bluuebunny/crossref_metadata_2025 huggingface dataset:
Dynamics of subcellular organelles, growth hormone, Rab3B, SNAP‐25, and syntaxin in rat pituitary cells caused by growth hormone releasing hormone and somatostatin
Authors: Matsuno Akira , Itoh Johbu , Takekoshi Susumu , Itoh Yoshiko , Ohsugi Yoshitaka , Katayama Haruko , Nagashima Tadashi , Osamura R. Yoshiyuki
Published: September 2003

Rab3B is involved in the exocytosis of synaptic vesicles and secretory granules in the central nervous system and the anterior pituitary cells. The aim of this study was to elucidate both the role of rab3B in GH secretion and the mutual relationship of rab3B and SNARE proteins. Adult male rats were injected intravenously with 10 μg of growth hormone releasing hormone (GHRH) or 10 μg of somatostatin (SRIF). Untreated rats were used as controls, and their pituitary glands were sectioned for histochemical examination. Rab3B is localized on the limiting membrane of the secretory granules and the cytosol. Confocal laser scanning microscopic observation of immunohistochemical double staining of rab3B and GH revealed that immunoreactivity of rab3B increased in GHRH‐treated rats and decreased in SRIF‐treated rats. Confocal laser scanning microscopic observation of immunohistochemical double staining of SNAP‐25, syntaxin, and rab3B revealed the co‐localization of rab3B and these SNARE proteins in GHRH‐treated rats, and their dissociation in SRIF‐treated rats. These results suggest that rab3B plays a principal role in GH secretion in the anterior pituitary cells and that SNAP‐25 and syntaxin act as co‐workers with rab3B in the functional regulation of GH secretion. Microsc. Res. Tech. 62:232–239, 2003. © 2003 Wiley‐Liss, Inc.
Lymph drainage in the human dental pulp
Authors: Oehmke Matthias J. , Knolle Erich , Oehmke Hans‐Joachim
Published: September 2003

We investigated which structural components are responsible for maintaining interstitial fluid equilibrium in the pulpal tissue, for which the existence of an effective lymph drainage is postulated. There have been only a small number of investigations on pulpal lymph tissue. Therefore, we decided to perform a detailed structural analysis. Twenty vital, healthy teeth that had to be extracted for orthodontic reasons were immersed in Patent Blue for 10 to 15 minutes after opening the pulpal cavity. They were then extracted and the dental pulps were opened by cleavage of the surrounding hard tooth structure. Subsequently, the specimens were prepared for light and electron microscopic investigation. A clear blue ring of stain was detected by light microscopy in Weil's zone in the coronal region of the pulp, the cell‐rarefied layer surrounded by the odontoblasts. No dye deposition was observed in the apical part. However, using transmission electron microscopy, capillary structures with typical morphological characteristics of lymphatic vessels were found apically. The coronal part of the pulp did not reveal any such vascular structures. It may be concluded from these findings that the lymph in the coronal region is collected in interstitial tissue clefts and drained towards the apex, whence it is further transported via lymph capillaries. Microsc. Res. Tech. 62:187–191, 2003. © 2003 Wiley‐Liss, Inc.
Intranucleolar localization of DNA topoisomerase IIα is a distinctive feature of necrotic, but not of apoptotic, Jurkat T‐cells
Authors: Falcieri Elisabetta , Burattini Sabrina , Bortul Roberta , Luchetti Francesca , Tabellini Giovanna , Tazzari Pier Luigi , Cappellini Alessandra , Cocco Lucio , Martelli Alberto M.
Published: September 2003

Two distinct types of cell death have been described: apoptosis and necrosis. However, it is becoming increasingly clear that the differences between these two types are far less numerous than initially thought. Morphological analyses might provide important information to distinguish apoptotic from necrotic samples. We recently reported that in necrotic, but not apoptotic, HL‐60 human myeloid leukaemia cells, the nuclear protein topoisomerase IIα concentrated in nucleoli. In order to ascertain whether or not this phenomenon was restricted to a peculiar cell type or could be detected also in cells of lymphoid lineage, we performed an investigation aimed at defining the localization of topoisomerase IIα in apoptotic and necrotic Jurkat human T lymphoblastoid cells. Immunofluorescence staining demonstrated that topoisomerase IIα was excluded from the condensed chromatin of apoptotic cells, whereas in necrotic cells it was localized in discrete nuclear dots. Immuno‐electron microscopy analysis showed that topoisomerase IIα was undetectable in nucleoli of normal and apoptotic cells, whereas it was present in the nucleolus of necrotic cells irrespectively of the type of inducer used (ethanol, H2O2, HgCl2). Taken together, our findings identify topoisomerase IIα as a potential morphological marker useful to discriminate between apoptotic and necrotic cells. Microsc. Res. Tech. 62:192–200, 2003. © 2003 Wiley‐Liss, Inc.
Morphology, ultrastructure, and implied function of ciliated sensory structures on the developmental stages of Merizocotyle icopae (Monogenea: Monocotylidae)
Authors: Cribb Bronwen , Chisholm Leslie , Gould Robert , Whittington Ian
Published: September 2003

