bluuebunny/crossref_metadata_2025 huggingface dataset:
New Instrumentation for Use in Excitation-Emission Fluorescence-Polarization Measurements
Authors: Destrampe Kevin A. , Hieftje Gary M.
Published: July 2005

A fluorescence excitation-emission matrix (EEM) is an excellent way to determine a specific substance in a multicomponent sample. In the present investigation, a novel, rapid-scanning spectrofluorometer has been developed for measuring an EEM; the instrument employs a 0.35-meter monochromator for choosing the excitation wavelength and a continuously variable interference filter for selecting the emission wavelength. With the system, a 51 × 93 excitation-emission matrix can be collected in 3.2 min, and detection limits of 500 ng/L are obtained for fluorescein dye in ethanol. Fluorescence polarization measurements in the plane parallel and perpendicular to the polarized excitation light adds another dimension to the instrument for characterizing a sample. The instrument is controlled by an IBM XT computer although data analysis is performed on a Macintosh computer with Spyglass software. A series of two-dimensional contour plots and multidimensional excitation-emission-polarization plots can be rapidly generated.
Determination of Silicone in Breast Tissue by Graphite Furnace Continuum Source Atomic Absorption Spectrometry
Authors: Wichems D. N. , Calloway Clifton P. , Fernando Reshan , Jones Bradley T. , Morykwas Michael J.
Published: July 2005

A method has been developed for the determination of silicone in breast tissue samples using a graphite furnace continuum source atomic absorption spectrometer. Silicone was measured as Si present in a heptane extract of the dried tissue samples. Thirty tissue samples were examined from 16 women having silicone gel-filled breast implants. Concentrations of Si in the dried tissue samples ranged from below the method detection limit of 3 ppm, to 6%.
Determination of Cadmium in Urine by Continuum Source Atomic Absorption Spectrometry
Authors: Fernando Reshan , Jones Bradley T. , Ennever Fanny K.
Published: July 2005

A graphite furnace continuum source atomic absorption spectrometric method is described for the determination of Cd in urine at the sub-ppb level. Sample preparation includes a simple 1:1 dilution with nitric acid followed by digestion in a water bath at 60°C for one hour in a sealed plastic vial. The method detection limit observed for Cd is 0.03 ng/mL. Three hundred urine samples collected from post-menopausal women in the Winston-Salem area have been analyzed.
Effect of Laser Energy and Atmosphere on the Emission Characteristics of Laser-Induced Plasmas
Authors: Kuzuya Mikio , Matsumoto Hitoshi , Takechi Hideaki , Mikami Osamu
Published: July 2005

The effects of laser energy and atmosphere on the emission characteristics of laser-induced plasmas were studied with the use of a Q-switched Nd: YAG laser over a laser energy range of 20 to 95 mJ. Argon, helium, and air were used as surrounding atmospheres, and the pressures were changed from atmospheric pressure to 1 Torr. The experimental results showed that the maximum spectral intensity was obtained in argon at around 200 Torr at a high laser energy of 95 mJ, whereas the line-to-background ratio was maximized in helium at around 40 Torr at a low energy of 20 mJ. The results are discussed briefly on the basis of the temporal and spatial observations of the laser-induced plasmas.
Characterization of Aspen Explosion Pulp by CP/MAS 13C NMR
Authors: Hua X. , Capretti G. , Focher B. , Marzetti A. , Kokta B. V. , Kaliaguine S.
Published: July 2005

Steam explosion pulps were studied by means of CP/MAS 13C NMR spectroscopy. The steam explosion treatment of aspen chips with Na2SO3 and Na2SO3 + NaOH led to a loss in hemicellulose and an increase in cellulose crystallinity. No lignin dissolution occurred during explosion pulping, although the lignin structure might have changed to a certain extent. For comparison purposes, conventional CMP and CTMP pulps were also analyzed. The conventional treatments revealed less modification in the spectrum with regard to original wood samples.
Breakdown Voltage Scaling Characteristics of an Argon Hollow Cathode Discharge
Authors: Mixon P. D. , Griffin S. T. , Williams J. C.
Published: July 2005

Paschen curves are presented for hollow cathodes with diameters varying from 5 mm to 1.5 mm. The curves obey similar functions of ( pd), where p is the argon gas pressure and d is the hollow diameter. The curves exhibit similar properties in terms of the location of the breakdown voltage minima. The breakdown voltage increases monotonically for decreasing hollow diameter. The shapes of the various curves and the ( pd) minima location are unaffected by aspect ratio.
Thermophysical Measurements and Interfacial Adhesion Studies in Ultrathin Polymer Films Using Homodyne Photothermal Spectrometry
Authors: Prystay M. C. , Power J. F.
Published: July 2005

Homodyne laser photopyroelectric spectrometry (PPES) is a new photothermal detection scheme which uses electronic mixing to downshift a high-frequency swept wave photothermal response into a bandwidth of approximately one kilohertz. A rapid photopyroelectric impulse response is recovered from the downshifted component at high time resolution and is used, here, in two different geometries, to probe the thermal and interfacial properties of assemblies composed of submicron-thick-ness polymer films deposited on the metallized surface of a pyroelectric thin-film detector. In the thermal transmission mode geometry, the sample is excited by irradiation in a very thin opaque surface layer, and the transit time of a heat pulse through the sample to the pyroelectric transducer can be used to obtain a thickness or thermal diffusivity measurement. By the use of an inverse mode geometry, a metal/polymer interface is excited by irradiation of an optically transparent polymer thin-film sample attached to the metallized surface of the pyroelectric transducer. Heat flow at short distances from the bond interface can be monitored by the pyroelectric effect through the high time resolution of the homo-dyne photopyroelectric measurement. The combination of information obtained in these two geometries with an analysis of the thermal wave reflections which occur at interfaces between materials of dissimilar thermal effusivity can be used to evaluate relative interfacial adhesion between the metal and polymer layer.
Super-Dynamic-Range and Super-Quantization Methods for FT-IR Spectra
Authors: Minami Kei-Ichiroh , Okayama Hiroaki , Kawata Satoshi
Published: July 2005

