Rainer Jaenicke1993-03-29Philosophical Transactions of the Royal Society B Biological Sciences
The classical in vitro denaturation-renaturation studies by Anson, Anfinsen, Neurath, Pauling and others clearly suggested that the primary structure of proteins determines all higher levels of protein structure. Protein folding in the cell is inaccessible to a detailed analysis of its kinetic mechanism. There are obv…
Protein Structure and DynamicsEndoplasmic Reticulum Stress and DiseaseEnzyme Structure and Function
K. Hricovíni、Ramses Günther、P. Thiry 等 13 位作者1993-03-29Physical Review Letters
The valence and core level spectra of chemically prepared, ideally H-terminated Si(111) surfaces are characterized by remarkably sharp features. The valence band levels and their dispersion are well described by first-principles calculations using a quasiparticle self-energy approach within the GW approximation. From…
Advanced Chemical Physics StudiesSemiconductor materials and devicesElectron and X-Ray Spectroscopy Techniques
Tae Ho Yeom、Sung Ho Choh、Mao Lu Du1993-03-29Journal of Physics Condensed Matter
The zero-field splitting (ZFS) parameters D, E and F for an Mn 2+ centre in a BiVO 4 single crystal are calculated using the point-charge electrostatic model and the superposition model. The calculated ZFS parameters at the Bi and V sites are compared with the experimental values for Mn 2+ . The calculated second-orde…
Luminescence Properties of Advanced MaterialsPerovskite Materials and ApplicationsSolid-state spectroscopy and crystallography
Xin Gu1993-03-29Applied Physics Letters
Raman spectra of polyimide films were studied before and after being irradiated with 308 nm excimer laser pulses in order to understand the conductivity increase induced by ultraviolet irradiation. Changes in the chemical structure of polyimide were observed. A possible mechanism responsible for the ultraviolet induce…
Diamond and Carbon-based Materials ResearchAnalytical Chemistry and SensorsPolymer Nanocomposite Synthesis and Irradiation
V.S. Veerasamy、G.A.J. Amaratunga、C. A. Davis 等 6 位作者1993-03-29Journal of Physics Condensed Matter
The ability to control the electrical resistivity of semiconducting tetrahedral amorphous carbon (ta-C) films is reported. Phosphorus is incorporated during film growth from a plasma formed with a cathodic vacuum arc by using a phosphorus-containing carbon cathode. By changing the P content in the cathode from 0-1% ma…
Metal and Thin Film MechanicsSemiconductor materials and devicesDiamond and Carbon-based Materials Research
Veli‐Matti Mukkala、Marek Kwiatkowski、Jouko Kankare 等 4 位作者1993-03-24Helvetica Chimica Acta
Abstract Eight different 2,2′‐bipyridine derivatives, i.e . 2, 5, 8, 10, 12, 13, 15 , and 19 ( Schemes 1 and 2 ), were prepared to study the influence of the chelating groups on the luminescence properties of their Eu III and Tb III chelates. According to our luminescence results, 2,2′‐(methylenenitrilo)bis(acetic aci…
Advanced MRI Techniques and ApplicationsMedical Imaging Techniques and ApplicationsLanthanide and Transition Metal Complexes
Lucas Auer、Christophe Weymuth、Rolf Scheffold1993-03-24Helvetica Chimica Acta
Abstract A Mixture of (3 S ,6 R )‐ and (3 R ,6 R )‐3‐methyl‐6‐(1‐methylethenyl)dec‐9‐enyl acetate ( 1a and 1b , respectively)– 1a being a pheromone of the California red scale – is synthesized in 14 steps from (+)‐( R )‐limonene ( 4 ). The key step is the reductive vitamin‐ B 12 ‐catalyzed coupling of ( R )‐5‐(2‐iodoe…
Enzyme Catalysis and ImmobilizationPorphyrin and Phthalocyanine ChemistryPorphyrin Metabolism and Disorders
George S. Attard、Corrie T. Imrie、Frank E. Karasz1993-03-23ChemInform
Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” opt…
Liquid Crystal Research AdvancementsSynthesis and properties of polymersCoordination Chemistry and Organometallics
P.C. de Smidt、Astrid Versluis、Theo J.C. van Berkel1993-03-23Biochemistry
In the photodynamic therapy of cancer, research has focused on the influence of lipoproteins (particularly the low-density lipoprotein, LDL) on the fate and transport of the porphyrin mixture. We have studied the interaction between LDL and a series of well-defined tetraphenylporphinesulfonates, TPPS-1, TPPS-2A, and T…
Porphyrin and Phthalocyanine ChemistryPhotodynamic Therapy Research StudiesMetal-Catalyzed Oxygenation Mechanisms
T.K. Gundu Rao、B. C. Bhatt、J. K. Srivastava 等 4 位作者1993-03-22Journal of Physics Condensed Matter
The defect centres formed in the thermoluminescent phosphor CaSO 4 :Dy on additionally doping with Na + (as a charge compensator) have been studied using the technique of electron paramagnetic resonance. The Na + ion at the Ca 2+ site is found to stabilize the observed SO 4 - radical. An important feature of the new S…
Advanced Chemical Physics StudiesLuminescence Properties of Advanced MaterialsSolid-state spectroscopy and crystallography
Paul Drzaic、Anne M. Gonzales1993-03-22Applied Physics Letters