Experimental infections were used to track the fate of the dorsal sensilla of Merizocotyle icopae (Monogenea: Monocotylidae) from nasal tissue of the shovelnose ray, Rhinobatos typus (Rhinobatidae). Scanning and transmission electron microscopy revealed that 3 types of uniciliate dorsal sensilla exist at different times in the development of the monogenean. Type 1 sensilla have little or no invagination where the cilium exits the distal end of the dendrite and possess a ring of epidermis surrounding the cilium distal to the invagination. Type 2 sensilla have a deep invagination where the cilium exits the dendrite. Type 3 sensilla can be distinguished from the other types by the shape of the dendrite. The larvae have predominantly Type 1 dorsal sensilla, most of which are lost approximately 24 h after infection and a few Type 2 sensilla, which are retained. Additional Type 2 sensilla (termed Adult Type 2 sensilla), which are slightly different morphologically from the Type 2 sensilla of the larvae, form in later stages of development. Numerous Type 3 sensilla are unique to the dorsal surface of adults. Loss of all Type 1 sensilla upon attachment to the host, R. typus, suggests that these may be chemo‐ or mechanoreceptors responsible for host location by the swimming infective larvae. Type 2 sensilla appear to be important in the larvae, juveniles, and adults whereas the modality mediated by Type 3 is specific to adults. Microsc. Res. Tech. 62:267–276, 2003. © 2003 Wiley‐Liss, Inc.
Ultrastructure and three‐dimensional study of the lymphatic stomata in the costal pleura of the rabbit
Authors: Li Yan‐Yuan , Li Ji‐Cheng
Published: September 2003

The aim of this report was to investigate the ultrastructure and three‐dimensional organization of the pleural lymphatic stomata in the adult rabbit costal pleura by electron microscopy. A computer image processing system attached to the scanning electron microscopy was used to get statistical evaluation of the dimensions of pleural lymphatic stomata. Mesothelial cells were digested by 2 mol/L NaOH solution in order to expose the submesothelial connective tissue with macula cribriformis. Two kinds of mesothelial cells were observed on the costal pleura: the flattened cells and the cuboidal ones. Both had microvilli on their surface. Pleural lymphatic stomata were located only in the regions of cuboidal mesothelial cells. The average area of a stoma was 7.20 ± 3.69 μm2 and their average density 121 ± 72/mm2. Pleural cavity is connected with the lympo‐vascular system by lymphatic stomata and the interstitial layer with a dense network of lamina cribriformis. The macula cribriformis (7–60 μm in diameter) were found in subpleural connective tissue below the cuboidal mesothelial cells. Consequently on cross‐section, the pathway represents a channel consisting of the stoma, the connective tissue space, and the gap between endothelial cells of the lymphatics. Closed lymphatic stomata and the milky spots composed of macrophages could be observed on the costal pleura. Our results suggest that the pleural cavity is connected with the lymphatic capillaries through the lymphatic stomata and the subpleural channel. This is the only “highway” from the pleural cavity to the vessels. This pathway may be importantly involved in the material exchange and the immunity of the pleura cavity. Microsc. Res. Tech. 62:240–246, 2003. © 2003 Wiley‐Liss, Inc.
A simple, low‐cost device for processing and embedding tissues at sub‐zero temperatures
Authors: Shoemaker Wayne , Hayes Craig , Phillips Thomas E.
Published: September 2003

A simple apparatus to maintain tissues samples at sub‐zero temperatures during dehydration, infiltration, and polymerization is described. The device uses a conventional siphon‐type carbon dioxide gas cylinder to maintain an aluminum block at temperatures as low as −35°C for over 15 hours/cylinder. Microsc. Res. Tech. 62:262–266, 2003. © 2003 Wiley‐Liss, Inc.
Distribution of muscimol, QNB, and 5HT binding in the vertebrate diencephalon: A comparative study of eight mammals and three non‐mammals
Authors: Glendenning K.K.
Published: September 2003

The distribution of muscimol, quinuclidinyl benzilate (QNB), and serotonin (5HT)‐bound receptors in the diencephalon was examined by conventional receptor‐binding methods in 11 species of amniotes including 2 reptiles, 1 bird, and 8 mammals, selected mostly on the basis of their differing last common ancestor with Anthropoids. We found that receptor binding can help define major subdivisions of the forebrain. The results show that in each of these species, the distribution of muscimol and QNB binding across the four major subdivisions of the diencephalon was consistent; densest in the dorsal thalamus, with hypothalamus and then either ventral thalamus or epithalamus with successively lesser amounts. However, the binding of serotonin (5HT) was most prevalent in the hypothalamus with equivalent amounts in the other diencephalic subdivisions. Myelin‐ and cell‐stained materials showed that the pattern of high‐density binding probably is not the secondary result of non‐neurochemical factors such as differences in cell or neuropil density or in total available membrane. Perhaps more importantly, the receptor distributions suggest functional roles for major subdivisions across taxa. Results show that GABA‐A and muscaranic Ach receptors are common in the dorsal diencephalon across vertebrate species and, therefore, are probably responsible for the gating of information to the cortex. Results show that serotonin is predominant in the hypothalamus. The lack of it in the dorsal thalamus indicates that it is probably not responsible for gating of information to the cortex. Results also show that in nonmammals the amount of GABA‐A and muscaranic Ach differs from that found in mammals. For muscaranic Ach, the labeling in marsupials differs from that in placentals. Primates differ from other species (nonmammals and mammals combined) in the amount of 5HT found in the ventral diencephalon and the hypothalamus. Microsc. Res. Tech. 62:247–261, 2003. © 2003 Wiley‐Liss, Inc.
Red blood cells labelling with 99mTc‐d,l‐HMPAO: an alternative method for specific cases
Authors: Pérez F.J. , Matilla A. , Tercero J.M. , Martínez F. , Becerra D.
Published: September 2003