Numerical methods are proposed for expanding the dynamic range and increasing the quantization resolution of Fourier transform infrared spectrum data. In these methods, an interferogram is oversampled at a rate higher than the Nyquist sampling rate. From the oversampled interferogram data, the full-range interferogram or the lost quantization bits are recovered by using the Gerchberg-Papoulis iterative algorithm, incorporating constraints on the amplitude range of the interferogram and on the band limitation and non-negativity of the spectrum. Experimental results for IR absorption spectra of cyclohexene are shown in order to demonstrate the capabilities of the methods.
Near-Infrared Reflectance Spectroscopy: Different Strategies for Local Calibrations in Analyses of Forage Quality
Authors: Aastveit Are Halvor , Marum Petter
Published: July 2005

This paper deals with the problem of how to utilize a large calibration set with 10 different analytes in order to make the best predictions possible on a routine basis. Ten different strategies of using the data set were studied with the use of numbers of principal components ranging from 4 to 12. We found positive effects of scatter correction for most of the analytes. On average, the local regression methods were superior to the others. The optimum number of samples for local regression seems to be between 50 and 100. The largest reduction in root mean square error of prediction (RMSEP), in comparison to results for the traditional method, was found on scatter-corrected spectra and a proposed local calibration with 50 calibration samples. The gain in RMSEP for neutral detergent fiber (NDF), acid detergent fiber (ADF), and crude fiber was about 25% and for protein and in vitro digestible dry matter digestibility (IVDMD) about 10%, compared to results for the traditional universal calibration method.
Thermal Processing of o-Terphenyl: A Raman Study
Authors: Biswas A.
Published: July 2005

Raman spectra from o-terphenyl sealed in glass capillary tubes were acquired over temperatures ranging from 233 K to 343 K. Over this temperature range, o-terphenyl can exist in the solid-crystalline, molten, supercooled-liquid, and amorphous-glassy states. Representative structure-sensitive spectra are presented along with a qualitative description. The lattice spectral feature occurring at a Raman shift of 123 cm−1 displays abrupt changes in profile and intensity as melting and glass transition occur. The intensity ratio of the C-C stretching 996-cm−1 line and C-H stretching line at 1008 cm−1 displays a change related to the transformation of the ordered-crystalline phase to the disordered-liquid or glassy state. At a Raman shift of 1162 cm−1 the solid-crystalline state shows a splitting due to the effect of the crystal field. The possibility of using these structure-sensitive Raman characteristics for in situ diagnostics during materials processing is discussed.
Multivariate Determination of Sugar Powders by Attenuated Total Reflectance Infrared Spectroscopy
Authors: Dupuy N. , Meurens M. , Sombret B. , Legrand P. , Huvenne J.P.
Published: July 2005

Thanks to what has been achieved by Fourier transformation, infrared analysis can now become a state-of-the-art device in quality control laboratories if we consider its precision and the gain in time it ensures. Moreover, an increasing number of new mathematical regression methods such as partial least-squares (PLS) regression allow multicomponent quantitative analysis in mixtures. Nevertheless, the efficiency of infrared spectrometry as a quantitative analytical method often depends on the choice of an adequate presentation for the sample. For quantitative analysis of powders, sampling appears difficult in the mid-IR. We have developed a method built on three advantages: the rapidity of Fourier transform spectroscopy, fast solvent elimination, and good peak resolution. For enhancing peak intensity on attenuated total reflectance (ATR) spectroscopy we use nondissolving and evaporating liquids. For instance, the analysis of three components (glucose, fructose, and sucrose) can be done with a precision in the range of 4%, whereas the time required to obtain an analysis report is about 5 min.
Detection of Silicone in Lymph Node Biopsy Specimens by Near-Infrared Raman Spectroscopy
Authors: Frank Christopher J. , McCreery Richard L. , Redd Douglas C. B. , Gansler Ted S.
Published: July 2005

Near-infrared Raman spectroscopy with a 782-nm cw laser was used to examine lymph node biopsy specimens from women with ruptured breast implants containing silicone gel. For reduction of fluorescence and sample radiation damage, a low-power (30 mW) Ti: sapphire laser, single-stage spectrograph, and CCD detector were employed. Silicone Raman features were clearly visible in lymph node tissue of patients with leaking implants, and the spectra were easily distinguished from those of normal lymph node tissue. The technique has promise for medical diagnostic purposes, and may be amenable to in vivo analysis with adaptation to a fiber-optic probe.
Laser-Excited Synchronous Luminescence Spectroscopy
Authors: Stevenson Christopher L. , Vo-Dinh Tuan
Published: July 2005

The use of lasers as excitation sources for molecular luminescence often results in improvements in sensitivity and limits of detection (LODs). Synchronous luminescence (SL) spectroscopy, in which both excitation and emission wavelengths are scanned simultaneously, provides a convenient means to improve selectivity (often dramatically) in the analysis of multicomponent mixtures using room-temperature luminescence. We report here on the first use of a dye laser as an excitation source for SL at room temperature. The performance of the laser synchronous luminescence (LSL) system is described for the analysis of four polyaromatic compounds; for one of these—tetracene—the LOD was 680 zeptomoles (10−21 mol) in the volume probed by the laser. In addition to impressive sensitivity and selectivity, the laser system used is quite small and can be considered as an attractive source for portable SL instruments designed for in-field screening of environmental samples.
Picosecond Raman Spectroscopy Using a Streak Camera
Authors: Tahara Tahei , Hamaguchi Hiro-O
Published: July 2005

