bluuebunny/crossref_metadata_2025_split huggingface dataset:
Stripping Voltammetry with Bismuth Modified Graphite‐Epoxy Composite Electrodes
Authors: Kırgöz Ülkü Anık , Marín Sergi , Pumera Martin , Merkoçi Arben , Alegret Salvador 
Published: February 2005

AbstractThe attractive performance of graphite‐epoxy composite electrodes (GECE) surface‐modified with a bismuth film (Bi‐GECE) for simultaneous and separate stripping determination of trace amounts of heavy metals (lead, cadmium and zinc) is described. Several key parameters have been optimized. Bi‐GECEi electrode shows superior accumulation properties when compared to bare GECE or even to Hg‐GECE. Bi‐GECE exhibits well‐defined, undistorted, reproducible and sharp stripping signals with RSD of 2.99%, 1.56% and 2.19% for lead, cadmium and zinc respectively. Detection limits of 23.1, 2.2 and 600 μg/L for lead, cadmium and zinc were obtained. Sharp peaks with high resolution (of neighboring signals) that permit convenient multi‐elemental measurements resulted. The applicability of the electrodes to the real samples (tap water and soil sample) was also tested and promising results with good recoveries were obtained.
Silicon Micromachined Infrared Thin‐Layer Cell for In Situ Spectroelectrochemical Analysis of Aqueous and Nonaqueous Solvent System
Authors: Yun Kwang‐Seok , Joo Segyeong , Kim Hong‐Jeong , Kwak Juhyoun , Yoon Euisik 
Published: February 2005

AbstractThis article reports in situ FTIR monitoring of electrochemical reactions using a silicon‐based thin‐layer cell realized by micromachining fabrication technologies. The proposed device contains a silicon micromachined cavity cell integrated with a gold working electrode, a counter electrode, and a Ag/AgCl reference electrode. Electrochemical, spectroscopic, and spectroelectrochemical characteristics of the fabricated cell have been experimentally measured and exhibited a comparable performance to commercialized CaF2 thin‐layer cells. In situ spectroelectrochemical characteristics have been successfully tested for both 2 mM K3Fe(CN)6 in an aqueous solution and 2 mM ferrocene in a dichloromethane solution using the fabricated thin‐layer cell.
Direct Simultaneous Determination of Cu, Ni and V in Seawater Using Adsorptive Cathodic Stripping Voltammetry with Mixed Ligands
Authors: Cobelo‐García A. , Santos‐Echeandía J. , Prego R. , Nieto O. 
Published: February 2005

AbstractAn analytical procedure is proposed for the direct simultaneous determination in a single scan of Cu, Ni and V in seawater by means of adsorptive cathodic stripping voltammetry (ACSV) with mixed ligands (DMG and catechol). Optimum conditions for the determination of these three elements were studied. Detection limits of the technique depended upon the reproducibility of the procedura blank, and were found to be 0.5 nM for Cu, 0.4 nM for Ni and 0.3 nM for V. The method is suitable for the analysis of estuarine, coastal and open‐ocean waters, and especially to study the metal contamination in areas subject to oil spill events.
Electrochemical Reduction of Pyridinic Herbicides Picloram and Clopyralid on a Mercury Pool Electrode
Authors: Rodríguez Mellado J. M. , Corredor M. C. , Pospíšil L. , Hromadová M. 
Published: February 2005

AbstractThis paper presents the identification by GC/MS of the products obtained after the total reduction of picloram and clopyralid on a mercury pool electrode. The products found in the strongly acidic media reduction of picloram are 4‐amino‐3,5,6‐trichloro‐2‐pyridinecarboxaldehyde, 4‐amino‐3,5,6‐trichloro‐2‐pyridinecarbinol and 4‐amino‐3,5‐dichloro‐2‐pyridinecarboxylic acid; at pH 3–4 the first compound is substituted by 4‐amino‐3,5‐dichloro‐2‐pyridinecarboxaldehyde. For clopyralid 3,6‐dichloro‐2‐pyridinecarbinol was detected. Under the light of such products the overall reduction processes are discussed showing the partial reductive cleavage of chlorine atoms in both cases.
EWSR1 is fused to POU5F1 in a bone tumor with translocation t(6;22)(p21;q12)
Authors: Yamaguchi Shuichi , Yamazaki Yukari , Ishikawa Yuichi , Kawaguchi Noriyoshi , Mukai Hiroyuki , Nakamura Takuro 
Published: February 2005

