bluuebunny/crossref_metadata_2025 huggingface dataset:
Analysis of Overlapping Bands by an Analytic Geometric Approach: The Potential of Band-Stripping and the Complementary Matching Method in Extraction of Band Components from Overlapping Bands
Authors: Koashi Katsue , Ozaki Yukihiro
Published: April 2004

As a novel method for extracting individual band components from heavily overlapping bands, we propose a band stripping/complementary matching method that is based on first-derivative–second-derivative (D1–D2) plots of an experimental spectrum, coupled with a new concept called a complementary band. By using the concept of complement of a set, the ith band can be indirectly expressed by using a complementary band created by subtracting all the bands, exclusive of the ith estimated band, from an experimental spectrum. The degree of coincidence of both shapes between an estimated band and its complementary band provides a very suitable measure for the quality of fit for each individual band. The analysis method consists of two stages. The first stage is concerned with the geometric approach, which estimates a set of values for the parameters of a component band in the overlapping bands, and repeats band decomposition of the remaining bands in the same manner after removing the estimated band from the overlapping bands. The second stage is to minimize the difference between the profiles of the estimated band and its complementary band by a least-squares optimization and then determine the optimum values of the band parameters with the best-fit band shape. The algorithm and procedures of this method are illustrated by use of a synthetic spectrum consisting of a number of component bands, a background component, and random noise. The quality of fit is so satisfactory in terms of the coincidence between the individual estimated band and the corresponding complementary one that visual observation permits us to determine the optimum estimates of the band parameters and avoid potential problems of curve fitting.
Quantitative Analysis of Vitamin A Degradation by Raman Spectroscopy
Authors: Failloux Nelly , Bonnet Isabelle , Baron Marie-Hélène , Perrier Eric
Published: April 2004

Vitamin A is known to support cell growth promotion, maintenance, and differentiation of epithelial tissues. Retinol is currently used in cosmetic formulations and products to deliver these and other benefits to the skin. However, retinol is known to be unstable and, therefore, remains of great concern to the cosmetic industry. The decomposition pathways of the retinoids in general have been previously postulated and investigated mostly by high-performance liquid chromatography (HPLC) with UV/Vis spectroscopy. In our studies, we examined specific conditions at which retinol degrades and subsequently identified and quantified the products of retinol decomposition by Raman spectroscopy. We reveal which experimental settings and computational tools allow monitoring of in situ evolution of an all-trans retinol solution when submitted to UV light in the presence of oxygen.
Multi-Analyte Calibration Curve for High-Performance Liquid Chromatography with an Inductively Coupled Plasma Carbon Emission Detector
Authors: Peters Heather L. , Hou Xiandeng , Jones Bradley T.
Published: April 2004

A liquid chromatography system with an inductively coupled plasma detector is used to prepare a single calibration curve that is useful for multiple analytes. The detector monitors the atomic emission from carbon at 193.09 nm. Hence, the analytes need not exhibit appreciable molar absorptivity or native fluorescence. Since the carbon signal is independent of molecular structure, the sensitivities for different compounds are similar as long as nebulization efficiencies are comparable. In fact, with a suitable internal standard, no calibration curve is necessary. The capability of the system is demonstrated with a test mixture of nine amino acids separated with a C30 reversed-phase column and a 20 mM phosphate buffered mobile phase. The system provides a detection limit of 30 ng carbon. A multi-analyte calibration curve is prepared with 135 distinct measurements: each of nine analytes, at five different concentrations, repeated in triplicate. The average relative standard deviation for 27 measurements of different amino acids at a given concentration is 2.5%. Clearly, a single analyte will suffice for the calibration of all nine test compounds. Similarly, the internal standard method provides an average percent error of 2.0% for the determination of 45 different amino acid concentrations using only a single replicate for each sample.
Quantitative Estimation of Property Parameters of Crude Oil Using Two-Dimensional 13C–1H J-resolved Nuclear Magnetic Resonance Spectroscopy (HET-JRES)
Authors: Peng Shilin , Ye Chaohui , Liu Maili
Published: April 2004

The physical and chemical properties of crude oil depend on the type and relative amount of hydrocarbons present. When it is not possible to elucidate the exact composition of the oil, “average structural information” may be a meaningful description of the bulk properties of the oil. In this paper, the application of NMR for this purpose has been extended by the use of two-dimensional (2D) 13C–1H J-resolved spectroscopy (HET-JRES) to obtain the average structural information of a set of crude oils. This makes it possible to estimate the molar concentration of the different CH n ( n = 0, 1, 2, 3) spin systems in the sample. It is demonstrated here that structural information, derived from HET-JRES, correlates with the density and viscosity of the crude oils. Hence this new approach, which is rapid, may represent a useful method for crude oil characterization.
Novel Method for Preparing Controllable and Stable Silver Particle Films for Surface-Enhanced Raman Scattering Spectroscopy
Authors: Li Xiaoling , Xu Weiqing , Jia Huiying , Wang Xu , Zhao Bing , Li Bofu , Ozaki Yukihiro
Published: April 2004