A Raman measuring system using a streak camera has been constructed. This system consists of a picosecond pulsed laser, an astigmatism-corrected spectrograph, and a streak camera. It enables two-dimensional multichannel detection (time and frequency) of Raman scattering with time resolution as high as 10 ps (without deconvolution). The system was first applied to fluorescence background rejection. Raman spectra of benzene containing a trace amount of Rhodamine 640 were measured. The improvement factor of the Raman-to-fluorescence intensity ratio was estimated as 281, compared with the time-integrated cw measurement. Second, the system was used for picosecond time-resolved Raman spectroscopy. Nanosecond probing laser pulses were used with picosecond pumping. Raman scattering at each delay time was time-resolved and detected by the streak camera. Time-resolved Raman spectra of benzophenone at delay times ranging from −1.25 ns to 1.5 ns were obtained from one single measurement. These results indicate that, if properly designed and properly combined with a suitable optical setup, a streak camera has very high potential for Raman spectroscopy.
Acoustic Monitoring of Carbon Film Formation by Laser-Induced Chemical Vapor Deposition
Authors: Iida Yasuo , Yeung Edward S.
Published: July 2005

Acoustic signals generated by the deposition of carbon thin films were monitored in situ by a microphone. Photolysis of benzene or adamantane vapor in the presence of helium buffer gas of 5 to 100 Torr by an ArF excimer laser formed several kinds of carbon films (e.g., polymeric, amorphous, and graphitic films), depending on the optical configuration, the ambient pressure, the laser fluence, and the reagent pressure. Analysis of the acoustic signal offers some insight into the mechanism of the deposition processes, which include the graphitization of the deposited films and the role of energetic particles, such as vibrationally excited benzene, in the deposition of amorphous hydrogenated carbon film. Also, the acoustic signal clearly showed the presence of surface-related processes in the course of film deposition.
Adsorption Kinetics of EGDN on ZnO by Diffuse Reflectance Infrared Fourier Transform Spectroscopy
Authors: Henderson D. O. , Silberman E. , Chen N. , Snyder F. W.
Published: July 2005

Diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) was used to follow the adsorption kinetics of ethyleneglycol dinitrate (EGDN) on zinc oxide as a function of dosing time. Inhomogeneous broadening of the NO2 antisymmetric stretching vibration was found to be dose dependent. Through nonlinear curve-fitting techniques, the sum of three component bands was found to reproduce the inhomogeneously broadened envelope and was attributed to two different types of adsorbed EGDN corresponding to on-end and bridged sites on a zinc rich surface of zinc oxide. The adsorbed EGDN species were characterized by their line-shape parameters and adsorption kinetics.
Contributions of Short-Range and Classical Electromagnetic Mechanisms to Surface-Enhanced Raman Scattering from Several Types of Biomolecules Adsorbed on Cold-Deposited Island Films
Authors: Sokolov Konstantin , Khodorchenko Peter , Petukhov Andrey , Nabiev Igor , Chumanov George , Cotton Therese M.
Published: July 2005

Surface-enhanced Raman scattering (SERS) spectra of three different classes of adsorbates have been analyzed: (1) native and denatured calf thymus DNA and adenine, as examples of molecules with electronic transitions in the UV region only; (2) flavine adenine dinucleotide (FAD) and doxorubicin (DOX), as examples of chromophores with low extinction transitions in the visible region; and (3) β-carotene, as an example of a chromophore with a very high extinction coefficient for an electronic transition in the visible region. These molecules were adsorbed on silver island films that had an extinction maximum in the 450–660 nm region of the electromagnetic spectrum. The short-range mechanism of Raman enhancement has been demonstrated to contribute primarily to enhanced Raman scattering from molecules in groups 1 and 2, whereas the pure (classical) electromagnetic mechanism dominates the enhancement of β-carotene resonance Raman scattering.
Color Analysis of the Brancacci Chapel Frescoes: Part II
Authors: Bacci M. , Baldini F. , Carlà R. , Linari R. , Picollo M. , Radicati B.
Published: July 2005

The restoration work of the frescoes in the Brancacci Chapel (Chiesa del Carmine, Firenze) offered us the opportunity of recording about one hundred reflectance spectra of selected areas on the frescoes before and after restoration. Our previous research was mainly devoted to pigment identification. In the present paper, color analysis is performed by computing chromaticity coordinates, purity, and dominant wavelength, starting from the reflectance spectra previously recorded. Afterwards, color difference between restored and not-restored fresco is evaluated and its distribution examined. The obtained results are then discussed in connection both to the causes which produced the color modification and to the possibility of performing electronic restoration on paintings.
Polarized Micro-Raman and FT-IR Spectra of L-Glutamine
Authors: Dhamelincourt P. , Ramirez F. J.
Published: July 2005

The infrared, Raman, and polarized micro-Raman spectra of the amino acid L-glutamine and its N,N'-d5 derivative in the crystalline state have been recorded and measured. The data obtained were used to propose a general assignment of the vibrational fundamentals on the basis of the intensity changes observed from the polarized Raman spectra, the iso-topic shifts measured from the deuterated isotopomer, and the correlations with frequencies assigned for other amino acids and related molecules.
NMR verification of single droplet freezing models
Authors: Hindmarsh J. P. , Wilson D. I. , Johns M. L. , Russell A. B. , Chen X. D.
Published: July 2005