AbstractPOU5F1(OCT3/4) is a sequence‐specific transcription factor that is essential for keeping germ cells and embryonic stem cells in an immature and pluripotent status. In this article, we report that POU5F1 was fused to EWSR1 in a case of undifferentiated sarcoma derived from pelvic bone with chromosomal translocation t(6;22)(p21;q12). The EWSR1–POU5F1 chimera consists of exons 1–6 of EWSR1 and exons 2–5 and a part of exon 1 of POU5F1. The predicted amino acid sequence indicates that the chimera is composed of the N‐terminal QSY domain of EWS that functions as a transcriptional activation domain and the C‐terminal POU DNA‐binding domains derived from POU5F1. The t(6;22) tumor does not belong to any known categories of bone and soft‐tissue tumors (BSTs). It is suggested that EWS–POU5F1 may act as an oncogenic transcription factor and that its expression may contribute to undifferentiated and immature phenotypes of BST. © 2005 Wiley‐Liss, Inc.
Reduced risk of prostate cancer in men who are childless as compared to those who have fathered a child: A population based case‐control study
Authors: Giwercman Aleksander , Richiardi Lorenzo , Kaijser Magnus , Ekbom Anders , Akre Olof 
Published: February 2005

AbstractAndrogens are believed to play a major role in the etiology of prostate cancer, but studies of sex‐hormone exposure in relation to risk for prostate cancer have been inconclusive. Male fertility may be an indicator of long‐term androgen status. To study the role of testicular function in prostate cancer development, we have assessed number of biological children in relation to risk for this malignancy. We carried out a population‐based case‐control study with retrospective ascertainment of cases occurring in Sweden between 1958–98. In total, 48,850 cases of prostate cancer were identified through the nation‐wide Cancer Registry. For each case, one control, matched by year of birth, was randomly selected from the Swedish population. Information on offspring was obtained from the Swedish Multi‐Generation Registry. We estimated odds ratios (OR) and 95% confidence intervals (CI) for the association between number of offspring and risk for subsequent prostate cancer. Being childless or having fathered one child only were associated with reduced risks for prostate cancer compared to having fathered 2 or more children (OR = 0.83; 95% CI = 0.81–0.86 and OR = 0.93; 95% CI = 0.90–0.96, respectively). There was no further change in risk associated with fathering of more than 2 children. The risk for prostate cancer is reduced among childless men. A dysfunctioning reproductive apparatus fueling to a lesser extent prostatic growth, could be a plausible mechanism of this association. © 2005 Wiley‐Liss, Inc.
Pilot screening programme for small molecule activators of p53
Authors: Berkson Rachel G. , Hollick Jonathan J. , Westwood Nicholas J. , Woods Julie A. , Lane David P. , Lain Sonia 
Published: February 2005

AbstractActivation of the p53 tumour suppressor is predicted to have therapeutically beneficial effects. Many current anti‐cancer therapies activate the p53 response via DNA damage. Non‐genotoxic activation of the p53 pathway would open the way to long‐term and possibly prophylactic treatments. We have established a simple protocol to screen small compound libraries for activators of p53‐dependent transcription, and to select and characterise the most interesting hits, which include non‐genotoxic activators. These compounds or their derivatives are of potential clinical interest. This approach may also lead to the identification of novel p53‐activating compound families and possibly to the description of novel molecular pathways regulating p53 activity. © 2005 Wiley‐Liss, Inc.
Ly6 family member C4.4A binds laminins 1 and 5, associates with galectin‐3 and supports cell migration
Authors: Paret Claudia , Bourouba Mehdi , Beer Alexander , Miyazaki Kaoru , Schnölzer Martina , Fiedler Sabine , Zöller Margot 
Published: February 2005