The effectiveness of the classic methods for red blood cells (RBCs) labelling with 99mTc has been demonstrated in nuclear medicine. However, nuclear physicians have found, in certain circumstances, this diagnostic technique fails and poor quality images are obtained. In this work we report on an alternative method that is of useful in these occasions, for in vitro labelling RBCs with 99mTc‐d,l‐HMPAO complex. The study shows a high and reproducible labelling efficiency (94.14±0.38), using low amount of tin. The RBCs were isolated from plasma and other interfering blood cells before adding 99mTc‐d,l‐HMPAO. The tracer was retained and the elution rate from RBCs was low (less than 6% after 120 min). The preclinical results indicate that this new method could be a good alternative to the standard classic methods for specific cases. Copyright © 2003 John Wiley & Sons, Ltd.
Syntheses of novel N‐([18F]fluoroalkyl)‐N‐nitroso‐4‐methyl‐benzenesulfonamides and decomposition studies of corresponding 19F‐ and bromo‐analogues: potential new compounds for the 18F‐labelling of radiopharmaceuticals
Authors: Schirrmacher Ralf , Mathiasch Bernd , Schirrmacher Esther , Radnic Dragana , Rösch Frank
Published: September 2003

N‐([18F]fluoroalkyl)‐N‐nitroso‐4‐methyl‐benzensulfonamides [n‐alkyl = (−CH2)[18,19F]F, n=2–4)] were synthesized in radiochemical yields ranging from 75–90% to provide new secondary labelling precursors for the syntheses of 18F‐labelled compounds. Preliminary decomposition studies utilizing the corresponding non‐radioactive 19F‐compounds as well as the bromo containing analogous compounds were performed to evaluate their stability regarding temperature and basicity of the labelling medium. Furthermore, initial difficulties in labelling these compounds led to the development of a modified labelling procedure applying nearly solvent‐free conditions. Extensive decomposition experiments of the new fluoro‐ as well as the bromo‐compounds were conducted under various conditions in order to get experimental data about their stability and reactivity. As a result, different trends for the stability of the bromo as well as the fluoro compounds could be observed. Copyright © 2003 John Wiley & Sons, Ltd.
2‐, 3‐ and 4‐[18F]Fluoropyridine by no‐carrier‐added nucleophilic aromatic substitution with K[18F]F‐K222 – a comparative study
Authors: Karramkam M. , Hinnen F. , Vaufrey F. , Dollé F.
Published: September 2003

Compared to homoaromatic and aliphatic nucleophilic radiofluorinations, only few references can be found in the literature describing nucleophilic substitutions with [18F]fluoride ion of heteroaromatic compounds such as pyridines and only reactions involving fluorination processes at the ortho‐position (2‐position) have been more intensively studied. In the present paper, the scope of the nucleophilic aromatic fluorinations at the meta‐ and para‐position of the pyridine ring with no‐carrier‐added [18F]fluoride ion as its activated K[18F]F‐K222 complex has been evaluated and compared to the nucleophilic aromatic fluorinations at the ortho‐position in this pyridine series. The syntheses of 3‐ and 4‐[18F]fluoropyridines were chosen as model reactions and compared to the radiosynthesis of 2‐[18F]fluoropyridine. The parameters studied include the influence of the position of the leaving group at the pyridine ring, as well as the quantity of the precursor used, the type of activation (conventional heating, microwave irradiation), the solvent, the temperature and the reaction time. Using the corresponding nitro precursor, high yields were obtained at the 2‐position (94% yield) using microwaves (100 W) for 2 min in DMSO. Good yields (up to 72%) were observed at the 4‐position using the same conditions while practically no reaction was observed at the 3‐position. About 60% yield was also obtained at both the 2‐ and 4‐position using the corresponding nitro precursor at 145°C for 10 min in DMSO. Copyright © 2003 John Wiley & Sons, Ltd.
Supercritical fluids in medical radioisotope processing and chemistry, Part I: technology, instrumentation and methodology
Authors: Ferrieri Richard A.
Published: September 2003

Although the last two decades has seen a keen interest in using supercritical fluids as media for material processing and chemical reactions owing to their unique physical properties, this technology has been underutilized in medical radioisotope processing and chemistry. The successful application of this technology necessitates not only having a sound knowledge of the physico‐chemical properties and phenomena occurring within such critical states of matter, but also a clear idea of the tools needed and means for applying them. These topics will be presented under the cover of two parts. Part I will address topics on the general background of supercritical fluid technology, equipment needed, whether for chemistry or separation, and basic techniques to access critical states of matter. Part II will follow in a subsequent volume and is meant to provide a description of applications with cited examples and potential areas for development. The hope is that sufficient interest is stimulated so as to encourage radiochemists to look to alternative technologies of this nature to solve their daily laboratory challenges. Copyright © 2003 John Wiley & Sons, Ltd.
Supercritical fluids in medical radioisotope processing and chemistry, Part II: Applications – real and demonstrated
Authors: Ferrieri Richard A.
Published: September 2003