Acquiring temporal solid/liquid fraction data of a freezing system is advantageous for verifying theoretical solidification models. Nuclear magnetic resonance (NMR) spectrometry was used to obtain liquid fraction data of droplets of either water or sucrose solution undergoing freezing. The data obtained were used to verify numerical models of this solidification process. For water droplets, good agreement was observed between the experimental and model predictions of the temporal change in the water fraction over the range of air temperatures studied, whereas for the sucrose solution good agreement was observed only at the highest air temperature. At lower air temperatures, the discrepancies of the model were attributed to the possible crystallization of sucrose at temperatures above its reported glass‐transition temperature. © 2005 American Institute of Chemical Engineers AIChE J, 2005
Thermal effects of CO2 absorption in aqueous solutions of 2‐amino‐2‐methyl‐1‐propanol
Authors: Camacho F. , Sánchez S. , Pacheco R. , Sánchez A. , La Rubia M. D.
Published: July 2005

In this work, the process of carbon dioxide absorption is analyzed at high partial pressures, in aqueous solutions of 2‐amino‐2‐methyl‐1‐propanol (AMP), with respect to the thermal effects involved. The experiments were carried out in a stirred tank reactor with a plane and known interfacial area. The variables considered were the AMP concentration and the temperature, within the ranges 0.1–3.0 kmol/m3 and 288–313 K, respectively. From the results, we deduce that the absorption process of pure carbon dioxide into aqueous solutions of AMP takes place in the instantaneous nonisothermal regime at low concentrations, whereas at high concentrations the regime may be fast. In the experiments at low amine concentrations, we propose an equation, which not only relates the experimental results to the initial amine concentration but at the same time enables the evaluation of the rise in temperature in the gas–liquid interface. From the results at high concentrations, we determined a reaction order of one with respect to the amine and an expression for the kinetic constant valid throughout the entire range of temperatures and concentrations assayed: k = 4.8 × 1012exp(−8186.9/T). © 2005 American Institute of Chemical Engineers AIChE J, 2005
Cover Picture: Reaction Progress Kinetic Analysis: A Powerful Methodology for Mechanistic Studies of Complex Catalytic Reactions (Angew. Chem. Int. Ed. 28/2005)
Authors: Blackmond Donna G.
Published: July 2005

The London Eye moves continuously even as passengers embark and disembark, serving as both a backdrop and a metaphor for a steady‐state catalytic cycle. The theme of the Review by D. G. Blackmond on page 4302 ff. is the mechanistic study of complex catalytic reactions using reaction progress kinetic analysis. A new set of graphical tools are described that are based on reaction monitoring in situ with simple data manipulations. Photo: ArtoftheState.co.uk.
Synthesis of 6‐(3,5‐Dichlorobenzyl) Derivatives as Isosteric Analogues of the HIV Drug 6‐(3,5‐Dimethylbenzyl)‐1‐(ethoxymethyl)‐5‐isopropyluracil (GCA‐186)
Authors: Sørensen Esben R. , El‐Brollosy Nasser R. , Jørgensen Per T. , Pedersen Erik B. , Nielsen Claus
Published: July 2005

The HIV‐1 inhibitors described in this paper is closely related to 6‐(3,5‐dimethylbenzyl)‐1‐(ethoxy methyl)‐5‐isopropyluracil (GCA‐186) an anti‐HIV‐1 drug that is highly active against both wild type and mutated HIV‐1 strains. The two methyl groups on the 6‐benzyl moiety have been shown to improve the binding stability of the drug to the NNRTI‐binding site in reverse transcriptase of drug mediated mutant HIV‐1 viruses. The methyl groups are replaced with isosteric chloro‐atoms to avoid metabolism due to the two methyl groups. However, the isosteric chloro derivatives show tenfold less activity against HIV‐1 than their corresponding methyl derivatives. The synthesis and the antiviral activities of the corresponding 1‐(allyloxy‐ and indanyloxy)methyl‐6‐(3,5‐dichlorobenzyl)‐5‐ethyluracil derivatives are also reported.
Biopsy of resectable colorectal liver metastases causes tumour dissemination and adversely affects survival after liver resection
Authors: Jones O M , Rees M , John T G , Bygrave S , Plant G
Published: July 2005

Background

Liver resection is increasingly being performed for metastatic colorectal cancer. This study assessed the need for preoperative biopsy of suspected metastases and whether biopsy has any effect on long-term survival.

Methods

Prospectively collected data on patients who underwent liver resection for colorectal metastases between 1986 and 2003 were reviewed retrospectively. The endpoints of morbidity, operative mortality and long-term survival were compared between patients who had biopsy before referral (group 1) and those who did not (group 2).

Results

Patient demographics and disease distribution were similar for 90 patients in group 1 and 508 in group 2. Seventeen patients (19 per cent) who had undergone biopsy either at the time of colorectal resection or radiologically had evidence of needle-track deposits. Operative mortality and morbidity rates in the two groups were similar. The 4-year survival rate after liver resection was 32·5 (s.e. 5·5) per cent in group 1, compared with 46·7 (2·8) per cent in group 2 (P = 0·008).

Conclusion

Needle-track deposits are common after biopsy of suspected colorectal liver metastases. Biopsy of metastases confers poorer long-term survival on patients after liver resection and cannot be justified in patients with potentially resectable disease.
Adverse effects of radiofrequency ablation of liver tumours in the Netherlands
Authors: Jansen M C , van Duijnhoven F H , van Hillegersberg R , Rijken A , van Coevorden F , van der Sijp J , Prevoo W , van Gulik T M
Published: July 2005

Background

Radiofrequency ablation (RFA) is a new treatment for liver tumours. Complications encountered after RFA in the Netherlands were evaluated in the present study.

