bluuebunny/crossref_metadata_2025_split huggingface dataset:
Selective self‐ion/molecule reactions in both external and internal source ion trap mass spectrometers
Authors: Wu Hui‐Fen , Ho Ming‐Yi 
Published: September 2002

AbstractNovel results on the selective self‐ion/molecule reactions (SSIMR) in both external and internal source ion trap mass spectrometers are demonstrated. Selective self‐ion/molecule reaction product ions were produced between the oxygenated and nitrogenated crown ethers. For the oxygenated crown ethers, self‐ion/molecule reactions lead to the formation of the protonated ions, adduct ions of fragments ([M + F]+) and [M + H3O]+, while the nitrogenated crown ethers produce [M + H]+, [M + CH]+ and [M + C2H3]+ ions. Copyright © 2001 John Wiley & Sons, Ltd.
New aspects in matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry: a universal solvent‐free sample preparation
Authors: Trimpin S. , Rouhanipour A. , Az R. , Räder H. J. , Müllen K. 
Published: September 2002

AbstractA method of solvent‐free sample preparation is shown to be of universal applicability for matrix‐assisted laser desorption/ionization mass spectrometry (MALDI‐MS). Results obtained were compared with those of traditional solvent‐based sample preparation for MALDI‐MS in order to demonstrate their similarities with respect to accuracy, sensitivity and resolution for polymers such as polystyrene and poly(methyl methacrylate) in a mass range from 2 to 100 kDa. The results revealed that there is fundamentally no difference in the quality of the obtained mass spectra, and we conclude that the mechanism of desorption and ionization remains unchanged. However, the solvent‐free sample preparation turned out to have some advantages over the traditional method in certain cases: quick and easy applicability is shown for polyetherimide avoiding time‐consuming optimization procedures. In particular, industrial pigments that are insoluble in common solvents were characterized without interfering signals from fragments. The method even showed improvements with respect to reproducibility and mass discrimination effects in comparison to traditional sample preparation. Additionally, this contribution provides new insight regarding the analyte/matrix preorganization for the desorption step which now appears to be independent of crystallinity. Copyright © 2001 John Wiley & Sons, Ltd.
Rapid breakthrough into the unconscious of a depressed and masochistic patient in an initial two‐hour therapy session
Authors: Slote Gilbert M. 
Published: September 2002

AbstractIn this article the author presents a rapid breakthrough into the unconscious of a patient by applying Dr Habib Davanloo's Central Dynamic Sequence focusing particularly on the phases of pressure and challenge leading to a crystallization of the patient's defenses in the transference. Technical interventions to exert pressure and challenge in the transference are presented as well as the types of defenses these interventions are intended to counteract. Each intervention by the therapist, and the corresponding response of the patient is analyzed. Copyright © 2000 John Wiley & Sons, Ltd.
Dynamic SIMS characterization of interface structure of Ag/Alq3/NPB/ITO model devices
Authors: Song Weijie , Li Zhanping , So S. K. , Qiu Yong , Zhu Youngfa , Cao Lili 
Published: September 2002

AbstractIn this study, we first profiled model organic light‐emitting diodes (OLEDs) with the structure Ag/tris(8‐hydroxyquinoline) aluminium (Alq3)/N,N′‐diphenyl‐N,N′‐bis[1‐naphthyl‐(1,1′‐biphenyl]‐4,4′‐diamine (NPB)/indium tin oxide (ITO) using dynamic SIMS. The element distribution across the multilayer and the dynamic SIMS spectra at different regions were obtained. It was shown that dynamic SIMS is a powerful tool in profiling OLEDs. Clear diffusion of Ag into the Alq3 layer was observed. The experimental results also revealed that a distinct interface for Alq3/NPB can be obtained using dynamic SIMS. Copyright © 2001 John Wiley & Sons, Ltd.
XPS characterization of zeolite catalyst in plasma catalytic methane conversion
Authors: He Fei , Liu Chang‐jun , Eliasson Baldur , Xue Bingzhang 
Published: September 2002

AbstractDirect plasma methane conversion to higher hydrocarbons using pure methane feed is almost impossible without using zeolite. In the presence of zeolite, such direct conversion leads to a very high yield of higher hydrocarbons. The use of zeolite not only inhibits the formation of non‐selective carbon black and plasma‐polymerized films but also significantly increases the selectivity of light hydrocarbons during plasma methane conversion with dielectric barrier discharge (DBD). The DBD plasma‐used zeolite has been characterized by x‐ray photoelectron spectroscopy (XPS) and suggests the DBD plasmas have led to reactions within the channel of zeolite. The present investigation gives us more supporting results for the proposed mechanism of plasma‐promoted catalysis. Copyright © 2001 John Wiley & Sons, Ltd.
Temperature‐programmed surface reaction study on C2‐oxygenate synthesis over SiO2 and nanoporous zeolitic material supported Rh–Mn catalysts
Authors: Ma Hongtao , Yuan Zhongyong , Wang Yi , Bao Xinhe 
Published: September 2002