A new surface-enhanced Raman scattering (SERS) active substrate has been developed based on our previous study. Small silver nanoparticles on a quartz slide can be enlarged by using a mixture of commercially available reagents called Silver Enhancer and Initiator. The optical properties and characteristics of the new substrate have been investigated by ultraviolet–visible (UV-Vis) spectroscopy and atomic force microscopy (AFM). The results indicate that the small silver nanoparticles grow and some silver aggregates emerge on the quartz slide after the slide is immersed into the Silver Enhancer and Initiator Mixture (SEIM). The average diameter of the silver nanoparticles on the substrate becomes approximately double after the immersion into SEIM for 20 s. 1,4-bis[2-(4-pyridyl)ethenyl]-benzene (BPENB) was used as a Raman probe to evaluate the enhancement ability of the new silver substrate. It has been found that the SERS intensity can be increased about 10 times by using the substrate treated by SEIM compared with that without being treated by SEIM. Interestingly enough, the SERS enhancement increases with time. This may be due to the reorganization of silver nanoparticles on the quartz surface. The new substrate can remain active for more than 90 days. The adsorption mode of BPENB on the new substrate and the dependence of the BPENB configurations on the concentration of BPENB in methanol solution have also been investigated by SERS or UV-Vis spectroscopy. The SERS spectra of a self-assembled monolayer (SAM) BPENB film adsorbed on a silver substrate treated by SEIM show that BPENB molecules are chemically absorbed through the Ag–N bond. Consequently, a nearly perpendicular orientation of BPENB on the silver surface is proposed. The SERS spectra of BPENB SAMs on the new substrates fabricated from methanol solutions with different concentrations are compared. The concentration dependence of the SERS spectra reveals that the BPENB molecules are adsorbed on the silver film as monomers when the film is prepared from the solution with a lower concentration (<4 × 10−6 M) and as aggregates when it is prepared from the solution with a higher concentration (>1 × 10−5 M).
Real-Time in situ Raman Analysis of Microwave-Assisted Organic Reactions
Authors: Pivonka Don E. , Empfield James R.
Published: April 2004

Integration of a Raman probe into a commercially available microwave synthesizer has demonstrated unprecedented utility in understanding chemical processes within the rapidly emerging field of microwave-assisted organic synthesis. The real-time spectral feedback afforded by this system has facilitated analysis of reaction mechanisms, reactive intermediates, and reaction kinetics via optical sampling through the sidewall of the sealed reaction vial within the microwave chamber. The feasibility, attributes, and limitations of the system are illustrated using amine coupling and Knoevenagel coupling example reactions. In addition to the reported analyses, this system provided the safety of remote sensing, adequate sensitivity, ease of alignment, and optimized “depth of field” for analysis of solutions with solids content.
Two Multivariate Strategies Applied to Three-Way Kinetic Spectrophotometric Data for the Determination of Mixtures of the Pesticides Carbaryl and Chlorpyrifos
Authors: Espinosa-Mansilla Anunciación , de la Peña Arsenio Muñoz , Goicoechea Héctor C. , Olivieri Alejandro C.
Published: April 2004

Two pesticides, carbaryl and chlorpyrifos, have been simultaneously determined using second-order kinetic spectrophotometric measurements upon alkaline oxidative degradation. In spite of the complexity of the system and of the serious spectral overlap among the reagents and products, calibration and prediction is possible thanks to the power of second-order multivariate techniques. Strategies such as parallel factor analysis (PARAFAC) and multivariate curve resolution coupled to alternating least-squares (MCR-ALS) have been employed, which adequately exploit the second-order advantage. They allow for a correct determination of the analytes both in synthetic binary samples and in a commercial formulation, in this latter case even in the presence of unmodeled interferents. Multi-way partial least-squares (n-PLS) produced good results only on synthetic binary mixtures but could not be applied to a commercial sample because it contained an uncalibrated component.
Determination of Phosphorous and Sulfur in Environmental Samples by Electrothermal Vaporization Inductively Coupled Plasma Atomic Emission Spectrometry
Authors: Okamoto Yasuaki , Kanda Kouichirou , Kishiwada Satoru , Fujiwara Terufumi
Published: April 2004

From the viewpoint of selective introduction of the analyte from its solvent and matrices, electrothermal vaporization (ETV) is useful for the sample introduction into the inductively coupled plasma (ICP). By using a tungsten boat furnace (TBF) vaporizer system, the loss of analyte phosphorus, which normally occurs during the drying and ashing stages, is suppressed. The phosphate ion is reacted with the tungsten supplied from the surface of the TBF to form stable tungsten phosphate species. Regarding the determination of sulfur, additional chemical modifiers such as copper(II), lead(II), etc., are necessary to retain the analyte on the TBF. The furnace-fusion (FF) method or wet-digestion technique on the TBF is applied to unify the chemical forms of the analytes. Various oxidative and reductive inorganic compounds as well as organic compounds of phosphorus and sulfur show the same sensitivities after the FF digestion with hydrogen peroxide. The detection limits are 1.5 ng and 0.12 ng for phosphorous and sulfur, respectively. The repeatabilities in terms of the relative standard deviations of 10 replicate measurements of phosphorus and sulfur are 4.2% and 2.0%, respectively. Finally, the established method is applied to the determination of several environmental waters.
Characterization of Supported Cylinder—Planar Germanium Waveguide Sensors with Synchrotron Infrared Radiation
Authors: Vongsvivut Jitraporn , Fernandez Jason , Ekgasit Sanong , Braiman Mark S.
Published: April 2004