Methods

Between June 1999 and November 2003 patients undergoing RFA of irresectable liver tumours in eight medical centres were registered prospectively.

Results

One hundred and forty-three RFA procedures were performed in 122 patients. RFA was combined with partial hepatectomy in 37 instances. Death occurred after two procedures (1·4 per cent), and was mainly due to concomitant partial hepatectomy. A total of 19 major complications occurred after ten procedures, including biliary tract damage (seven patients), liver failure (four), hepatic abscess (three), peritoneal infection (two), intrahepatic haematoma (one), hepatic artery aneurysm (one) and pulmonary embolism (one). Twenty-four minor complications were related to concomitant partial hepatectomy or laparotomy. The overall complication rate was 20·3 per cent and the rate of complications related directly to RFA was 9·8 per cent.

Conclusion

The procedure-specific complication rate was almost 10 per cent and it is recommended that RFA should be performed only by an experienced team comprising a hepatobiliary surgeon, gastroenterologist, hepatologist and interventional radiologist. Biliary stricture, hepatic vascular damage and hepatic abscesses were the most common major complications.
Treatment of loculated lactational breast abscess with a vacuum biopsy system
Authors: Varey A H R , Shere M H , Cawthorn S J
Published: July 2005

For difficult abscesses
Impaired IGF‐I signalling of hypertrophic hearts in the developmental phase of hypertension in genetically hypertensive rats
Authors: Kuo Wei‐Wen , Chu Chia‐Yih , Wu Chieh‐Hsi , Lin James A. , Liu Jer‐Yuh , Hsieh Yi‐Hsien , Ueng Kwo‐Chang , Lee Shin‐Da , Hsieh Dennis Jine‐Yuan , Hsu His‐Hsien , Chen Li‐Mien , Huang Chih‐Yang
Published: July 2005

Insulin‐like growth factor‐I (IGF‐I) signalling is reported to contribute to the modulation of blood pressure and set survival and hypertrophic responses in cardiac tissue. However, whether IGF‐I signalling normally acts in cardiac tissues of hypertensive rats is unknown. In this study, using spontaneously hypertensive rats (SHR) and stroke‐prone spontaneously hypertensive rats (SPSHR), both with early blood pressure increases, and Wistar–Kyoto (WKY) rats as controls, we measured the hypertrophic and IGF‐I signalling activity changes in rat hearts at 4, 6 and 12 weeks of age. Both SHR and SPSHR were found to have significantly increased blood pressures and ratios of heart‐ and left ventricle‐ to body weight at 12 weeks of age. However, IGF‐IR and its downstream signalling, including the protein levels of PI3K and phosphorylated Akt, known to maintain physiological cardiac hypertrophy and cardiomyocyte survival, were downregulated. The results of dot blotting showed that cardiac mRNA levels of IGF‐I in hypertensive rats were higher than those in controls starting from the age of 4 weeks. This difference suggests the increased ligand IGF‐I mRNA levels may be a compensatory response caused by the impaired IGF‐I signalling. Moreover, enhanced cardiac cytosolic cytochrome‐c, a mitochondria‐dependent apoptotic pathway component, tended to occur in both hypertensive rats, although it did not reach a significant level. These findings indicate that impaired IGF‐IR signalling occurs at early stages, and it may contribute, at least partially, to the development of hypertension and pathological cardiac hypertrophy and to cardiomyocyte apoptosis at later stages in SHR and SPSHR. Copyright © 2005 John Wiley & Sons, Ltd.
Microchemical Engineering: Components, Plant Concepts User Acceptance – Part I
Authors: Hessel V. , Löwe H.
Published: July 2005

Over the last five years, many activities have focused on the unexploited field of carrying out reactions on small scales. Due to the rapid development of new components, this paper deals with recent developments only in a compressed form. An important point is the analysis of possible plant concepts for microreactors and whether these are a sensible option. Due to the enormous difference in size between the microchannels and the fluid periphera of possible components this is not just a technical question. It touches on the microtechnology concept as a whole. The direction in which the field should be developed and which measures can be taken to influence its development are questions that are addressed here with respect to the big industrial interest in microreactors.
Higher Efficiency in Particle Flocculation by Using Combinations of Oppositely Charged Polyelectrolytes
Authors: Petzold G. , Schwarz S. , Lunkwitz K.
Published: July 2005

The separation of finely dispersed particles by flocculation is a well‐known and widely used process. The flocculation mechanism depends on the properties of polymers, especially the type of charge (negative, positive, or non‐ionic), the charge density of polyelectrolytes and the molecular weight. The discussion is focused on the advantages of a dual system (polycation/followed by polyanion) for the flocculation of washing water from the gravel industry.
Partial least squares, Beer's law and the net analyte signal: statistical modeling and analysis
Authors: Nadler Boaz , Coifman Ronald R.
Published: July 2005

Partial least squares (PLS) is one of the most common regression algorithms in chemistry, relating input–output samples (xi, yi) by a linear multivariate model. In this paper we analyze the PLS algorithm under a specific probabilistic model for the relation between x and y. Following Beer's law, we assume a linear mixture model in which each data sample (x, y) is a random realization from a joint probability distribution where x is the sum of k components multiplied by their respective characteristic responses, and each of these components is a random variable. We analyze PLS on this model under two idealized settings: one is the ideal case of noise‐free samples and the other is the case of an infinite number of noisy training samples. In the noise‐free case we prove that, as expected, the regression vector computed by PLS is, up to normalization, the net analyte signal. We prove that PLS computes this vector after at most k iterations, where k is the total number of components. In the case of an infinite training set corrupted by unstructured noise, we show that PLS computes a final regression vector which is not in general purely proportional to the net analyte signal vector, but has the important property of being optimal under a mean squared error of prediction criterion. This result can be viewed as an asymptotic optimality of PLS in the limit of a very large but finite training set. Copyright © 2005 John Wiley & Sons, Ltd.
Influence of HMPA on the Stereochemical Outcome of the Addition of a Racemic Allenylzinc onto Enantiopure N‐tert‐Butanesulfinimines: Stereoselective Access to Enantiopure cis‐Ethynylaziridines
Authors: Ferreira Franck , Audouin Max , Chemla Fabrice
Published: July 2005