In Part I of this review series, an overview was presented on what the basic properties of supercritical fluids are and how they can, and are being used in many of today's industries as solvents for extraction, chromatography and reaction. A good part of this overview detailed the kinds of equipment needed, and techniques on how to use them for optimal performance. Part II of this series will delve into specific applications of supercritical fluid technology as it relates to aspects of medical isotope processing. The reader will note that very few applications of this technology to Nuclear Medicine have been published. Many potential applications cited within the context of this review derive from preliminary studies carried out in the author's laboratory. These examples are presented to spark interest in future developments of this nature. Copyright © 2003 John Wiley & Sons, Ltd.
Synthesis of two non‐peptidyl GnRH receptor antagonists via [14C]carbonylation
Authors: Elmore Charles S. , Dean Dennis C. , DeVita Robert J. , Melillo David G.
Published: September 2003

In support of a program to develop a new gonadotropin releasing hormone (GnRH) receptor antagonist, two 14C labelled candidate tracers, 14C‐1 and 14C‐2, were synthesized for utilization in metabolism studies. A slight modification of the Medicinal Chemistry route for the synthesis of the antagonists provided iodide 4. Palladium (0) catalyzed [14C]carbonylation of 4 proceeded in good chemical yield to afford acid 14C‐3 which served as a common precursor to 14C‐1 and 14C‐2. Copyright © 2003 John Wiley & Sons, Ltd.
The l2/a4 theorem of waveguide CARS enhancement revised for hollow microstructure fibers
Authors: Zheltikov A. M.
Published: September 2003

The ways of optimizing waveguide coherent anti‐Stokes Raman scattering (CARS) in hollow microstructure fibers are considered. The theorem predicting an l2/a4 enhancement for the waveguide CARS process in a hollow fiber with an inner radius a and length l is revised to include new solutions offered by microstructure fibers. The maximum CARS enhancement in a hollow microstructure fiber is shown to scale as λ2/α2a4 with radiation wavelength λ, radiation losses α and inner fiber radius a, allowing CARS efficiency to be substantially improved with respect to standard, solid‐cladding hollow fibers. Copyright © 2003 John Wiley & Sons, Ltd.
Raman spectra of molecular crystals at high pressures: VIII—Boron tribromide
Authors: Anderson A. , Lettress L. M.
Published: September 2003

Raman spectra of liquid and solid boron tribromide, BBr3, at ambient temperature and at pressures up to 10 GPa are reported. The freezing pressure was determined as 0.38 ± 0.05 GPa. Three fundamental peaks, assigned as librational, bending and stretching modes, were tracked as a function of pressure, and their wavenumbers were fitted to quadratic functions and approached asymptotic values at the highest pressures. The spectra evolved smoothly and there was no evidence of discontinuities associated with structural phase transitions or of major molecular distortions in this pressure range. All modes showed increases in wavenumber with pressure, and that of the lattice mode was appreciable, corresponding to a more than four‐fold increase in intermolecular bonding strength at 10 GPa. At high pressures, there was a minor but irreversible colour change of the sample, probably indicative of molecular dissociation and the release of bromine. The results were compared with corresponding data on BI3 and with those obtained from samples at low temperatures. Copyright © 2003 John Wiley & Sons, Ltd.
Hollow‐core photonic‐crystal fibers optimized for four‐wave mixing and coherent anti‐Stokes Raman scattering
Authors: Konorov S. O. , Fedotov A. B. , Sidorov‐Biryukov D. A. , Beloglazov V. I. , Skibina N. B. , Shcherbakov A. V. , Zheltikov A. M.
Published: September 2003

Hollow‐core photonic‐crystal fibers optimized for four‐wave mixing (FWM) and coherent anti‐Stokes Raman scattering (CARS) spectroscopy were designed and fabricated. These fibers provide maximum transmission for a two‐color pump and the FWM signal, allowing FWM to be enhanced by a factor of ∼800 compared with the tight‐focusing regime. A reliably detectable FWM signal was generated under these conditions with micro‐ and even submicrojoule picosecond pump pulses, i.e. at the level of pump energies unprecedentedly low for non‐resonant FWM in the gas phase. The FWM efficiency is shown to depend on the relative orientation of polarization vectors of input pump pulses, offering the extension of FWM and CARS polarization techniques to air‐guided modes in photonic‐crystal fibers. Copyright © 2003 John Wiley & Sons, Ltd.
Raman, infrared and 13C NMR studies on betaine–sulfamic acid (2:1) crystal and its hydrogen bonds
Authors: Ilczyszyn Maria M. , Ilczyszyn Marek
Published: September 2003

The betaine–sulfamic acid (2:1) crystal complex has been investigated by infrared and Raman experiments in polarized light and by cross‐polarization magic angle spinning 13C NMR. Very short and symmetric hydrogen bonds formed by acidic protons and betaine carboxylate groups (—COO—H—OOC—)+ are characterized by the Raman tensor α′(R) available from Raman symmetric stretching vibrations of the carboxylic groups and by the 13C shielding tensor σ of these groups. The principal components of the both tensors were found as to be strongly related: σii = 93.12 + 0.125α′(R)ii. The sulfamate NH2 group reorientation was characterized by Raman bandshape analysis at different temperatures. The energy of very weak O· · ·H—N—H· · ·O hydrogen bonds between the sulfamate and betaine moieties was characterized in this way. Copyright © 2003 John Wiley & Sons, Ltd.
Raman spectroscopy, surface‐enhanced Raman spectroscopy and density functional theory studies of 2‐formylfuran
Authors: Iliescu T. , Bolboaca M. , Pacurariu R. , Maniu D. , Kiefer W.
Published: September 2003