Cylinder–planar Ge waveguides are being developed as evanescent-wave sensors for chemical microanalysis. The only non-planar surface is a cylinder section having a 300-mm radius of curvature. This confers a symmetric taper, allowing for direct coupling into and out of the waveguide's 1-mm2 end faces while obtaining multiple reflections at the central <30-μm-thick sensing region. Ray-optic calculations indicate that the propagation angle at the central minimum has a strong nonlinear dependence on both angle and vertical position of the input ray. This results in rather inefficient coupling of input light into the off-axis modes that are most useful for evanescent-wave absorption spectroscopy. Mode-specific performance of the cylinder–planar waveguides has also been investigated experimentally. As compared to a blackbody source, the much greater brightness of synchrotron-generated infrared (IR) radiation allows a similar total energy throughput, but restricted to a smaller fraction of the allowed waveguide modes. However, such angle-selective excitation results in a strong oscillatory interference pattern in the transmission spectra. These spectral oscillations are the principal technical limitation on using synchrotron radiation to measure evanescent-wave absorption spectra with the thin waveguides.
Determination of the Molecular Orientation of Poly(Propylene Terephthalate) Fibers Using Polarized Raman Spectroscopy: A Comparison of Methods
Authors: Frisk S. , Ikeda R. M. , Chase D. B. , Rabolt J. F.
Published: April 2004

For the first time, four different methods to determine the degree of molecular orientation from polarized Raman spectroscopy measurements are compared. The great influence of molecular orientation on the properties of polymers has driven the development of multiple experimental techniques and procedures. This study is based on the C1–C4 ring stretching vibration of poly(propylene terephthalate) (PPT) at 1614 cm−1. It is shown that simply ratioing the band intensity obtained with the polarization parallel and perpendicular to the unique axis of the sample provides a good qualitative method to observe the evolution of orientation in a series of similar samples. To quantitatively compare the degree of orientation one needs to utilize a more complex method yielding the second- and fourth-order parameters of the orientation distribution function ( P2 and P4, respectively). To date, most studies have been based on the assumption of a cylindrically symmetric polarizibility tensor. It is shown that this assumption is highly questionable although this method has been used fairly successfully in the past. This method results in orientation parameters that are clearly different from those obtained with the two more complex procedures. The most complex method, both theoretically and experimentally, requires the most measurements per sample. Major problems have occurred when trying to calculate the desired parameters, in particular for samples with high birefringence. These problems are related to experimental complexities occurring for measurements when the samples are tilted with respect to the polarization direction of the incident light. These measurements are replaced by a simple determination of depolarization ratio in the third method. This method assumes that the depolarization ratio is independent of changes in molecular orientation and structure. It was found that this assumption is not correct. Thus, the most complex method is the method of choice to quantitatively determine the second- and fourth-order parameters of the orientation distribution function, unless one has knowledge of the depolarization ratio of each sample being studied. That knowledge permits the use of an experimentally simpler method to obtain the desired parameters.
Surface-Enhanced-Raman-Scattering-Inducing Nanoprobe for Spectrochemical Analysis
Authors: Stokes David L. , Chi Zhenhuan , Vo-Dinh Tuan
Published: April 2004

This paper describes a new nanoprobe that induces the surface-enhanced Raman scattering (SERS) effect when brought into contact with chemicals on any type of surface. The SERS-inducing probe was fabricated from an optical fiber that was tapered to a tip 100 nm in diameter. A thin layer of silver islands was applied to the tip of the tapered fiber via thermal evaporation to induce the SERS effect. The small scale of the tip may be amenable to localized, nondestructive SERS-based analyses of surfaces with high spatial selectivity. Because the contact probe itself induces the SERS effect, no modification of the sample is required. Direct analysis at submicrometer spatial selectivity is therefore possible for analyte compounds on any type of surface. Various optimization studies and preliminary evaluations were performed. A 10-nm silver thickness was determined to yield the optimum SERS effect. A 25% relative standard deviation in SERS signal was observed for five different probe tips. As a demonstration of the SERS-inducing capability of the probe, Raman spectra were recorded for glass surfaces coated with brilliant cresyl blue and p-aminobenzoic acid before and during contact with the SERS-inducing nanoprobe.
Application of Magnetic Resonance Imaging to the Investigation of the Diffusivity of 1,1,1,2-Tetrafluorethane in Two Polymers
Authors: Mayele M. , Oellrich L. R.
Published: April 2004

In order to evaluate the suitability of a polymer as a sealing material for certain working fluids used in process plants, information about the fluid diffusivity into the polymer or the polymer permeability to the fluid is a prerequisite. The fluid of interest in the present work is 1,1,1,2-tetrafluorethane, CH2FCF3, a partly fluorinated hydrocarbon (HFC) commonly known as refrigerant R134a. HFCs are increasingly used in refrigeration, air conditioning, and heat pump applications as substitutes for the chlorofluorocarbons (CFCs) or hydrochlorofluorocarbons (HCFCs) that are believed to be responsible for ozone depletion in the stratosphere. The polymers studied were FPM, a perfluoroelastomer, and EPDM, an ethylenepropylene-diene rubber. The study was carried out using magnetic resonance imaging (MRI). The contact time dependence of diffusion of the fluid into the polymer, as well as the spatial distributions of spin–lattice, T1, and spin–spin, T2, relaxation times, were used as indicators of the influence of the EPDM matrix on the mobility of R134a molecules.
Fourier Transform Infrared Spectral Analysis of Degenerative Cartilage: An Infrared Fiber Optic Probe and Imaging Study
Authors: West P. A. , Bostrom M. P. G. , Torzilli P. A. , Camacho N. P.
Published: April 2004