In the presence of 60 equivalents of HMPA, the condensation of the racemic allenylzinc derived from 1‐chloro‐3‐trimethylsilylpropyne onto enantiopure non‐α‐branched N‐tert‐butanesulfinimines was proven to give access to the corresponding cis‐ethynylaziridines as the major products. The good cis selectivity observed presumably resulted from a high kinetic resolution with the allenylzinc being partially configurationally labile with respect to the time scale defined by the rate of the reaction. Both single crystal X‐ray analysis and semiempirical calculations conducted at the MM2 and AM1 levels of theory proved that the reaction certainly occurred through a preferred synclinal transition state in a supra‐ or antarafacial SE2′ process. In all cases, chromatographic purification over silica gel allowed the cis‐ethynyl‐N‐tert‐butanesulfinylaziridines to be obtained as diastereo‐ and enantiomerically pure compounds (dr >98:2 and ee >99 %).
Role for the α7β1 integrin in vascular development and integrity
Authors: Flintoff‐Dye Nichole L. , Welser Jennifer , Rooney Jachinta , Scowen Paul , Tamowski Susan , Hatton William , Burkin Dean J.
Published: July 2005

The α7β1 integrin is a laminin receptor that has been implicated in muscle disease and the development of neuromuscular and myotendinous junctions. Studies have shown the α7β1 integrin is also expressed in nonskeletal muscle tissues. To identify the expression pattern of the α7 integrin in these tissues during embryonic development, α7 integrin chain knockout mice were generated by a LacZ knockin strategy. In these mice, expression from the α7 promoter is reported by β‐galactosidase. From embryonic day (ED) 11.5 to ED14.5, β‐galactosidase was detected in the developing central and peripheral nervous systems and vasculature. The loss of the α7 integrin gene resulted in partial embryonic lethality. Several α7 null embryos were identified with cerebrovascular hemorrhages and showed reduced vascular smooth muscle cells and cerebral vascularization. The α7 null mice that survived to birth exhibited vascular smooth muscle defects, including hyperplasia and hypertrophy. In addition, altered expression of α5 and α6B integrin chains was detected in the cerebral arteries of α7 null mice, which may contribute to the vascular phenotype. Our results demonstrate for the first time that the α7β1 integrin is important for the recruitment or survival of cerebral vascular smooth muscle cells and that this integrin plays an important role in vascular development and integrity. Developmental Dynamics 234:11–21, 2005. © 2005 Wiley‐Liss, Inc.
Synthesis and Characterisation of Monodisperse Zirconia Particles
Authors: Widoniak Johanna , Eiden‐Assmann Stefanie , Maret Georg
Published: July 2005

Monodisperse spherical ZrO2 particles were prepared by controlled hydrolysis of zirconium tetraalkoxide in alcoholic solution. Ageing the reaction solution at 60 °C for 4 h yields particles with sizes in the range between 200 and 2000 nm. The influence of various ions and surfactants on the final product was investigated. Stable suspensions of coated, monodisperse, zirconia particles were prepared by hydrolysis and subsequent polymerisation of tetraethoxysilane in an alkaline ethanol solution. Thermal analysis revealed that the weight loss of bound water occurred below 400 °C and is about 35 %. The phase transition from amorphous zirconia to the tetragonal phase proceeded at approximately 450 °C, the transition to the monoclinic phase began at about 600 °C and was completed at about 800 °C. The crystallinity of the powders was investigated by X‐ray diffraction. Electrophoretic measurements were carried out to determine the charges on the particle surface. Elementary analyses were used for further investigations. On the basis of the results obtained, the mechanism of particle formation was discussed. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Synthesis, Crystal Structure, and Magnetic Properties of a Three‐Dimensional Hydroxide Sulfate: Mn5(OH)8SO4
Authors: Fan Yong , Hua Li Guang , Yang Lei , Ming Zhang Zhi , Chen Yan , You Song Tian , Hua Feng Shou
Published: July 2005

A 3D hydroxysulfate, Mn5(OH)8SO4, formed from a mild hydrothermal reaction has been reported. The compound crystallizes in the triclinic system P$\tilde {1}$ with cell parameters a = 7.5501(5) Å, b = 8.5558(6) Å, c = 8.6059(5) Å, α = 98.122(4)°, β = 102.370(4)°, γ = 99.646(4)°, V = 526.19(6) Å3 and Z = 2. The crystal structure consists of a 3D framework with channels along the c‐axis. In this structure, the manganese atoms in the distorted pentahedra and octahedra are interconnected by OH groups to form layers along the bc plane. These layers are further connected with MnO5 distorted pentahedra, MnO6 octahedra and [SO4]2– tetrahedra, resulting in a complicated network. The temperature dependence of the magnetic susceptibility shows a weak antiferromagnetic interaction in the compound. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Synthesis and Physico‐Chemical Properties of Novel Biocompatible AlkylD‐Mannopyranosiduronate Surfactants Derived from Alginate
Authors: Roussel Myriam , Benvegnu Thierry , Lognoné Vincent , Le Deit Hervé , Soutrel Isabelle , Laurent Isabelle , Plusquellec Daniel
Published: July 2005