The Raman spectrum of 2‐formylfuran in the liquid phase shows pairs of bands whose temperature and solvent dependence behavior can be interpreted in terms of cis–trans conformational equilibrium. Density functional theory (DFT) calculations performed at the BPW91/6–311+G* and B3LYP/6–311+G* theoretical levels show that the trans‐isomer is more stable than the cis‐isomer by 2.81 and 3.12 kJ mol−1, respectively. The theoretical ΔH values obtained at these theoretical levels [2.99 kJ mol−1 (BPW91) and 3.2 kJ mol−1 (B3LYP)] are very close to the experimental value ΔH = 2.52 kJ mol−1 determined from the plots of logarithmic relative intensities of the band pairs 1673/1692, 1477/1465 and 1396/1371 cm−1 of these isomers against reciprocal temperature. The surface‐enhanced Raman spectrum of 2‐formylfuran in silver colloid suggests the chemisorption of this molecular species on the silver surface both through the ring oxygen and the oxygen atom of the substituent group, the cis‐form being preferred in the adsorption state. The adsorbed molecules are oriented perpendicular or least tilted with respect to the silver surface. Copyright © 2003 John Wiley & Sons, Ltd.
Vibrational spectroscopic studies, conformations and ab initio calculations of 1,1,1‐trifluoropropyltrifluorosilane
Authors: Gruodis A. , Aleksa V. , Powell D. L. , Klaeboe P. , Nielsen C. J. , Guirgis G. A. , Durig J. R.
Published: September 2003

Infrared spectra of 1,1,1‐trifluoropropyltrifluorosilane (CF3CH2CH2SiF3) were obtained in the vapour, amorphous and crystalline solid phases in the range 4000–50 cm−1. Additional spectra in argon and nitrogen matrices at 4.8 K were recorded before and after annealing to temperatures of 20–36 K. Raman spectra of the compound as a liquid were recorded at various temperatures between 298 and 163 K and spectra of the amorphous and crystalline solids were obtained. The spectra revealed the existence of two conformers (anti and gauche) in the fluid phases and in the matrices. When the vapour was shock‐frozen on a cold‐finger at 78 K and subsequently annealed to 120–150 K, 12 mostly weak Raman bands vanished in the crystal. Much smaller variations were observed in the corresponding infrared spectra after annealing. However, the spectra indicated the existence of two different crystals, formed after annealing the amorphous solid to 120 and to 150 K; both crystals contained the same conformer (anti). Raman and IR spectra of 1,1,1‐trifluoropropyltrifluorosilane in cyclohexane, carbon tetrachloride and acetonitrile revealed conformational displacements with solvent polarity. From intensity variations between 298 and 223 K of the Raman pair 639/665 cm−1, ΔH° (gauche–anti) = 3.4 ± 0.3 kJ mol−1 was obtained in the liquid. Annealing experiments indicate that the anti conformer also has a lower energy in argon and nitrogen matrices; moreover, the low‐energy conformer is present in the crystal. The spectra of both conformers have been interpreted in detail. Ab initio calculations at the HF/6–311(d), HF/6–311 G (3df,3pd) and MP2/G–31(d) levels gave optimized geometries, infrared and Raman intensities and scaled vibrational wavenumbers for the anti and gauche conformers. The conformational energy difference derived was 5.3 kJ mol−1 with anti being the low‐energy conformer. Copyright © 2003 John Wiley & Sons, Ltd.
Detection of single lipid bilayers with coherent anti‐Stokes Raman scattering (CARS) microscopy
Authors: Potma Eric O. , Xie X. S.
Published: September 2003

We investigated vibrational imaging of phospholipid bilayers with CARS microscopy. Single lipid membranes of supported bilayers, giant unilamellar vesicles and intact erythrocyte membrane are detected with the strong resonant signal of the C–H stretching vibration. In addition, it is shown that the CARS signal field of the lipids near the glass/water interface is amplified through mixing with the back‐reflected non‐resonant CARS field of the glass coverslip. Furthermore, interference effects between two separate bilayers are observed, allowing intermembrane distances to be determined beyond the diffraction‐limited resolution of the microscope. Copyright © 2003 John Wiley & Sons, Ltd.
Tip‐enhanced Raman microscopy: practicalities and limitations
Authors: Richards D. , Milner R. G. , Huang F. , Festy F.
Published: September 2003

The feasibility of apertureless scanning near‐field Raman microscopy, exploiting the local enhancement in Raman scattering in the vicinity of a silver or gold tip, was investigated. Using the finite difference time domain method we calculated the enhancement of electric field strength, and hence Raman scattering, achieved through the resonant excitation of local modes in the tip. By modelling the frequency‐dependent dielectric response of the metal tip we were able to highlight the resonant nature of the tip‐ enhancement and determine the excitation wavelength required for the strongest electric field enhancement, and hence Raman scattering intensity, which occurs for the excitation of modes localized at the tip apex. It is demonstrated that a peak Raman enhancement of 107‐fold should be achievable with <5 nm spatial resolution. We show that surface‐enhanced Raman scattering from carbon contamination on a silver or gold tip can be significant. However, we find for a tip of radius of curvature 20 nm that the Raman enhancement should decay totally within 20 nm from the tip. Hence withdrawal of the tip by this distance should lead to the disappearance of the tip‐enhanced signal, leaving only that from carbon contamination on the tip itself and the intrinsic signal from the sample. Copyright © 2003 John Wiley & Sons, Ltd.
Local enhancement of coherent anti‐Stokes Raman scattering by isolated gold nanoparticles
Authors: Ichimura Taro , Hayazawa Norihiko , Hashimoto Mamoru , Inouye Yasushi , Kawata Satoshi
Published: September 2003