AbstractTemperature‐programmed surface reaction (TPSR), temperature‐programmed reaction (TPR) and temperature‐programmed desorption (TPD) were used to study the synthesis of C2‐oxygenates from syngas over Rh–Mn‐based catalysts supported on amorphous silica and mesoporous MCM‐41 supports. Both TPD and TPSR reveal the existence of several different kinds of CO species on the catalyst surface in the course of the catalytic reaction (linear, geminal, bridged and tilt‐adsorbed CO species) but only the bridged form and tilt‐adsorbed CO species are the precursors for CO dissociation and the formation of C2‐oxygenates. The formation temperature of acetaldehyde is higher than that of ethanol, which suggests that they may be formed via different mechanisms. The ethanol formation activity over the Rh–Mn/MCM‐41 catalyst is lower than that over the Rh–Mn/SiO2, which suggests that the number of active sites for ethanol formation are fewer on the surface of Rh–Mn/MCM‐41. However, the acetaldehyde formation activities are almost identical for the Rh–Mn catalysts supported on amorphous SiO2 and MCM‐41, meaning that acetaldehyde and ethanol might be formed on different active sites. Copyright © 2001 John Wiley & Sons, Ltd.
Theoretical study of the effects of intermolecular interactions in self‐assembled long‐chain alkanes adsorbed on graphite surface
Authors: Yin Shuxia , Wang Chen , Qiu Xiaohui , Xu Bo , Bai Chunli 
Published: September 2002

AbstractIn this paper, we studied the physisorption of long‐chain alkanes CnH2n+2 (n = 8, 16, 24, 34) on a graphite surface using molecular mechanics simulations. The computed results illustrated that the interactions between adsorbed molecules and substrate are dominated by van der Waals forces whereas the electrostatic interactions are very small. It was found that the ratio of the alkane molecule–molecule interactions (two‐dimensional crystallization energy) to the interactions between alkane and graphite (adsorption energy) ranges from ∼2 : 5 to 3 : 5. The adsorption stability and immobility of the alkanes increases proportionally with an increase in the chain length. It was concluded that the lateral interactions between adsorbed molecules are important to the formation of ordered two‐dimensional lamellae. The theoretical results support the scanning tunneling microscopy (STM) observation of alkylated aromatic compounds on a graphite surface. Copyright © 2001 John Wiley & Sons, Ltd.
Application of focused ion beam lift‐out specimen preparation to TEM, SEM, STEM, AES and SIMS analysis
Authors: Stevie F. A. , Vartuli C. B. , Giannuzzi L. A. , Shofner T. L. , Brown S. R. , Rossie B. , Hillion F. , Mills R. H. , Antonell M. , Irwin R. B. , Purcell B. M. 
Published: September 2002

AbstractCommercially available focused ion beam (FIB) workstations with spatial resolution of 5–7 nm can prepare specimens with excellent lateral resolution. This capability has been utilized extensively by the semiconductor industry to obtain materials characterization from continually smaller areas. The FIB has been adopted generally as a preparation tool for scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The ability to prepare site‐specific specimens that can be removed from the bulk of a sample provides enhanced SEM and TEM analyses and new approaches for other analytical tools. Dedicated scanning transmission electron microscopy (STEM) can provide images through samples several micrometers thick. Auger electron spectroscopy (AES) can analyze with improved ability to identify a small particle. Secondary ion mass spectrometry (SIMS) can provide trace analysis at high mass resolution. Automatic operation of FIB workstations permits the creation of multiple lift‐out samples without the presence of an operator. Copyright © 2001 John Wiley & Sons, Ltd.
ToF‐SIMS study of the surface morphology of blends of polystyrene and poly(N‐vinyl‐2‐pyrrolidone) compatibilized by poly(styrene‐co‐4‐vinylphenol)
Authors: Zeng X. M. , Weng L. T. , Li L. , Chan C.‐M. , Liu S. Y. , Jiang M. 
Published: September 2002