A preliminary investigation into the diagnostic potential of an infrared fiber optic probe (IFOP) for evaluating degenerative human articular cartilage is described. Twelve arthritic human tibial plateaus obtained during arthroplasty were analyzed using the IFOP. Infrared spectra were obtained from IFOP contact with articular surface sites visually graded normal or degraded (Collins Scale grade 1 and grade 3, respectively). Comparisons of infrared spectral parameters (peak heights and areas) were made to elucidate spectral indicators of surface degeneration. IFOP spectral analysis revealed subtle but consistent changes between grades 1 and 3 sites. Infrared absorbance bands arising from type II collagen were observed to change with degradation. More degraded tissues exhibited increased amide II (1590–1480 cm−1)/1338 cm−1 area ratio ( p = 0.034) and decreased 1238/1227 cm−1 peak ratio ( p = 0.017); similar changes were seen with Fourier transform infrared imaging spectroscopy (FT-IRIS) analysis. Grades 1 and 3 cartilage showed consistent spectral differences in the amide II, III, and 1338 cm−1 regions that are likely related to type II collagen degradation that accompanies cartilage degeneration. These results suggest that it may be possible to monitor subtle changes related to early cartilage degeneration, allowing for IFOP use during arthroscopy for in situ determination of cartilage integrity.
Characterization of Infrared Matrix-Assisted Laser Desorption Ionization Samples by Fourier Transform Infrared Attenuated TotalReflection Spectroscopy
Authors: Laboy Jorge L. , Murray Kermit K.
Published: April 2004

Fourier transform infrared attenuated total reflection (FT-IR ATR) spectroscopy was used to characterize thin films of succinic acid, a matrix compound commonly used with infrared matrix-assisted laser desorption ionization (IR-MALDI) mass spectrometry. IR spectra of succinic acid thin films deposited alone and in combination with the analyte biomolecules insulin and cytochrome c were obtained by FT-IR ATR spectroscopy. Spectra of analyte and matrix alone were similar to those obtained previously from KBr pellets, Nujol mull, or thin-film absorption, although the ATR spectra have significantly lower background interferences. Thin films deposited from mixtures of water and methanol have additional peaks compared to films deposited from a methanol solution. These additional peaks are attributed to carboxylate groups stabilized by residual water molecules. No evidence was found to suggest that residual water absorption contributes to absorption at wavelengths typically used for IR-MALDI. Absorption of energy by analyte vibrational modes with rapid energy transfer to the matrix is suggested as a contributor to desorption and ionization consistent with the FT-IR ATR results.
Synaptic Responses to Whisker Deflections in Rat Barrel Cortex as a Function of Cortical Layer and Stimulus Intensity
Authors: Wilent W. Bryan , Contreras Diego
Published: April 2004

To study the synaptic and spike responses of barrel cortex neurons as a function of cortical layer and stimulus intensity, we recorded intracellularlyin vivofrom barbiturate anesthetized rats while increasing the velocity-acceleration of the whisker deflection. Granular (Gr; layer 4) cells had the EPSP with the shortest peak and onset latency, whereas supragranular (SGr; layers 2-3) cells had the EPSP with longest duration and slowest rate of rise. Infragranular (Igr; layers 5-6) cells had intermediate values, and thus each layer was unique. The spike response peak of Gr cells was followed by IGr and then by SGr cells. In all cells, depolarization reduced the duration and amplitude of the response, but only in Gr cells did it reveal an early IPSP that cut short the EPSP. This early IPSP was associated with a large decrease in input resistance and an apparent reversal potential below spike threshold; consequently, synaptic integration in Gr cells was limited to the initial 5-7 msec of the response. In contrast, in SGr and IGr cells, results suggest an overlap in time of the EPSP and IPSP, with a small drop in input resistance and an apparent reversal potential above spike threshold, facilitating input integration for up to 20 msec. Decreasing stimulus intensity (velocity-acceleration) reduced the amplitude and increased the peak latency of the response without altering its synaptic composition. We propose that layer 4 circuits are better suited to perform coincidence detection, whereas supra and infragranular circuits are better designed for input integration.
Methoden der interferometrischen Formerfassung nicht-ruhender technischer Oberflächen (Methods for Interferometric Contour Measurement of Non Stationary Technical Surfaces)
Authors: Meixner Andreas , Purde Andreas , Schweizer Hans , Kirilenko Philipp , Riemenschneider Markus , Zeh Thomas , Koch Alexander W.
Published: April 2004

Die moderne Qualitätsprüfung technischer Oberflächen erfordert zunehmend berührungslose und zerstörungsfreie Messverfahren. Die Triangulation sowie die Weißlichtinterferometrie erfüllen hier die meisten Anforderungen bezüglich Messgenauigkeit. Zur Messung nicht-ruhender Objekte sind diese Verfahren jedoch meist nur begrenzt geeignet. Die Zwei-Wellenlängen-Speckle-Interferometrie bietet eine interessante Alternative für Einsatzgebiete, bei welchen besonders die Messzeit eine entscheidende Rolle spielt. Es wird ein Messsystem vorgestellt, das die simultane Aufzeichnung aller für die interferometrische Formerfassung notwendigen Daten ermöglicht und somit den Einfluss von Bewegungen weitgehend unterdrücken kann. Eine GPU-basierte (GPU = Graphic Processing Unit) Interferogramm-Auswertung ermöglicht eine hohe Messgeschwindigkeit und Messrate.
Selbstüberwachter Stellantrieb mit elektrochemischem Aktor (Self-Monitored Valve-Drive with Electrochemical Actuator)
Authors: Jelondz Dmitri , Horn Michael , Tränkler Hans-Rolf
Published: April 2004