We observed local enhancement of coherent anti‐Stokes Raman scattering (CARS) by isolated gold nanoparticles. CARS signals from adenine molecules of a DNA base attached to isolated gold nanoparticles were strongly enhanced owing to the electromagnetic enhancement at the local proximity of the particles. The localization of the enhancement was successfully observed by a CARS microscope using a collinear configuration of tightly focused lasers. The CARS spectrum of adenine was enhanced by a factor of 2000 and was in good agreement with the measured spontaneous Raman spectrum. Copyright © 2003 John Wiley & Sons, Ltd.
The electric field at the apex of a near‐field probe: implications for nano‐Raman spectroscopy
Authors: Hallen H. D. , Jahncke C. L.
Published: September 2003

Near‐field or nano‐Raman spectroscopy is different from its far‐field counterpart in several important respects. We present a unified view of nano‐Raman spectroscopy that accounts for these differences, which include surface enhancement, propagation differences, the presence of z‐polarized light, and electric field gradients that give rise to new spectroscopic selection rules. We also discuss some of the recent advances in near‐field scanning optical microscopy (NSOM) and their positive impact on nano‐Raman spectroscopy. In particular, progress has been made in fabricating better probes, both apertured and apertureless, for NSOM, resulting in larger signal levels important for Raman spectroscopy. Larger signals result in shorter imaging times, the ability to achieve higher resolution and broader applicability of the technique. Copyright © 2003 John Wiley & Sons, Ltd.
Near‐field scanning Raman microscopy using apertureless probes
Authors: Sun W. X. , Shen Z. X.
Published: September 2003

We describe an apertureless near‐field scanning Raman microscope in reflection geometry developed by integrating a near‐field scanning optical microscope and a Raman spectrometer. This set‐up offers some unique features that make it applicable to more samples. The fabrication of the metal tips is also explained in detail. Near‐field Raman mappings have been realized on real silicon devices for the first time. The results illustrate the capability of our near‐field Raman microscope in 2D Raman imaging. The apertureless configuration is a breakthrough to the limitation set by the low optical throughput of metal‐coated optical fiber tips, reducing drastically the integration time for Raman spectra. The reflection scattering geometry makes the system applicable to any samples without preparation. Copyright © 2003 John Wiley & Sons, Ltd.
Cell wall composition of vascular and parenchyma tissues in broccoli stems
Authors: Müller S , Jardine WG , Evans BW , Viëtor RJ , Snape CE , Jarvis MC
Published: September 2003

Broccoli stems can become tough and stringy owing to excessive development of the vascular ring. Thickened cell walls from the vascular ring were isolated and their composition was determined. They were derived principally from anatomically recognisable xylem vessels, fibres and tracheids but contained an assemblage of polysaccharides typical of primary cell walls. Their pectin content was particularly high and they contained only 6% lignin as estimated by solid state 13C NMR spectroscopy. They did not differ markedly in composition from parenchyma cell walls within the same stems. Thus, despite their thickness and anatomical appearance, these cell walls resembled the walls of non‐woody cells in their polymer composition. Copyright © 2003 Society of Chemical Industry
A chromametric method for the rapid assessment of deep frying oil quality
Authors: Xu Xin‐Qing
Published: September 2003

A rapid chromametric method was developed for the assessment of deep frying oil quality based on the strong correlation between colour index and total polar compounds in deep frying oil. Colour indices of frying oil samples, measured by chromameter, decreased significantly during frying and were strongly correlated with frying time (r ≥ 0.95, p < 0.001). Colour indices of a set of oil samples taken from 0 to 80 h of deep frying were also significantly correlated with total polar compounds of the same samples determined using the official method of the American Oil Chemists' Society (r = 0.96, p < 0.001). The equation for conversion of the colour index (x) to the content of total polar compounds (y) in an oil sample is y = 0.0174x2 − 2.9506x + 124.34. In addition, colour indices of 10 different types of frying oils were strongly correlated with the corresponding contents of total polar compounds in the oils with samples taken from 0 to 80 h of deep frying in duplicate (r = 0.95, p < 0.001, n = 220). The results of colour index analyses agreed well with the results of chemical and sensory analyses of the frying oils tested. This chromametric method is rapid, convenient and reliable. Copyright © 2003 Society of Chemical Industry
Structural features of arabinoxylans from Sonalika variety of wheat: comparison between whole wheat flour and wheat bran
Authors: Nandini CD , Salimath PV
Published: September 2003

Arabinoxylans (AX) were extracted from Sonalika variety of wheat (whole wheat flour and wheat bran) with barium hydroxide and sodium hydroxide and purified by a combination of alcohol precipitation and glucoamylase digestion. Structural features of purified AX were elucidated by methylation analysis,13C NMR, FT‐IR, periodate oxidation and optical rotation measurements. The AX showed a backbone of xylose residues with β(1–4) linkages and were branched mainly through O‐3 of xylose residues. Completely branched xylosyl residues were also present. Copyright © 2003 Society of Chemical Industry
Aspergillus species from section Flavi isolated from soil at planting and harvest time in peanut‐growing regions of Argentina
Authors: Barros Germán , Torres Adriana , Palacio Gabriela , Chulze Sofía
Published: September 2003