AbstractThe influence of the vinylphenol content of poly(styrene‐co‐4‐vinylphenol) (STVPh) on the surface morphology of a blend of polystyrene (PS) and poly(N‐vinyl‐2‐pyrrolidone) (PVP) was investigated by time‐of‐flight secondary ion mass spectrometry (ToF‐SIMS) chemical imaging. The images obtained through the use of the ToF‐SIMS positive total ions and selected negative ions clearly show that the characteristic size of the dispersed phase (PVP) decreased with the addition of the STVPh‐5 (5 mol.% vinylphenol) random copolymer. The spectra obtained retrospectively from the matrix and the dispersed phase indicated that the matrix phase was very similar to the pure PS and that the dispersed phase was very similar to the pure PVP. The addition of the STVPh‐9 random copolymer to the blend of PS and PVP resulted in a totally different morphology: both PVP and PS became semi‐continuous and the dispersed particles are much larger. The morphological changes were caused by the formation of a single phase between PVP and STVPh‐9 due to an increase in the density of the hydrogen bond formed between PVP and STVPh‐9. When the vinylphenol content was <2 mol.%, the particle size of the PVP‐rich phase stayed the same. The compatibilizing effect was much weakened as the concentration of STVPh‐5 decreased to 1 wt.%. Copyright © 2001 John Wiley & Sons, Ltd.
Analysis of potentiostatic current transients at metal/liquid interfaces: resolving the effects of a finite step interval
Authors: Garland J. E. , Pettit C. M. , Walters M. J. , Roy D. 
Published: September 2002

AbstractPotentiostatic current transients are used routinely for electrochemical analysis of metal/liquid interfaces. These measurements can be affected by both the electrochemical cell and the potentiostat used for such experiments. We demonstrate this in the present report with double‐layer charging experiments using a gold electrode in aqueous electrolytes of NaF and NaNO3. By employing a high‐resolution potentiostat, we show that the apparently instantaneous voltage step actually has a finite temporal width. The double‐layer charging current develops an additional feature due to this behavior of the voltage step. We present a theoretical framework to resolve these instrumental effects from the actual electrical response of the double layer. The results are compared with a set of independent measurements of the same quantities using impedance spectroscopy. Copyright © 2001 John Wiley & Sons, Ltd.
Innovative sample preparation for GDOES analysis of decarburized layers in cylindrical metal specimens
Authors: Bellini S. , Cilia M. , Piccolo E. Lo 
Published: September 2002

AbstractGlow discharge optical emission spectrometry (GDOES) is a technique widely used for depth profile analysis but there are two significant limitations: samples must have planar surfaces and profile analysis generally cannot go beyond a depth of 100 µm. A new method of sample preparation has been developed to overcome both of these limitations, consisting of plastic deformation of the curved sample by pressing it until a planar surface is obtained. Furthermore, after profile analysis, the surface surrounding the glow‐discharged zone of the sample is ground to obtain a uniform layer levelled down to the bottom of the crater. Repeated grinding operations and profile analyses allow analysis of samples with practically unlimited thickness. An application of this method to determine the entity of the decarburized layer on a carbon steel rod sample is described in this paper. Copyright © 2001 John Wiley & Sons, Ltd.
Apatite films produced by electrodeposition: characterization by TEM and AFM
Authors: Manso Miguel , Jiménez Carmen , Morant Carmen , Herrero Pilar , Martínez‐Duart J. M. 
Published: September 2002

AbstractApatite films have been grown by a method involving both physical and chemical processes. The spontaneous nucleation of apatite crystals on the surface of Ti/Si and Si substrates was activated by applying positive constant potentials. The surface morphology and microstructure of these films have been studied. Several apatite‐like nanocrystals have been observed in the bulk by high‐resolution transmission electron microscopy. We also observed ordered structures with atomic resolution on the surface using atomic force microscopy. The results of the combined characterization suggest that this is a useful technique for low‐temperature deposition of thin apatite films on both semiconductor and metallic substrates. Copyright © 2001 John Wiley & Sons, Ltd.
Surface modification of a silicate glass during XPS experiments
Authors: Sharma A. , Jain H. , Miller A. C. 
Published: September 2002