We compare the light scattering properties of polymer-dispersed liquid crystal films incorporating different nematic mixtures. We find that, when powered, the turbidity of these disparate films share a common quadratic dependence on the refractive index difference between the nematic and polymer. In contrast, when we…
Liquid Crystal Research AdvancementsPhotonic Crystals and ApplicationsSurfactants and Colloidal Systems
Philip E. Batson1993-03-22Physical Review Letters
Inelastic electron scattering using a two-beam channeling condition is used for the first time to create excitations having selectable even or odd symmetry relative to an atom column. The method is first established using plasmon and interband scattering in diamond. Next, for the carbon 1s absorption edge, scattering…
Semiconductor materials and devicesDiamond and Carbon-based Materials ResearchElectronic and Structural Properties of Oxides
P. B. Fischer、Stephen Y. Chou1993-03-22Applied Physics Letters
We present the fabrication of sub-50 nm Si pillars, ridges, and trenches with aspect ratios greater than 10 using ultrahigh resolution electron beam lithography and chlorine based reactive ion etching. These nanoscale Si features can be further reduced to 10 nm using an additional HF wet etch. No photoluminescence was…
Semiconductor materials and devicesSilicon Nanostructures and PhotoluminescenceNanowire Synthesis and Applications
J. A. Borchers、M. J. Carey、R. W. Erwin 等 5 位作者1993-03-22Physical Review Letters
Neutron diffraction measurements confirm the presence of long-range antiferromagnetic order in superlattices of cobalt oxide and nickel oxide. A single transition temperature between the values for bulk CoO and NiO is evident for two samples with 36 \AA{} periods as previously reported, but the separate Ni and Co orde…
Magnetic properties of thin filmsZnO doping and propertiesMagnetic and transport properties of perovskites and related materials
Ch. Bahr、D. Fliegner1993-03-22Physical Review Letters
Free-standing films of a smectic liquid crystal possessing the bulk phase sequence smectic A, ferroelectric smectic C, antiferroelectric smectic ${\mathit{C}}_{\mathit{A}}$ are studied. Using ellipsometric measurements, we show that the bulk phases still exist in films consisting of only four, three, and even two smec…
Liquid Crystal Research AdvancementsSurfactants and Colloidal SystemsNonlinear Dynamics and Pattern Formation
Nobuaki Noguchi、I. Suemune1993-03-22Applied Physics Letters
Photosynthesis of porous silicon is reported for the first time with visible-light irradiation in a hydrofluoric acid solution, which does not need any electrodes for anodization. The photosynthesized porous layer consisted of microparticles, and the photoluminescence spectra were very close to those of anodized porou…
Semiconductor materials and devicesSilicon Nanostructures and PhotoluminescenceNanowire Synthesis and Applications
G. P. Crawford、Renate Ondris-Crawford、S. Žumer 等 4 位作者1993-03-22Physical Review Letters
Deuterium magnetic resonance of cylindrically confined liquid crystals reveal a structural transition driven by a homeotropic-to-planar anchoring transition in the nematic phase and an orientational wetting (quasicomplete-to-partial) transition in the isotropic phase as the molecular length of the surface coupling age…
Liquid Crystal Research AdvancementsMaterial Dynamics and PropertiesMolecular spectroscopy and chirality
Jean‐Christophe Charlier、J.-P. Michenaud1993-03-22Physical Review Letters
We study the structure of nested multilayered systems composed of two infinite carbon tubules via density functional theory. The calculated intertubule distance is 3.39 \AA{}, comparable to the recent measurement of 3.4 \AA{}. In such a system, the energy gained by adding a new cylindrical layer around a central one i…
Carbon Nanotubes in CompositesGraphene research and applicationsFullerene Chemistry and Applications
J. Ruan、W. J. Choyke、Koji Kobashi1993-03-22Applied Physics Letters
Diamond films are grown using microwave-plasma-enhanced chemical vapor deposition (CVD). Some samples are deposited using 0.1% oxygen in the reaction gas mixture. We have measured the cathodoluminescence spectra of these diamond films (at 77 K) and found that there is a significant difference between the samples grown…
Metal and Thin Film MechanicsDiamond and Carbon-based Materials ResearchIon-surface interactions and analysis
Tomoyuki Kasemura、Yoshihiro Oshibe、H. Uozumi 等 7 位作者1993-03-20Journal of Applied Polymer Science
Abstract To improve oil and water repellency, fluorine‐containing block copolymers, which were composed of methyl methacrylate (MMA), glycidyl methacrylate (GMA), and 1H, 1H, 2H, 2H‐heptadecafluorodecyl acrylate (PFA), were blended with an epoxy resin. It was expected that a glycidyl group would mesh with the epoxy re…
Surface Modification and SuperhydrophobicityHigh voltage insulation and dielectric phenomenaOffshore Engineering and Technologies