AbstractC4.4A is a member of the Ly6 family, with low homology to uPAR. It has been detected mainly on metastasizing carcinoma cells and proposed to be involved in wound healing. So far, C4.4A has been observed as an orphan receptor, and its functional activity has not been explored. Using recombinant rat C4.4A (rrC4.4A) made in a eukaryotic expression system, we demonstrate by immunohistology that C4.4A ligands are strongly expressed in tissues adjacent to squamous epithelia of, e.g., tongue and esophagus, the expression pattern partly overlapping with laminin (LN) and complementing the C4.4A expression that is found predominantly on the basal layers of squamous epithelium. ELISA screening of several components of the extracellular matrix revealed selective binding of rrC4.4A to LN1 and LN5 and that transfection of the BSp73AS tumor line with C4.4A cDNA (BSp73AS‐1B1) promoted LN1 and LN5 binding. Binding of BSp73AS‐1B1 to LN5 and, less markedly, LN1 induced spreading, lamellipodia formation and migration. C4.4A also associates with galectin‐3 in nontransformed tissues and tumor lines. There is evidence that the association of C4.4A with galectin‐3 influences LN adhesion. C4.4A was described originally as a metastasis‐associated molecule. Our findings that LN1 and LN5 are C4.4A ligands, that galectin‐3 associates with C4.4A and that C4.4A ligand binding confers a migratory phenotype are well in line with the supposed metastasis association. © 2005 Wiley‐Liss, Inc.
Enzymatic detection of precursor cell populations of preneoplastic foci positive for γ‐glutamyltranspeptidase in rat liver
Authors: Satoh Kimihiko , Takahashi Gen , Miura Tomisato , Hayakari Makoto , Hatayama Ichiro 
Published: February 2005

AbstractAn improved staining method for γ‐glutamyltranspeptidase (GGT) was developed using Vibratome‐prepared microslices. Microscopic precursor cell populations of preneoplastic foci positive for the marker enzyme were detectable sequentially in rat liver by tracing back from 5 to 1 week after carcinogen injection in a hepatocarcinogenesis model. Mirror‐image comparisons of serial sections stained for GGT activity and immunocytochemically stained for GST‐P (glutathione S‐transferase P‐form) revealed that GGT expression was confined within GST‐P+ cell populations (GST‐P+ minifoci), which are induced in the periportal area (zone 1) of the liver. GGT expression level differed from one minifocus to another, and the larger the GST‐P+ focus, the stronger was the GGT expression in it, indicating that GST‐P+/GGT− phenotypes are convertible into proliferating GST‐P+/GGT+ ones. Our results suggest that there are at least 2 closely related precursors, GST‐P+/GGT− and GST‐P+/GGT+ phenotypes, of preneoplastic foci in rat chemical hepatocarcinogenesis. © 2005 Wiley‐Liss, Inc.
How does Sarbanes‐Oxley affect outsourcing?
Authors: Cannon David M. , Growe Glenn A. 
Published: February 2005

AbstractOutsourcing has been a favorite way for many companies to cut costs. But the recently passed Sarbanes‐Oxley Act may mean problems. Management must maintain an effective system of internal control over financial reporting. And this responsibility cannot be transferred to external entities. © 2005 Wiley Periodicals, Inc.
Liquid nitrogen‐based quick freezing: Experiences with bounce‐free delivery of cholinergic nerve terminals to a metal surface
Authors: Phillips Thomas E. , Boyne Alan F. 
Published: February 2005

AbstractThe limitations of chemical fixation in permitting the 1:1 quantitative correlations required for convincing ultrastructural explanations of cell biological processes are noted. We describe techniques for obtaining highly reproducible direct quick freezing on the polished surface of pure copper bars dipping into a static dewar of liquid N2. The importance and the ease of testing and obtaining bounce suppression with commerically available equipment is emphasized. Artefacts caused by tissue damage and bad freezing are illustrated, and a hitherto unrecognized population of presynaptic membrane attached vesicles is described in Torpedine electric organ. Between 15 and 20% of the synaptic vesicles are attached to ca. 30% of the cytoplasmic face of the presynaptic terminal membrane. There is a close correlation between the occurrence of such attachments and the application of electrocyte basal lamina to the external face. We suggest that these vesicles are the ‘membrane operators,’ ‘vesigates,’ and ‘highly active subpopulation’ of vesicles whose existence has been invoked to explain biochemical data in other laboratories. We further speculate that relatively selective Ca pumping by this immediately submembranous population leads to displacement of acetylcholine (ACh) and reloading with newly synthesized ACh. The preferential release of the latter would then be expected.
The preparation of cross‐section specimens for transmission electron microscopy
Authors: Bravman John C. , Sinclair Robert 
Published: February 2005