The present article describes the preparation and the physico‐chemical properties of novel biocompatible surfactants derived from alginate for applications in detergents and cosmetics. Controlled acid hydrolysis of commercially available alginate fromLaminaria digitatagives saturated oligo‐mannuronates on a multigram scale. Subsequent one‐pot acid glycosidic bond hydrolysis, esterification and stereocontrolled Fischer glycosylation in butanol with the related oligouronates efficiently providesn‐butyl (n‐butyl α‐D‐mannopyranosiduronate) (3). Double‐tailed amphiphiles were next obtained from this key intermediate3by transesterification/transglycosylation processes in fatty alcohols. Aqueous basic and acid treatments furnished anionic or neutral single‐tailed surfactants. These original alginate‐derived amphiphiles exhibit attractive surface‐tension and foaming properties. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Development of New Amino(oxo)piperidinecarboxylate Scaffolds and Their Evaluation as ‐Turn Mimics
Authors: Verbist Bie M. P. , De Borggraeve Wim M. , Toppet Suzanne , Compernolle Frans , Hoornaert Georges J.
Published: July 2005

In this paper a synthetic approach for functionalised bicyclic Amino(oxo)piperidinecarboxylate (APC) systems is presented. These systems can potentially be applied as cis‐peptide bond containing β‐turn mimics. The scope and limitations of the synthetic method are discussed and the turn‐inducing properties of a model compound are evaluated by means of molecular modelling and NMR analysis. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Dehydrogenation of Amines to Nitriles in Aqueous Micelles
Authors: Biondini Daniele , Brinchi Lucia , Germani Raimondo , Goracci Laura , Savelli Gianfranco
Published: July 2005

An aqueous reaction medium, based on a surfactant solution of dimethyldodecylamine N‐oxide (DDAO) has been developed for the oxidative dehydrogenation of primary amines using NiSO4 as catalyst and K2S2O8 as oxidant. This reaction medium enhances the rate of the reaction relative to other media previously reported in the literature, which are also toxic. The reactions of various aliphatic and cyclic amines have been investigated and gave nitriles with yields of >90 % in mild conditions. The aqueous surfactant solution and reagents were recycled for future use. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
An Efficient [2+3] Cycloaddition Approach to the Synthesis of Pyridyl‐Appended Fullerene Ligands
Authors: Troshin Pavel A. , Peregudov Alexander S. , Mühlbacher David , Lyubovskaya Rimma N.
Published: July 2005

We have used 2‐, 3‐, and 4‐picolylamines and their various N‐substituted derivatives as substrates to generate azomethine ylides for [2+3] cycloaddition to [60]fullerene. A considerable difference in the reactivity of isomeric picolylamines was observed; however, even less reactive 3‐picolylamines afford high yields of products under acid or base catalysis. This method provides easy access to a large family of valuable ligands (pyridyl‐substituted pyrrolidinofullerenes) that can be used in the design of transition‐metal complexes and non‐covalently bonded dyads with metalloporphyrins. Unusually high yields of products and convenience of synthetic procedures (2–10 min heating the reagents at reflux in 1,2‐dichlorobenzene in air in most cases) as well as a wide synthetic potential make this reaction a good alternative to the commonly used Prato method. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Reactivity of 3‐Styrylchromones as Dienes in Diels–Alder Reactions under Microwave Irradiation: A New Synthesis of Xanthones
Authors: Pinto Diana C. G. A. , Silva Artur M. S. , Brito Cristela M. , Sandulache Angela , Carrillo José R. , Prieto Pilar , Díaz‐Ortiz Angel , de la Hoz Antonio , Cavaleiro José A. S.
Published: July 2005

Microwave irradiation under solvent‐free conditions induced 3‐styrylchromones to undergo Diels–Alder cycloaddition reactions with N‐methyl‐ and N‐phenylmaleimide as well as with other dienophiles. In some of these reactions the cycloadducts underwent in situ oxidation to give xanthones, whereas in other cases it was necessary to add DDQ as an oxidant. The reactions of 3‐styrylchromones with N‐methyl‐ and N‐phenylmaleimide gave the cycloadducts 4‐aryl‐1,3‐dioxo‐3a,4,11a,11b‐tetrahydropyrrolo[3,4‐c]xanthones, which were oxidised to 4‐aryl‐1,3‐dioxopyrrolo[3,4‐c]xanthones with DDQ. The reactions of 3‐styrylchromones with 2‐(2‐nitrovinyl)thiophene gave 2‐aryl‐3‐(2‐thienyl)xanthones directly through a Diels–Alder reaction followed by HNO2 elimination and oxidation. The cycloaddition reactions of 3‐styrylchromones described herein are stereoselective. The reactions of (Z)‐ and (E)‐3‐styrylchromones with N‐methylmaleimide gave, respectively, the endo and exo cycloadducts, while reactions of (Z)‐3‐styrylchromones with the less reactive dienophile N‐phenylmaleimide gave a mixture of compounds. This mixture contained the expected endo cycloadduct and another compound that was identified as the exo adduct of the reaction between the (E)‐3‐styrylchromone — obtained in situ from the isomerisation of its (Z) isomer — and N‐phenylmaleimide. The regio‐ and stereoselectivity of these cycloaddition reactions have been studied by ab initio calculations and can be understood in terms of a thermodynamically controlled reaction. Theoretical calculations are in complete agreement with the experimental results. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Selenium‐Containing Heterocycles From Isoselenocyanates: Synthesis of1,3‐Selenazolidine and Perhydro‐1,3‐selenazine Derivatives
Authors: Sommen Geoffroy L. , Linden Anthony , Heimgartner Heinz
Published: July 2005