Am Beispiel eines Heizkörper-Ventilantriebes wird ein neues Aktor-Sensor-System unter Nutzung eines elektrochemischen Aktors (ECA) und eines induktiven Positionssensors beschrieben. Aufgrund des pneumatischen Wirkprinzips können ECAs große Kräfte bei kleinem Volumen und geringem Energiebedarf lautlos bereitstellen. Über digitale Signalverarbeitung ist das System fähig, sich bei Inbetriebnahme selbst zu kalibrieren, während des Betriebs automatisch zu überwachen und zu rekalibrieren. Durch Kontrolle der wichtigsten Parameter des ECA, wie Ladespannung, Ladestrom und Hub sowie der Kennlinie des Positionssensors, können bevorstehende Ausfälle des Systems rechtzeitig erkannt werden.
Neuartige Regelung eines Coriolis-Massedurchflussmessers (A Novel Control Algorithm for Coriolis Mass Flowmeters)
Authors: Schröder Thorsten , Kolahi Kourosh , Röck Helmut
Published: April 2004

Coriolis-Massedurchflussmesser (CMD) zeichnen sich durch eine hohe Messgenauigkeit bei gleichzeitig kleiner Querempfindlichkeit gegenüber den Fluideigenschaften aus. Allerdings zeigt sich unter schwierigen Prozessbedingungen, insbesondere bei CMD mit einem einzigen geraden Messrohr, das Problem einer Änderung von Nullpunkt und Empfindlichkeit. In dieser Arbeit wird ein modellbasierter Ansatz zur On-line-Bestimmung dieser Kenngrößen des CMD vorgestellt. Er basiert auf der Kompensation sowohl der Corioliskräfte als auch der internen Kopplungen des CMD. Zur Realisierung des Kompensationsverfahrens wird eine neuartige Regelung, bestehend aus zwei kaskadierten Reglern, vorgestellt. Der äußere Regelkreis basiert auf einem Zeigerverfahren und einem optimalen Zustandsregler (LQ-Regler) für die Ausgangssignale des CMD. Der innere Kreis regelt die Phasendifferenz zwischen Ein- und Ausgangssignal des 1. Modes des Messrohres, indem die Antriebsfrequenz verstellt wird. Er gewährleistet den Betrieb des CMD in der Eigenfrequenz des 1. Modes.
X-ray reflectivity study of the influence of temperature fluctuations on the density profile of thin liquid films
Authors: Fendt Robert , Sprung Michael , Gutt Christian , Seeck Oliver Hermann , Tolan Metin
Published: April 2004

We report on X-ray reflectivity experiments of thin liquid heptane films. The films were examined using X-ray reflectivity and modelled both as a layered system using the Parratt algorithm and using a ´phase guessing´ inversion method. Our results combined with simulations of films of shrinking thickness show that small temperature instabilities during the investigation can cause artifacts in the electron density profile. These can easily be mistaken for density os cillations near the interface as might be expected for liquid molecules near a hard wall.
On the superstructure of KTiO2(OH)
Authors: Yang Qunbao B. , Wang Peiling L. , Li Yongxiang , Yin Qingrui R. , Werner Per-Erik , Moliterni Anna Grazia Giuseppina , Cheng Yi-Bing
Published: April 2004

The superstructure of potassium titanate, KTiO2(OH), prepared by hydrothermal synthesis has been determined from synchrotron powder diffraction data. It is shown that the unit cell of the superstructure is rhombohedral: a = 11.13848 Å, α = 52.7336°. The structure has been determined and refined in space group R3̅c to R
F = 0.074. The distribution of hydrogen atoms as hydroxy groups can be explained from the crystal structure described by the supercell.
J-aggregate structures in crystals of three bisazomethine dyes
Authors: Matsumoto Shinya , Shirai Kazuko , Kobayashi Kimiko , Wada Tatsuo , Shiro Motoo
Published: April 2004

The crystal structures of three bisazomethine dyes, which form J-aggregates in vapor-deposited films, were investigated. The characteristic two-dimensional arrangement of molecules proposed for J-aggregates was recognized in crystals of all three dyes. The observation of unusual bond lengths in one of the dyes at 298 K was resolved by a low temperature study, i.e. 93 K, that showed the existance of conformational disorder at the higher temperature.
Self‐monitoring of Blood Glucose
Authors: Skyler Jay S.
Published: April 2004

Self‐monitoring of blood glucose (SMBG) is an essential tool in the management of diabetes. If properly used, SMBG values are employed by the patient to make immediate treatment decisions. The decisions are based on a predetermined action plan that consists of actions designed to achieve blood glucose values within a given target range. Optimal treatment of diabetes is guided by the knowledge of prevailing blood glucose levels. SMBG is an essential component of any intensive therapy program directed toward achieving meticulous glycemic control. SMBG enables therapeutic goals to be clearly defined and permits assessment of glycemic control during ordinary life, thus being complementary to glycated hemoglobin measurements. SMBG determinations are used on an ongoing basis by patients, to aid in the adjustment of the therapeutic regimen. Optimal use of SMBG requires the goals of treatment to be clearly defined and for patients to be taught proper interpretation of the data. Patients need to learn how to use the data to adjust food intake, exercise, or pharmacological therapy to achieve specific glycemic goals. SMBG is the only practical means of detecting asymptomatic hypoglycemia in the outpatient setting. SMBG may also be used to detect temporal glycemic patterns, so that therapy may be modified in an attempt to prevent hypoglycemia. A great advantage of SMBG is its use in intercurrent illness and other emergency situations, in which SMBG allows objective documentation of acute destabilization of diabetic control. Patients may be provided with a home management plan to use during illness. SMBG may be particularly important in children and adolescents who have wide day‐to‐day variations in activity.