AbstractThe surface chemistry of a commercial soda‐lime silicate glass is shown to change during a long‐duration XPS experiment wherein the glass surface was exposed to the monochromatic x‐rays and low‐energy electrons (0.2–5 eV) that compensate for the charging of the surface. The atomic percentage of sodium increases and that of oxygen decreases with increasing time of the experiment. The separate influence of x‐rays and the low‐energy electrons on the glass surface is also measured. The results show that diffusion of the sodium ions is enhanced more in the presence of x‐rays than in the presence of low‐energy electrons. All observations can be explained well by a model that considers the breaking of the bridging and non‐bridging oxygen bonds, and the trapping of photoelectrons and the externally supplied electrons. Although long‐duration XPS experiments show significant changes on the exposed surface, the chemical composition of the bulk glass obtained during a short experiment agrees well with that obtained from the chemical analysis. Copyright © 2001 John Wiley & Sons, Ltd.
Use of Auger parameter and Wagner plot in the characterization of Cu‐ZSM‐5 catalysts
Authors: Moretti Giuliano , Filippone Francesco , Satta Mauro 
Published: September 2002

AbstractThe use of the Auger parameter, the Wagner plot and a simple electrostatic model permits the determination of the local electronic and geometrical structure of Cu+ sites in Cu‐ZSM‐5 catalysts. The results are in agreement with previous extended X‐ray absorption fine structure (EXAFS) and X‐ray absorption near‐edge structure (XANES) studies. Copyright © 2001 John Wiley & Sons, Ltd.
Use of XPS for the study of cerium–vanadium (electrochromic) mixed oxides
Authors: Salvi A. M. , Decker F. , Varsano F. , Speranza G. 
Published: September 2002

AbstractResearch studies on new materials have shown that cerium–vanadium mixed oxides have potential for use as counter‐electrodes in electrochromic devices owing to the combination of the excellent stability and transparency of cerium oxides and the high ion‐storage capacity of the vanadium oxides.Among them, cerium orthovanadate (CeVO4) has shown its potentiality as an intercalation electrode of suitable structure into which ions can be inserted reversibly, thus balancing the ion‐charge capacity required by WO3, which is the colouring electrode in electrochromic devices.In this work, cerium–vanadium stoichiometric oxides (CeO2–V2O5, 1 : 1 molar ratio) have been used as a target material for r.f.‐sputtering thin‐film deposition onto suitable substrates. The films obtained have been characterized before and after electrochemical lithium intercalation. Their XPS and x‐ray‐induced Auger electron spectroscopy spectra have been compared with those obtained with the standard precursor oxides and the results discussed also on the basis of literature data.In order to be able to observe the changes in chemical state and composition expected on film formation, a careful curve‐fitting procedure has been used that allows the determination of the background structure and intrinsic satellites for each peak, as reported already in previous papers. Copyright © 2001 John Wiley & Sons, Ltd.
Line structure in photoelectron and Auger electron spectra of CuOx/Cu and Cu by Auger photoelectron coincidence spectroscopy (APECS)
Authors: Jiang Zhong‐Tao , Thurgate Stephen M. , Wilkie Peter 
Published: September 2002

AbstractIn this study, we present Cu L3M45M45 Auger spectra in coincidence with Cu 2p3/2 from the oxidized surface of Cu (i.e. CuOx/Cu) and Cu 2p3/2 lines in coincidence with Auger 1G and 3F terms of Cu L3VV from Cu. Comparison of the L3VV line structures of CuOx/Cu with that of Cu reveals that the Auger line has changed to band‐like in the CuOx/Cu material. The reduced mean free path of the Auger electron in coincidence with the photoelectron displays the Auger line of the CuOx surface. The asymmetric broadening of the Cu 2p3/2 lines in coincidence with 1G and 3F terms from Cu illustrates that a single‐step model is essential for describing the Auger lineshape of copper. Copyright © 2001 John Wiley & Sons, Ltd.
Molecular dynamics simulation of the cluster‐ impact‐induced molecular desorption process
Authors: Webb Roger , Kerford Michelle , Ali Elliot , Dunn Michelle , Knowles Luke , Lee Kenneth , Mistry Jitesh , Whitefoot Francis 
Published: September 2002

AbstractMolecular dynamics computer simulation is used to investigate the effects of cluster surface interactions and their use to desorb molecules from a surface. Of interest here is the interaction of fullerenes with a graphite surface and in particular cluster impact desorption of adsorbed molecules from the graphite surface.It has been shown recently how impacts from fullerenes on graphite cause an acoustic wave to propagate across the surface from the impact site. In the work presented here it is shown that this wave can be used to desorb intact molecules that are weakly bonded by Van der Waals forces to the surface. The ultimate objective is to desorb molecules the size of genes. Using C60, a wave can be created that is strong enough to desorb 15 benzene molecules without breaking either the surface of the graphite or any of the benzene molecules. It is unlikely that this will be strong enough to desorb a high‐mass gene. By increasing the initial energy of the C60, we desorb a larger number of molecules but at the expense of breaking the surface, losing the coherence of the acoustic wave and breaking many of the benzene molecules. However, if the size of the impacting molecule is increased to that of a 300‐particle ‘onion’‐type structure, it is possible to increase greatly the power of the acoustic wave, thereby desorbing many more benzene molecules from the surface without causing any damage to the surface, the fullerene or to the benzene molecules themselves. Copyright © 2001 John Wiley & Sons, Ltd.
Bioengineered material surfaces for medical applications
Authors: Mathieu Hans Jörg 
Published: September 2002