Aspergillus species from section Flavi were isolated from soil samples in three peanut‐growing regions of Córdoba Province, Argentina. The samples were collected during the planting and harvest periods. Both total fungal population and Aspergillus species from section Flavi showed no significant differences between planting and harvest time in two of the regions evaluated. Only in one region were there significant differences in cfu g−1 of total fungal population and Aspergillus species from section Flavi. A flavus was the dominant species isolated in all three localities during the planting and harvest periods. There were significant differences (p < 0.05) in the ratio of toxigenic and atoxigenic strains dependent on the period and the region evaluated. In one region, higher frequencies of toxigenic A flavus and A parasiticus in soil were found and a high contamination level of aflatoxins was detected in peanut seeds. Copyright © 2003 Society of Chemical Industry
Texture changes in fresh cut celery during refrigerated storage
Authors: Viña Sonia Z , Chaves Alicia R
Published: September 2003

The effect of refrigerated storage temperature (0 or 10 °C) on variations in texture and lignin content of minimally processed celery was assessed. In addition, the evolution of soluble phenols was studied, as well as changes in other quality parameters, namely weight loss, surface colour and contents of chlorophyll and free sugars. To this end, celery cuts were packaged on PVC film‐covered polystyrene trays. The maximum shear force required to cut the strips transversally followed a similar tendency during storage at both temperatures tested. Increases in lignin content were observed which could be related to corresponding texture increases during the first few days in cold storage. There was no evidence that lignification occurred by a cicatrix‐forming process in the wounds caused during cutting. Copyright © 2003 Society of Chemical Industry
Can grafting in tomato plants strengthen resistance to thermal stress?
Authors: Rivero Rosa M , Ruiz Juan M , Romero Luis
Published: September 2003

Grafted and non‐grafted tomato plants were grown at 25 and 35 °C for 30 days. In tomato leaves we analysed total phenols, o‐diphenols, enzymatic activities (PAL, PPO and GPX) and dry weight. Our results indicate that heat stress in both grafted and non‐grafted tomato plants occurred at 35 °C and resulted in (1) increased PAL activity, (2) increased total phenols and o‐diphenols, (3) decreased PPO and GPX activities and (4) decreased dry weight. These results show that high temperature induces the accumulation of phenolics in tomato plants by activating their biosynthesis as well as inhibiting their oxidation. However, the impact of high‐temperature stress was smaller in grafted than in non‐grafted tomato plants. This indicates that grafted plants have a higher degree of resistance against thermal stress if the rootstock is more resistant to thermal stress. Copyright © 2003 Society of Chemical Industry
Effects of Azadirachta excelsa on feeding behaviour, body weight and mortality of Crocidolomia binotalis Zeller (Lepidoptera: Pyralidae)
Authors: Teik Ng Lean , Mun Yuen Pak , Hong Loke Wai , Abdul Kadir Azizol
Published: September 2003

We investigated the effects of methanolic extracts of Azadirachta excelsa wood (SWE) at concentrations of 5, 10 and 20 g l−1 against Crocidolomia binotalis. Second instars were fed a diet of cabbage leaves treated with SWE or were contacted topically with SWE. The results indicated that SWE produced significant (p < 0.05) antifeedant and contact toxicity effects. However, among the different treatments, a lesser effect on pupal weight was noted in the contact toxicity test. In most instances, untreated leaves were severely damaged, whereas leaves treated with SWE were not attacked or were only slightly damaged. Although both methods of SWE treatment caused a significantly high mortality rate, there was no difference in dose response in the range studied. Thus SWE at a concentration of 5 g l−1 was shown to be as active as that at 20 g l−1. The results indicate that SWE is a potent antifeedant and also has toxicity against C binotalis. Copyright © 2003 Society of Chemical Industry
Discrimination of cucumber cultivars using a multiple‐point sheet sensor to measure biting force
Authors: Dan Haruka , Okuhara Kazutake , Kohyama Kaoru
Published: September 2003

To define the textural differences among three cucumber cultivars, we combined two different mechanical measurements: a direct measurement of mastication force using a multiple‐point sheet sensor (MSS), and a uniaxial compression test. For mastication force measurement, subjects bit a sample placed on the sheet sensor with their upper and lower incisors. During a single bite, masticatory force was measured using a computerised MSS device called the ISCAN system with a TSCAN sheet sensor. Values of maximum bite force, the time at which maximum bite force appeared, area under the force–time curve, contact area and maximum pressure point for one cultivar were significantly higher than those for the other two. For all the parameters, lower values corresponded to crispness and higher values to toughness. Overall tendencies were the same in the compression test, though the compression test tends to yield smaller standard deviations. The MSS masticatory test is suitable for analysing masticatory properties with respect to each individual, while the instrument test is suitable for analysing physical properties inherent in each sample. Combination of the actual mastication test performed in the human oral cavity and conventional mechanical tests provides the most reliable objective analysis of food texture. Copyright © 2003 Society of Chemical Industry
Bouillon cubes: assessment of the state of degradation of the lipid fraction
Authors: Caponio Francesco , Gomes Tommaso , Bilancia Maria Teresa
Published: September 2003

