVD and were investigated by photoluminescence (PL) spectroscopy in order to examine the effects on the barrier and active bandgap energy. Double‐heterostructures typically consisting of 15 nm‐thick MgyZn1–yO/z (z = 15, 30, 50, 100 nm)‐thick Zn1–xCdxO/200 nm‐thick MgyZn1–yO were grown on a‐plane sapphire substrate. PL measurements were carried out using a He‐Cd laser (325 nm) at room temperature. The relationship between the dependencies of luminescence intensity and the PL emission wavelength on the Zn1–xCdxO layers by changing the thickness were discussed. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Raman spectra and phonon modes of MgxZn1–xO alloy films
Authors: Wei Z. P. , Lu Y. M. , Shen D. Z. , Zhang Z. Z. , Wu C. X. , Zhang J. Y. , Yao B. , Fan X. W. 
Published: March 2006

AbstractHexagonal MgxZn1–xO alloy layers with 0 ≤ x < 0.3 have been grown by plasma‐assisted molecular beam epitaxy on sapphire (006) and Si (111) substrates. Their crystal structures are characterized by x‐ray diffraction spectroscopy. The nonresonant and resonant Raman spectra were measured using 488 nm line from Ar+ laser, and 325 nm line from He‐Cd laser by backscattering geometry. Four Raman modes (E2high, LO, TO, multiphonon processes) were observed in the nonresonant Raman spectra of hexagonal MgxZn1–xO with different Mg contents. The optical phonon frequencies were found to display one‐mode behaviour for all the samples since no separate ZnO‐ and MgO‐like modes were observed. The long‐wavelength frequencies of ZnO‐like optical phonons measured in the resonant Raman spectra can be expressed as linear functions of x. These behaviours can be explained within a modified random‐element‐ isodisplacement model (MREI). (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Negative U‐properties of the oxygen‐vacancy in ZnO
Authors: Pfisterer Daniel , Sann Joachim , Hofmann Detlev M. , Meyer Bruno , Frank Thomas , Pensl Gerhard , Tena‐Zaera R. , Zúñiga‐Pérez J. , Martinez‐Tomas C. , Muñoz‐Sanjosé V. 
Published: March 2006

AbstractIt is shown that the intensity of the oxygen vacancy (VO) related emission in ZnO at 2.45 eV correlates to the concentration of the donor level E4. E4 is located 530 meV below the conduction band and attributed to the VO0/++ recharging. Deep level transient spectroscopy (DLTS) experiments with optical excitation locate the VO2+/+ level position 140 meV below the conduction band and give evidence for the “negative‐ U” properties of the oxygen vacancies in ZnO. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Spontaneous phase condensation of CdTe exciton‐polaritons
Authors: Kasprzak J. , Richard M. , André R. , Romestain† R. , Malpuech G. , Kavokin A. , Si Dang Le 
Published: March 2006

AbstractWe have studied CdTe/CdMgTe microcavity samples containing 4 quantum wells and characterized by a vacuum field Rabi‐splitting of 13.2 meV. Electron‐hole pairs were excited at 7.3K by linearly‐polarized light at 1.74 eV provided by a Ti:sapphire laser operating in the pulsed mode (at 80 MHz rate). Spectroscopic imaging in reciprocal space as well as near‐field spectroscopy show that, above a critical stimulation threshold, polaritons in our microcavity undergo a spontaneous transition to a condensed phase characterized by the massive occupation of the polariton ground state. The coherence of this quantum state is evidenced by the spectral and angular narrowing of its emission. We point out the conditions which should be fulfilled to achieve BEC of microcavity polaritons. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Characterization of Cd1–x–yBexZnySe mixed crystals via electromodulation spectroscopy
Authors: Liu Y. T. , Sitarek P. , Huang P. J. , Huang Y. S. , Firszt F. , Łęgowski S. , Męczyńska H. , Marasek A. , Paszkowicz W. 
Published: March 2006

AbstractA detailed optical characterization of three wurtzite‐type Cd1–x–yBexZnySe mixed crystals has been carried out by using contactless electroreflectance (CER) and photoreflectance (PR) in the temperature range of 15 to 400 K. The samples were grown by the modified high pressure Bridgman method. The transition energies of the A, B and C features of Cd1–x–yBexZnySe are determined via a lineshape fit to the CER and PR spectra. The parameters that describe the temperature dependence of the interband transition energies of the features A and C are evaluated and discussed. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Effects of substrate temperature upon photoluminescence and electrical properties of ZnTe in atmospheric pressure MOVPE using tris‐dimethylaminophosphorus
Authors: Hayashida Kazuki , Tanaka Tooru , Nishio Mitsuhiro , Guo Qixin , Tanikawa Tuyoshi , Ogawa Hiroshi 
Published: March 2006

AbstractThe effect of substrate temperature upon the photoluminescence (PL) properties of phosphorus‐doped ZnTe layers grown by atmospheric pressure metalorganic vapor phase epitaxy using tris‐dimethylaminophosphorus as a dopant source has been investigated together with the growth rate behaviour. At a substrate temperature of 400 °C corresponding to the growth condition close to the mass transport to surface kinetic transition region, the PL spectrum at 4 K is characterized by a strong Ia and a weak free‐to‐bound transition emission, implying a P‐doped ZnTe layer of good crystalline quality. For the layers grown at the substrate temperatures away from this temperature, on the other hand, a donor‐acceptor pair recombination emission appears in the spectra. The P‐doped layers exhibit only the edge emission at ∼549 nm in the room temperature PL specrum, independent of substrate temperature. The relationship between the electrical properties of P‐doped layers and the substrate temperature has also clarified. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)