AbstractThe structure and chemistry of thin solid films are best studied by transmission electron microscopy (TEM) when they are viewed in cross‐section—that is, when the surface normal of the film is made perpendicular to the electron beam. In this orientation, the substrate, the thin film layers, and the interfaces between them can be imaged either simultaneously or individually. Further, information from each of these regions remains distinct from that obtained from the others, eliminating the problems of superimposition that are a consequence of viewing a layered structure in the conventional manner (i.e., parallel to the surface normal). A technique for fabricating TEM specimens that can be viewed in cross‐section is described here. Although the majority of our work is with silicon‐based materials, the technique can be readily adapted to the study of other systems.
Continuous serial thin sectioning for electron microscopy
Authors: Fahrenbach Wolf H. 
Published: February 2005

AbstractThe process of serial sectioning for electron microscopy has been refined such that loss of thin sections is kept below 0.1% and the series is continued at will. The method relies on microscopic control of all manipulative steps, Formvar casting on plate glass for coated slot grids, coating of the block with contact cement for reliable ribboning, pickup by a one‐step method with grid support in the diamond knife trough, staining in LKB grid holders, gentle treatment of grids in the electron microscope, and a slight modification to the microscope for safe grid withdrawal. The results are particularly applicable to the reconstruction of neuronal microcircuits and larger volumes of neuropil.
Ion milling of materials science specimens for electron microscopy: A review
Authors: Howitt D. G. 
Published: February 2005

AbstractIon bombardment to perforation is a common technique in the materials sciences by which thin specimens can be prepared for transmission electron microscopy. The process is not without complication and involves radiation damage to the specimen and tends not to preserve the initial specimen topology. Some of the more important facets of the ion‐milling process, pertinent to such specimen preparations, are described.
Some aspects of field emission and field ion microscopy
Authors: Tsong T. T. 
Published: February 2005

AbstractThe field emission microscope can reveal the work function variation of an emitter surface with a spatial resolution of ∼ 25 Å. It is particularly powerful for studying adsorption‐desorption and surface diffusion phenomena. The field ion microscope can resolve single atoms on solid surfaces. Structures of deeper surface layers can be revealed by field evaporation. The chemical identity of surface atoms can be analyzed one by one by time‐of‐flight mass spectrometry in the atom probe. Using these two instruments, behavior of single atoms on metal surface, compositional variations in the surface layers of alloys, and the atomic structures as well as compositional variations of various phases in alloys and materials can be studied with true single atomic layer, spatial resolution. Some aspects of field emission techniques and applications of them to surface science and material characterization are described here.
Maximum‐likelihood estimation applied to electron microscopic autoradiography
Authors: Miller Michael I. , Larson Kenneth B. , Saffitz Jeffrey E. , Snyder Donald L. , Thomas Lewis J. 
Published: February 2005

AbstractA new method for analysis of electron microscope autoradiographs is described which is based on the maximum‐likelihood method of statistics for estimating the intensities of radioactivity in organelle structures. We adopted a Poisson statistical model to describe the autoradiographic grain distributions that we prove results from the underlying Poisson nature of the radioactive decays as well as the additive errors introduced during the formation of grains. Within the model, an interative procedure derived from the expectation‐maximization algorithm of mathematical statistics is used to generate the maximum‐likelihood estimates. The algorithm has the properties that at every stage of the iteration process the likelihood of the data increases; and for all initial nonzero starting points the algorithm converges to the maximum‐likelihood estimates of the organelle intensities.The maximum‐likelihood approach differs from the mask‐analysis method, and other published quantitative algorithms in the following ways: (1) In deriving estimates of the radioactivity intensities the maximum‐likelihood algorithm requires that we obtain the actual locations of the grains as well as the micrograph geometries; each micrograph is digitized so that both the grain locations as well as the geometries of the organelle structures can be used. (2) The maximum‐likelihood algorithm iteratively computes the minimum‐meansquared‐error estimate of the underlying emission locations that resulted in the observed grain distributions, from which intensity estimates are generated; this algorithm does not minimize a chi‐squared error statistic. (3) The maximum‐likelihood approach is based on a Poisson model and is therefore valid for low‐count experiments; there are no minimum constraints on data collection for any single organelle compartment. (4) The maximum‐likelihood algorithm requires the form of the point‐spread function describing the emission spread; a probability matrix based on the use of overlay masks is not required. (5) The maximum‐likelihood algorithm does not change for different organelle geometries; arbitrary geometries are incorporated by maximizing the likelihood‐function subject to the geometry constraints.We have performed a preliminary evaluation of the quantitative accuracy of the maximum‐likelihood and mask‐analysis algorithms. Based on two different phantoms in which we compared the squared error resulting from the two algorithms, we find that the new maximum‐likelihood approach provides substantially improved estimates of the radioactivity intensities of the phantoms.
Transmission electron microscopy of catalysts
Authors: Sanders J. V. 
Published: February 2005