An experimental investigation was carried out to assess the oxidative and hydrolytic quality of the lipid fraction of bouillon cubes. Besides the routine analyses prescribed by EC regulations, determinations of fatty acid composition and unsaturated fatty acid trans isomers were also performed. From the lipid fraction extracted from each cube, polar compounds were separated by silica gel column chromatography and then submitted to HPSEC (high‐performance size exclusion chromatography) analysis to determine the classes of substances deriving from oxidation, polymerisation and hydrolysis of triglycerides. The data obtained showed that the determination of trans isomers and the subsequent HPSEC analysis of polar compounds enable one to ascertain the actual degradation of the lipid fraction of such food preparations. The degree of degradation of the lipid fraction of bouillon cubes was similar to that normally found in olive‐pomace oil, which is the poorest olive oil commercial class. Finally, the contents of trans isomers and triglyceride oligopolymers are shown to be significantly higher in hydrogenated than in non‐hydrogenated vegetable fats. Copyright © 2003 Society of Chemical Industry
Analytical composition and rumen degradability of isogenic and transgenic corn varieties
Authors: Rossi F , Moschini M , Fiorentini L , Masoero F , Piva G
Published: September 2003

Two different corn cultivars were compared with their genetically modified counterparts containing the gene coding for the Cry1A(b) protein of Bacillus thuringiensis (Bt). There were no analytical differences between the conventional and transgenic genotype kernels, whereas stovers from Bt+ plants had higher sugar (148.3 g kg−1 versus 115.9 g kg−1; P < 0.01) and lower NDF (592.7 g kg−1 versus 631.5 g kg−1; P < 0.05) contents than Bt− maize. A comparison of the amino acid profiles showed higher phenylalanine content in kernels from the Bt+ plants (49.1 g kg−1 vs 47.8 g kg−1; P < 0.05) which was, however, not reflected in the protein content. The initial dry matter rumen degradability of the isogenic kernels was higher than that of Bt+ varieties (569.5 g kg−1 vs 543.7 g kg−1; P < 0.05), whereas the lower fibre content increased the dry matter (548.6 g kg−1 vs 526.6 g kg−1; P < 0.01) and protein (695.6 g kg−1 vs 647.9 g kg−1; P < 0.01) degradability after 24 h of incubation in stovers from Bt+ plants. The NDF degradability was higher in Bt− corn varieties because of the higher proportion of hemicellulose in the total fibre. Copyright © 2003 Society of Chemical Industry
Uptake of fluoride by tea plant (Camellia sinensis L) and the impact of aluminium
Authors: Ruan Jianyun , Ma Lifeng , Shi Yuanzhi , Han Wenyan
Published: September 2003

Tea plant (Camellia sinensis L) accumulates large amounts of fluoride in mature leaves from soils of normal fluoride availabilities, but the properties of fluoride absorption by this plant species are not well understood. The present study examined the characteristic of fluoride uptake by tea plants and the impact of Al with solution and soil experiments. The results showed that the fluoride taken up by tea plants was largely and readily transported, in particular to the leaves. The fluoride in leaves increased linearly with fluoride concentrations in the uptake solution (R2 = 0.75, P < 0.001) or in the soil (R2 = 0.88, P < 0.001), whereas those in root and stem were only marginally influenced. Including Al in solution or adding Al to the soil apparently increased the uptake and translocation of fluoride to the leaves. The concentrations of fluoride in the leaves were significantly (P < 0.05) increased by 19.1% or 37.7% when 18.5 µmol l−1 Al or 74.1 µmol l−1 Al respectively was included in the uptake solution, compared with the control without Al during an uptake period of 22 h. Similarly, Al application (100 mg kg−1) to soil led to significantly higher fluoride concentrations in mature leaves and new shoots (one bud with three leaves). By contrast, the concentrations of Al in leaves in solution and soil experiments were not affected by fluoride and Al treatments. Nevertheless, higher Al concentrations after Al and fluoride additions were observed in the new shoots in soil experiments. Copyright © 2003 Society of Chemical Industry
Supercritical CO2 extraction of Chilean hop (Humulus lupulus) ecotypes
Authors: del Valle José M , Rivera Oscar , Teuber Osvaldo , Palma M Teresa
Published: September 2003

Hops (Humulus lupulus L) have very stringent requirements of diurnal light hours during flowering. Thus, the beer industry is permanently assessing new agricultural land to grow hops, southern Chile being an excellent candidate for their introduction. Supercritical carbon dioxide extraction procedures were implemented to assess Chilean hop ecotypes. Based on results of a preliminary study with commercial samples (cv Nugget), 200 bar and 40 °C were selected as extraction conditions. Very limited increases in extraction rate were observed when applying pressures >200 bar; such pressures did not speed up the extraction of α‐acids (bitter flavor principles), but rather increased the co‐extraction of undesirable compounds (hard resins and chlorophyll pigments). On the other hand, the effects of retrograde condensation phenomena were just starting to subside at 200 bar, and thermal damage of samples could increase at >40 °C. Ground cone samples of five local hop ecotypes, originating from Osorno, La Junta, Coyhaique and Elizalde Lake, were subsequently tested. Osorno exhibited a higher yield (65 g kg−1 oleoresin/substrate) than other Chilean ecotypes. Moreover, Osorno extract had a light yellowish color, as well as a higher content of bitter flavors (157 g kg−1 α‐acid/extract) and 1.5–7.1 times more representative aroma compounds than extracts of the other ecotypes. However, all these indicators were very low compared with the commercial Nugget sample (134 g kg−1 oleoresin/substrate, 383 g kg−1 α‐acid/extract, 14 times more aroma compounds than Osorno ecotype). Copyright © 2003 Society of Chemical Industry