Instrumental to the use of SMBG is the choice of blood glucose targets. There should be defined blood glucose targets, individualized for the needs of each patient. Frequency of monitoring depends on the treatment program and varies considerably depending on the clinical situation. Knowledge of preprandial, bedtime, and nocturnal blood glucose concentrations is required to determine the appropriate basal and preprandial insulin doses. The best predictor of compliance with SMBG is the perception of improved control with such monitoring. Record keeping is essential to successful treatment, particularly if one is to consider the impact of previous responses. In response to blood glucose fluctuations, the patient must learn how to take appropriate action, predetermined with the diabetes management team.
Aging and Diabetes Mellitus
Authors: Sinclair Alan J.
Published: April 2004

Diabetes mellitus in older subjects is the commonest metabolic disorder and can have devastating consequences if left unchecked. Apart from the management of vascular complications, diabetes in the elderly requires attention to recognizing the often insidious onset of clinical depression, cognitive impairment, and the need to avoid where possible care home admission and debilitating metabolic decompensation. Specialist care for the vulnerable older adult with diabetes mellitus needs to be enhanced rather than sidelined into generalist care, and requires coordination of diabetes care between health and social services teams. Agreement on the goals of care is mandatory and should involve the patient and carer where appropriate. Geriatric diabetes is an exciting and challenging clinical discipline.
Formation and morphologies of ethylcyanoethyl cellulose/poly(ε‐caprolactone) blending films
Authors: Zhou Xuesong , Huang Yong
Published: April 2004

The texture of ethylcyanoethyl cellulose [(ECE)C]/poly(ε‐caprolactone) (PCL)/dichloroacetic acid (DCA) solutions and the morphology of the (ECE)C/PCL blending films were studied by polarizing optical microscope. The critical concentration of the (ECE)C/PCL/DCA solutions, at which the mesophase began to appear, was not influenced by the addition of PCL molecules, and the evolution of the cholesteric texture varied with different contents of PCL in the blends. Spherulites with a ringed extinction pattern in the (ECE)C/PCL blending films were formed below an (ECE)C concentration of 25 wt %. Moreover, the bright band distance of the alternative ringed extinction pattern decreased with increasing (ECE)C concentration. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 550–554, 2004
Effective nucleating chemical agents for the crystallization of poly(trimethylene terephthalate)
Authors: Zhang Jialiang
Published: April 2004

This study focused on the crystallization promotion of poly(trimethylene terephthalate) (PTT), with an aim at engineering thermoplastics applications. The effects of organic sodium (Na) salts, including Na stearate, Na benzoate, disodium‐p‐phenolsulfonate (2Na‐p‐PS), disodium‐p‐hydroxybenzoate (2Na‐p‐HB), and the sodium ionomer of poly(ethylene‐co‐methacrylic acid) (Na‐EMAA), were investigated as nucleating chemical agents with differential scanning calorimetry and capillary viscometry. For comparison, the effect of fine talc powder was also examined. The chemical agents were generally more effective than fine talc powder. Na stearate and Na benzoate caused large‐scale decomposition of PTT. 2Na‐p‐PS was quite thermally stable and caused little decomposition. 2Na‐p‐HB was the most efficacious of the nucleating chemical agents and caused mild decomposition. Na‐EMAA was the most thermally stable and induced an increase in melt viscosity. A remarkable improvement in the crystallization rate of PTT was successfully attained at a minimum polymer decomposition cost by the introduction of a suitable amount of 2Na‐p‐PS, 2Na‐p‐HB, or Na‐EMAA or by the concurrent proper incorporation of both of the latter two agents. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 590–601, 2004
The evolution of molecular genetic pathways and networks
Authors: Cork Jennifer M. , Purugganan Michael D.
Published: April 2004

There is growing interest in the evolutionary dynamics of molecular genetic pathways and networks, and the extent to which the molecular evolution of a gene depends on its position within a pathway or network, as well as over‐all network topology. Investigations on the relationships between network organization, topological architecture and evolutionary dynamics provide intriguing hints as to how networks evolve. Recent studies also suggest that genetic pathway and network structures may influence the action of evolutionary forces, and may play a role in maintaining phenotypic robustness in organisms. BioEssays 26:479–484, 2004. © 2004 Wiley Periodicals, Inc.
The Nature of Intermolecular CuI⋅⋅⋅CuIInteractions: A Combined Theoretical and Structural Database Analysis
Authors: Carvajal M. Angels , Alvarez Santiago , Novoa Juan J.
Published: April 2004

The nature of intermolecular interactions between dicoordinate CuIions is analyzed by means of combined theoretical and structural database studies. Energetically stable CuI⋅⋅⋅CuIinteractions are only found when the two monomers involved in the interaction are neutral or carry opposite charges, thus allowing us to speak of bonding between the components of the bimolecular aggregate. A perturbative evaluation of the components of the intermolecular interaction energies, by means the IMPT scheme of Stone, indicates that both the Coulombic and dispersion forces are important in determining the CuI⋅⋅⋅CuIbonding interactions, because only a small part of that energy is attributable to Cu⋅⋅⋅Cu interactions, while a large component results from Cu⋅⋅⋅ligand interactions. The electrostatic component is the dominant one by far in the interaction between charged monomers, while in the interaction between neutral complexes, the electrostatic component is found to be of the same order of magnitude as the dispersion term. Bimolecular aggregates that have like charges are repulsive by themselves, and their presence in the solid state results from anion⋅⋅⋅cation interactions with ions external to this aggregate. In these cases, the short‐contact Cu⋅⋅⋅Cu interactions here should be more properly called counterion‐mediated Cu⋅⋅⋅Cu bonds.
Surface‐Confined Single Molecules: Assembly and Disassembly of Nanosize Coordination Cages on Gold (111)
Authors: Menozzi Edoardo , Pinalli Roberta , Speets Emiel A. , Ravoo Bart Jan , Dalcanale Enrico , Reinhoudt David N.
Published: April 2004