AbstractThe determination of the structures of catalysts is an important step in understanding their behaviour and in developing new or improved catalysts. By their nature, catalysts mostly have a structure which can be resolved only by transmission electron microscopy (TEM) used near its limit of applicability. This article discusses recent selected examples of the use of TEM to examine materials used as catalysts, such as clusters of atoms, small crystalline particles, the materials (oxides) on which these are supported, zeolites, and deposits of carbon which often form on catalysts during catalytic reactions. Interpretation of the images is often aided by the techniques of image processing.
Application of ion beam sputtering for high‐resolution electron microscopy
Authors: Kanaya Koichi , Baba Norio , Muranaka Yoshinori , Adachi Koichi 
Published: February 2005

AbstractIon beam sputtering for high‐resolution electron microscopy has basically provided miscellaneous operational features such as atomic shadowing, uncoated observation, and etching of biological specimens coupled with tungsten sputter coating and thinning of solid materials.Based on the power‐potential law of Lindhard for ionic impact phenomena on metal surfaces, the universal yield‐energy relationship has been derived. Thereby the sputtering deposition rate with reference to the sputtering removal rate was obtained as a function of sputtering yield, and the most important angular distribution of sputtering yield could be measured by using the hemicylindrical specimen stage.Evidence is presented to show that ion beam sputtering has become one of the most powerful tools for high‐resolution electron microscopy.
Cross‐Section preparation for tem of film‐substrate combinations with a large difference in sputtering yields
Authors: Helmersson Ulf , Sundgren Jan‐Eric 
Published: February 2005

AbstractThe preparation of cross‐section samples of thin films for TEM, may be difficult and tedious, especially if the difference in chemical or physical etching rates is large between the film and the substrate. In this paper, a method is presented whereby cross‐sections can be prepared even if the film and the substrate have a large difference in sputtering yield. By utilizing the strong angular dependence of the sputtering yield and sputter at a low ion incidence angle with respect to the substrate surface of 7–12° and, furthermore, by avoiding sputtering parallel to the interface, samples with homogeneous thickness can be obtained. The technique is demonstrated on reactively sputtered titanium nitride coatings on high speed steel substrates. The difference in sputtering yields is about three for this film‐substrate combination with the substrate being sputtered fastest.
Contamination of thin sections: Some observations on the cause and elimination of “embedding pepper”
Authors: Mollenhauer Hilton H. 
Published: February 2005

AbstractA method is described for eliminating a form of contamination called embedding pepper that appears in, or on, thin sections following poststaining in lead citrate. The pepper is present most often in the matrixes of mitochondria, peroxisomes, and red blood cells. Formation of pepper can be prevented by treating the section with 0.5 N HCl or 1.0% ethylenediaminete‐traacetic acid (EDTA) for 1–5 min before staining in uranyl acetate or lead citrate.
Observations on the ultrastructural preservation of the nucleus in the myxomycete Physarum polycephalum as observed in resinless sections
Authors: Lachapelle Mario , Lafontaine Jean G. 
Published: February 2005

AbstractThe ultrastructural preservation of the nucleus in both myxamoebae and macroplasmodia of the slime mold Physarum polycephalum was investigated using specimens processed with diethylene glycol distearate or Plexiglass. Following specimen embedding in either of these media, the polymers were dissolved from the semithin sections, which were then dried by the critical point process. In these resinless preparations, nuclei appeared to be pervaded by a complex network of fibrils of various diameters among which granules of different sizes were scattered. At least five different types of fibrils were detected in plasmodial as well as in amoebal nuclei. Resinless preparations obtained from diethylene glycol distearate processed specimens showed a number of easily recognized artifacts, some of which were noticeably less conspicuous when samples were embedded in Plexiglass. In both cases, no indication was obtained that extensive extraction of material had occurred during resin removal by solvents. The various artifacts that were produced following processing with these two media thus seem to have mostly developed during infiltration and hardening, rather than during dissolution of the polymers or critical point drying of the sections.