Treatment of ω‐halo alkylamines 9 and 10 with aryl and alkyl isoselenocyanates 6a–g in the presence of triethylamine in dichloromethane gave the corresponding 1,3‐selenazolidines 11a–g and perhydro‐1,3‐selenazines 12a–g, respectively, in good to excellent yields. Chemical and spectroscopic evidence for the structures of all new compounds are presented, and in selected examples the molecular structures have been established by X‐ray crystallography. The analogous reactions with isothiocyanates have been used for the preparation of 1,3‐thiazolidines and perhydro‐1,3‐thiazines. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Cobalt(I)‐Mediated Intramolecular [2+2+2] Cocyclizations of (Methylenecyclopropyl)diynes as an Easy Access to Cyclopropanated Oligocycles
Authors: Schelper Michael , Buisine Olivier , Kozhushkov Sergei , Aubert Corinne , de Meijere Armin , Malacria Max
Published: July 2005

Enediynes with methylenecyclopropane moieties attached either through the three‐membered ring or the double bond smoothly underwent cobalt‐mediated [2+2+2] cocyclizations to give cyclopropane‐fused and spirocyclopropanated cobalt‐complexed tricyclo[7.3.0.02,6]dodeca‐1,6‐dienes (1,2,3,3a,4,6,7,8‐octahydro‐as‐indacenes) under relatively mild conditions in yields ranging from 31 to 94 % (6 examples). Electron‐withdrawing substituents at the acetylenic terminus of the precursor are essential for a successful oligocyclization. While diphenyloxyphosphinyl‐substituted enediynes provided tricyclo[7.3.0.02,6]dodeca‐1,6‐diene complexes as mixtures of two diastereomers in high yields, the analogous methoxycarbonyl‐substituted precursors gave only one diastereomer. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Synthesis of a Bisphthalocyanine and Its Nonlinear Optical Properties
Authors: Calvete Mario J. F. , Dini Danilo , Flom Steven R. , Hanack Michael , Pong Richard G. S. , Shirk James S.
Published: July 2005

The synthesis and the nonlinear optical properties of an axially substituted binuclear InCl/InCl phthalocyanine 1 with an unsymmetrical substitution pattern are described. The preparation of this new type of binuclear phthalocyanine has been carried out through a multi‐step synthetic strategy, which was specially developed for binuclear phthalocyanines. The study has been carried out with the aim of analyzing which variations of the electronic properties accompany the unsymmetrical extension of the π‐electron system of a binuclear Pc when compared to a mononuclear Pc (the complex tBu4PcInCl is here taken for comparison). The nonlinear optical properties of InCl/InCl phthalocyanine 1 in toluene were studied with the Z‐scan technique in both open‐ and closed‐aperture configurations at 532 nm with nanosecond laser pulses. The binuclear complex displayed a positive nonlinear absorption coefficient. It is found that the linear optical properties were little changed but the optical limiting effectiveness of the binuclear fused phthalocyanine 1 is lower relative to tBu4PcInCl. Explanations for such differences are given. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Regiochemical Control by Remote Substituents – A Selective Synthesis of Angularly Fused Ring Systems
Authors: Kraus George A. , Zhang Ning , Wei Jing Qiang , Jensen Jan H.
Published: July 2005

Diels–Alder reactions of quinones 4, 7, and 15 exhibit remarkable regioselectivity. In contrast, the Diels–Alder reaction of quinone 12 showed no regioselectivity, indicating that the regioselectivities are due to electronic interactions. The selectivity is nicely explained using molecular electrostatic potentials. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Associations between small intestine cancer and other primary cancers: An international population‐based study
Authors: Scélo Ghislaine , Boffetta Paolo , Hemminki Kari , Pukkala Eero , Olsen Jorgen H. , Andersen Aage , Tracey Elizabeth , Brewster David H. , McBride Mary L. , Kliewer Erich V. , Tonita Jon M. , Pompe‐Kirn Vera , Chia Kee‐Seng , Jonasson Jon G. , Martos Carmen , Colin Didier , Brennan Paul
Published: July 2005

Cancer of the small intestine is a rare neoplasm, and its etiology remains poorly understood. Analysis of other primary cancers in individuals with small intestine cancer may help elucidate the causes of this neoplasm and the underlying mechanisms. We included 10,946 cases of first primary small intestine cancer from 13 cancer registries in a pooled analysis. The observed numbers of 44 types of second primary cancer were compared to the expected numbers derived from the age‐, gender‐ and calendar period‐specific cancer incidence rates in each registry. We also calculated the standardized incidence ratios (SIR) for small intestine cancer as a second primary after other cancers. There was a 68% overall increase in the risk of a new primary cancer after small intestine carcinoma (SIR = 1.68, 95% confidence interval [CI] = 1.47–1.71), that remained constant over time. The overall SIR was 1.18 (95% CI = 1.05–1.32) after carcinoid, 1.29 (1.01–1.63) after sarcoma, and 1.27 (0.78–1.94) after lymphoma. Significant (p < 0.05) increases were observed for cancers of the oropharynx, colon, rectum, ampulla of Vater, pancreas, corpus uteri, ovary, prostate, kidney, thyroid gland, skin and soft tissue sarcomas. Small intestine cancer as a second primary was increased significantly after all these cancers, except after oropharyngeal and kidney cancers. Although some of the excess may be attributable to overdiagnosis, it is plausible that most additional cases of second primary cancers were clinically relevant and were due to common genetic (e.g., defects in mismatch or other DNA repair pathways) and environmental (e.g., dietary) factors. © 2005 Wiley‐Liss, Inc.