A cavitand functionalized with four alkylthioether groups at the lower rim, and four tolylpyridine groups on the upper rim is able to bind to a gold surface by its thioether groups, and forms a coordination cage with [Pd(dppp)(CF3SO3)2] by its pyridine groups. The cavitand or the cage complex can be inserted from solution into a self‐assembled monolayer (SAM) of 11‐mercaptoundecanol on gold. The inserted molecules can be individually detected as they protrude from the SAM by atomic force microscopy (AFM). The cages can be reversibly assembled and disassembled on the gold surface. AFM can distinguish between single cavitand and cage molecules of 2.5 nm and 5.8 nm height, respectively.
Metallosupramolecular Zippers Generated by Self‐Organization of Self‐Complementary Molecular Clefts
Authors: Barboiu Mihail , Petit Eddy , Vaughan Gavin
Published: April 2004

The binding of Co2+ and Pb2+ ions to the terpyridine and pyridine subunits of the ligand 1 leads to the self‐complementary molecular clefts 2–6, which result from the crossover combination of orthogonal‐terpyridine and linear‐pyridine metal‐coordination subprograms and are stabilized by strong π–π stacking interactions. Four different cleft‐type entities, [Co2+2(1)2] (3), [Pb2+2(1)2] (4), [Co2+4(1)2] (5), [Pb2+4(1)2] (6), are generated in both solution and the solid state, and may be interconverted as a function of metal/ligand stoichiometry. One‐ and two‐dimensional metallosupramolecular zipper architectures result from self‐assembly in the solid state driven by a combination of different π–π stacking subprograms. The U‐shaped geometry of the ligand influences the possibility of zipping and thus, in turn, the generation of different zipper architectures. The structures of 2–5 have been confirmed by X‐ray crystallography; that of 6 is based on NMR spectral data.
Preparation and Crystal Structure of Ni16Si9Al.
Authors: Richter Klaus W. , Prots Yurii , Grin Yuri
Published: April 2004

For Abstract see ChemInform Abstract in Full Text.
Bimetallic Catalysts for the Efficient Growth of SWNTs on Surfaces.
Authors: Wang Xuan , Yue Wenbo , He Maoshuai , Liu Manhong , Zhang Jin , Liu Zhongfan
Published: April 2004

For Abstract see ChemInform Abstract in Full Text.
Catalytic Hydrogenation of Acetophenone with Hydrogen Transfer over Chiral Diamine Rhodium(I) Complexes.
Authors: Nindakova L. O. , Shainyan B. A. , Belonogova L. N.
Published: April 2004

For Abstract see ChemInform Abstract in Full Text.
Oxidation of Alcohols Using (NH4)2Cr2O4 in the Presence of Al(HSO4)3 and Wet SiO2.
Authors: Shirini Farhad , Zolfigol Mohammad A. , Abedini Masoumeh , Salehi Peyman
Published: April 2004

For Abstract see ChemInform Abstract in Full Text.
One‐Pot Synthesis of α‐Bromoesters and Ketones from β‐Ketoesters and Diketones Using Supported Reagents System.
Authors: Aoyama Tadashi , Takido Toshio , Kodomari Mitsuo
Published: April 2004

For Abstract see ChemInform Abstract in Full Text.
Ionic Liquid Enable Sulfamoylation of Arenes: An Ambient, Expeditious and Regioselective Protocol for Aryl Sulfonamides.
Authors: Naik Prashant U. , Harjani Jitendra R. , Nara Susheel J. , Salunkhe Manikrao M.
Published: April 2004

For Abstract see ChemInform Abstract in Full Text.
Syntheses of Oxazolidinone, Imidazolidinone and Thiazolidinone Derivatives Using a Polymer‐Supported Diphenylphosphoryl Azide.
Authors: Lu Yuhua , Taylor Richard T.
Published: April 2004

For Abstract see ChemInform Abstract in Full Text.
Reactions of γ‐Sultines with Electrophilic Reagents. Part 4. Chlorination of 5‐(4‐Methoxyphenyl)‐3‐phenyl‐1,2‐oxathiolane 2‐Oxide.
Authors: Grigor'ev E. V. , Saginova L. G. , Kleimenova I. Yu.
Published: April 2004

For Abstract see ChemInform Abstract in Full Text.
Palladium‐Catalyzed Carbonylation of Polychlorinated Pyridines. A Simple Laboratory Approach to Metal Catalyzed Carbonylation Reactions.
Authors: Hull John W. Jr. , Wang Chen
Published: April 2004

For Abstract see ChemInform Abstract in Full Text.
New Synthesis of 1,2,3,6,7,11b‐Hexahydro‐4H‐pyrimido[6,1‐a]isoquinolin‐4‐ones and 2,3,6,7,12,12b‐Hexahydropyrimido[1′,6′:1,2]pyrido [3,4‐b]indol‐4(1H)‐ones.
Authors: Fisyuk Alexander S. , Mukanov Alexei Yu. , Novikova Elena Yu.
Published: April 2004

For Abstract see ChemInform Abstract in Full Text.
Condensation of 5‐Aminopyrazoles Unsubstituted in Position 1 with β‐Keto Esters.
Authors: Nam N. L. , Grandberg I. I. , Sorokin V. I.
Published: April 2004

For Abstract see ChemInform Abstract in Full Text.
Configurationally Stable Axially Chiral N,N′‐Dialkyl‐2,2′‐biphenylene‐N,N′‐ureas.
Authors: Roshchin Alexander I. , Kostyanovsky Remir G.
Published: April 2004

For Abstract see ChemInform Abstract in Full Text.
Metastable States in Bismuth‐Containing Oxide Systems
Authors: Zhereb V. P. , Skorikov V. M.
Published: April 2004