AbstractMan‐made materials are increasingly being applied as substitutes for defective functions in human hosts. These biomaterials may be non‐viable materials used in medical devices interacting with biological systems. Such engineered materials should be biocompatible, i.e. with minimal non‐specific protein adsorption. This paper describes the functionalization of soft biomaterial surfaces and diamond‐covered silicon wafers controlled by surface spectroscopies such as x‐ray photoelectron spectroscopy (XPS) and time‐of‐flight secondary ion mass spectrometry (ToF‐SIMS), as well as contact angle measurements and scanning force microscopy (SFM). Surface functionalization is obtained with molecules such as phosphorylcholine, carbohydrates, dextran or peptides added to various soft and hard materials. Surface analytical tools are able to control the chemistry, energy and topography of surfaces and thin films with high sensitivity down to the femtomole range and nanometer resolution. Copyright © 2001 John Wiley & Sons, Ltd.
Chromosomal fragile sites and relationship between genetic predisposition to small cell lung cancer
Authors: Karadağ M. , Tunca B. , Çeçener G. , Egeli Ü. , Özyardimci N. , Ege E. , Gözü O. 
Published: September 2002

AbstractFragile sites are non‐staining gaps and breaks on mammalian chromosomes. Several investigators have pointed out that these sites may act as factors that predispose to specific chromosomal rearrangements that are present in some cancer cases. The expression of common fragile sites induced by aphidicolin (Apc) was evaluated on prometaphase chromosomes obtained from the peripheral blood lymphocytes of 15 patients with lung cancer, 20 of their clinically healthy family members, and 20 age‐matched normal controls. As a result of cytogenetic evaluation carried out by the High Resolution Banding (HRB) technique, 1q21, 2q33, 3p14, 7q32, 13q13, 16q23, 17q21, and 22q12 are defined as fragile sites in patients and relatives. The rate of total fragile sites and 2q33, 3p14, and 16q23 are statistically significant in both patients and relatives when compared with the control group. Therefore, our results showed that common fragile sites might be unstable factors in the human genome and they can be used as suitable markers for genetic predisposition to lung cancer. Teratogenesis Carcinog. Mutagen. 22:31–40, 2002. © 2002 Wiley‐Liss, Inc.
Inhibition of telomerase activity in endometrial cancer cells by selenium‐cisplatin conjugate despite suppression of its DNA‐damaging activity by sodium ascorbate
Authors: Błasiak Janusz , Kadłubek Magdalena , Kowalik Joanna , Romanowicz‐Makowska Hanna , Pertyński Tomasz 
Published: September 2002

AbstractTelomerase activation can be considered as a critical step in cell immortalization. The enzyme elongates or maintains telomere length by adding to its end tandem TTAGGG repeats by using its endogenous RNA template. Telomerase is not detectable in most somatic cells but is upregulated in germ line cells and in 85–90% of human cancers, which suggests important role of telomerase in neoplastic transformation. Consequently, telomerase has been proposed as a potentially highly selective target for the development of antiproliferative agents. Platinum complexes are widely administrated in cancer therapy. A conjugate of selenite with diammineplatinum [(NH3)2Pt(SeO3)2] is a novel potential anticancer drug. Using alkaline single cell gel electrophoresis (comet assay), we showed that the drug at 5–30 μM induced concentration‐dependent damage to DNA of endometrial cancer cells derived from tumor samples. Sodium ascorbate at 10 and 50 μM reduced the extent of the DNA damage evoked by the drug. (NH3)2Pt(SeO3) reduced telomerase activity in the cells in a concentration‐dependent manner as measured by using the telomere repeat amplification protocol (TRAP) assay. This effect was independent of sodium ascorbate. Therefore, mutagenic effects of the conjugate can be reduced by well‐recognized antimutagen, sodium ascorbate, but it can still retain ability to affect neoplastic transformation. The results obtained indicate that (NH3)2Pt(SeO3) may specifically inhibit telomerase activity in endometrial cancer cells. Teratogenesis Carcinog. Mutagen. 22:73–82, 2002. © 2002 Wiley‐Liss, Inc.