For Abstract see ChemInform Abstract in Full Text.
Marine Natural Products
Authors: Blunt John W. , Copp Brent R. , Munro Murray H. G. , Northcote Peter T. , Prinsep Michele R.
Published: April 2004

For Abstract see ChemInform Abstract in Full Text.
Chemical Mediation of Interactions Among Marine Organisms
Authors: Paul Valerie J. , Puglisi Melany P.
Published: April 2004

For Abstract see ChemInform Abstract in Full Text.
Asymmetric Cycloisomerization of 1,6‐ and 1,7‐Enynes by Transition‐Metal Catalysts
Authors: Fairlamb Ian J. S.
Published: April 2004

For Abstract see ChemInform Abstract in Full Text.
Zinc—Nucleic Acid Interaction
Authors: Aoki Shin , Kimura Eiichi
Published: April 2004

For Abstract see ChemInform Abstract in Full Text.
A reliability growth model for modular software
Authors: Okamura Hiroyuki , Kuroki Shingo , Dohi Tadashi , Osaki Shunji
Published: April 2004

This paper presents a probabilistic model for evaluating the reliability of software having modular structure. In particular, it proposes a new reliability‐evaluating model based on the structure of software by integrating the Jelinski–Moranda model, which is the most basic black box model, and the Littlewood model, which is a representative white box model. The performance of the proposed model is compared and studied in reference to the benchmark model of Cheung and the dependency of the architecture and the reliability growth in software reliability evaluation is discussed. © 2004 Wiley Periodicals, Inc. Electron Comm Jpn Pt 2, 87(5): 43–53, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjb.20075
Allele‐specific loss of heterozygosity at the DAL‐1/4.1B (EPB41L3) tumor‐suppressor gene locus in the absence of mutation
Authors: Kittiniyom Kanokwan , Mastronardi Michelle , Roemer Martha , Wells Wendy A. , Greenberg E. Robert , Titus‐Ernstoff Linda , Newsham Irene F
Published: April 2004

DAL‐1/4.1B (EPB41L3)is a member of the protein 4.1 superfamily, which encompasses structural proteins that play important roles in membrane processes via interactions with actin, spectrin, and the cytoplasmic domains of integral membrane proteins. DAL‐1/4.1B localizes within chromosomal region 18p11.3, which is affected by loss of heterozygosity (LOH) in various adult tumors. Reintroduction of this protein into DAL‐1/4.1B‐null lung and breast tumor cell lines significantly reduced the number of cells, providing functional evidence that this protein possesses a growth suppressor function not confined to a single cell type. For characterization of the mutational mechanisms responsible for loss of DAL‐1/4.1B function in tumors, the exon–intron structure of DAL‐1/4.1B was examined for mutations in 15 normal/tumor pairs of non–small cell lung carcinoma by single‐strand conformation polymorphism analysis. These studies revealed that small intragenic mutations are uncommon in DAL‐1/4.1B. Furthermore, LOH analysis on 129 informative early‐stage breast tumors utilizing a new intragenic C/T single‐nucleotide polymorphism in exon 14 revealed that LOH resulted in preferential retention of the C‐containing allele, suggesting that allele‐specific loss is occurring. These studies indicate that mechanisms such as imprinting or monoallelic expression in combination with loss of heterozygosity may be responsible for loss of the DAL‐1/4.1B protein in early breast disease. © 2004 Wiley‐Liss, Inc.
Reduced dermatopontin expression is a molecular link between uterine leiomyomas and keloids
Authors: Catherino William H. , Leppert Phyllis C. , Stenmark Matthew H. , Payson Mark , Potlog‐Nahari Clariss , Nieman Lynnette K. , Segars James H.
Published: April 2004

Uterine leiomyomas are prevalent estrogen‐responsive clonal tumors, but the specific genetic alterations that contribute to their development have not been elucidated. To identify genes involved in the formation of leiomyomas, we used global expression profiling to compare clonal tumors with normal myometrium. Contrary to expectation, genes involved in estrogen action were not differentially expressed between leiomyoma and normal myometrium. Genes encoding extracellular‐matrix proteins were prominently featured, suggesting their involvement in formation of a myofibroblast phenotype. Analysis of the extracellular matrix in the leiomyomas revealed a disordered collagen fibril orientation. Expression of the collagen‐binding protein dermatopontin was found to be consistently decreased in leiomyoma by both reverse transcriptase–polymerase chain reaction (RT‐PCR) and real‐time RT‐PCR (mean underexpression = 9.41‐fold) regardless of leiomyoma size, leiomyoma location, patient race, and patient age. This expression pattern was observed in 11 subjects and a total of 23 leiomyoma:myometrium pairs. Decreased expression of dermatopontin was also associated with keloid formation, a fibrotic disease that shares epidemiologic similarities with leiomyoma. Immunohistochemical studies of leiomyomas and keloids demonstrated reduced levels of dermatopontin in both tissues. In addition, ultrastructural analysis revealed that the orientation of the collagen fibrils in the keloid tissues strongly resembled that in the leiomyomas. Reduction in dermatopontin was associated with an increase in transforming growth factor–β3 (TGFB3) mRNA levels in leiomyomas, whereas other genes involved in dermatopontin signaling were not differentially expressed. These findings suggest that leiomyoma development involves a myofibroblast cell phenotype characterized by dysregulation of genes encoding extracellular‐matrix proteins. In particular, decreased expression of dermatopontin represents a molecular link between the leiomyoma and keloid phenotypes. © 2004 Wiley‐Liss, Inc.