bluuebunny/crossref_metadata_2025_split huggingface dataset:
Human exposure by mobile phones in enclosed areas
Authors: Toropainen Anssi 
Published: December 2002

AbstractHuman exposure by mobile phones in enclosed areas such as train carriages, elevators, and cars is considered. Equivalent power density and whole body specific absorption rate (SAR) are estimated by applying multimode resonant cavity theory and a straight forward worst case approach. The results show that exceeding the International Commission on Non‐Ionizing Radiation Protection (ICNIRP) guidelines due to simultaneous use of several mobile phones in enclosed areas is highly improbable. Bioelectromagnetics 24:63–65, 2003. © 2002 Wiley‐Liss, Inc.
The wonders of magnetism
Authors: Tenforde Thomas S. 
Published: December 2002

AbstractIn this acceptance address for the Bioelectromagnetics Society's 2001 d'Arsonval Award, Dr. Tenforde reviews the highlights of the nonionizing field aspects of his research and scientific service career. These are focused in four areas: (a) development and application of microelectrophoretic methods to probe the surface chemistry of normal and cancerous cells; (b) research on the biophysical mechanisms of interaction and the dosimetry of static and extremely low frequency magnetic fields; (c) application of extremely high intensity magnetic fields in several spectroscopic methods for probing the detailed structures of large biological macromolecules; and (d) development of national and international guidelines for the exposure of workers and members of the general public to electromagnetic fields with frequencies spanning the entire nonionizing electromagnetic spectrum. Bioelectromagnetics 24:3–11, 2003. © 2002 Wiley‐Liss, Inc.
Chemistry and biology of the ramoplanin family of peptide antibiotics
Authors: McCafferty Dewey G. , Cudic Predrag , Frankel Brenda A. , Barkallah Salim , Kruger Ryan G. , Li Wenkai 
Published: December 2002

AbstractThe peptide antibiotic ramoplanin factor A2 is a promising clinical candidate for treatment of Gram‐positive bacterial infections that are resistant to antibiotics such as glycopeptides, macrolides, and penicillins. Since its discovery in 1984, no clinical or laboratory‐generated resistance to this antibiotic has been reported. The mechanism of action of ramoplanin involves sequestration of peptidoglycan biosynthesis Lipid intermediates, thus physically occluding these substrates from proper utilization by the late‐stage peptidoglycan biosynthesis enzymes MurG and the transglycosylases (TGases). Ramoplanin is structurally related to two cell wall active lipodepsipeptide antibiotics, janiemycin, and enduracidin, and is functionally related to members of the lantibiotic class of antimicrobial peptides (mersacidin, actagardine, nisin, and epidermin) and glycopeptide antibiotics (vancomycin and teicoplanin). Peptidomimetic chemotherapeutics derived from the ramoplanin sequence may find future use as antibiotics against vancomycin‐resistant Enterococcus faecium (VRE), methicillin‐resistant Staphylococcus aureus (MRSA), and related pathogens. Here we review the chemistry and biology of the ramoplanins including its discovery, structure elucidation, biosynthesis, antimicrobial activity, mechanism of action, and total synthesis. © 2002 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 66: 261–284, 2002
A combinatorial biocatalysis approach to an array of cholic acid derivatives
Authors: Secundo Francesco , Carrea Giacomo , De Amici Marco , Joppolo di Ventimiglia Samuele , Dordick Jonathan S. 
Published: December 2002

AbstractA 39‐member library of bile acid derivatives was prepared starting from 3α,7α,12α‐trihydroxy‐5β‐cholan‐24‐oic acid methyl ester using a combinatorial biocatalytic approach. A regioselective oxidation step, catalyzed by hydroxysteroid dehydrogenases, followed by an acylation step with a series of different acyl donors catalyzed by Candida antarctica lipase B, led to the modification of the bile acid scaffold. Each member of the library was obtained in high purity and good yield. © 2003 Wiley Periodicals, Inc. Biotechnol Bioeng 81: 391–396, 2003.
Messverfahren zur Bestimmung des Staubungsvermögens von dispersen Pulvern
Authors: Hamelmann F. , Schmidt E. 
Published: December 2002

AbstractDisperse Feststoffsysteme setzen bei ihrer Handhabung, z. B. beim Lagern, Fördern, Mischen, Abfüllen usw., oft Staub frei. Freigesetzte Stäube können die Gesundheit von Menschen gefährden bzw. schädigen, nehmen Einfluss auf die Umwelt und können zu Bränden und Explosionen führen. Das Staubungsverhalten von Pulvern ist dabei von einer Vielzahl von Parametern abhängig, die sowohl das Pulver selbst als auch die Art und Intensität der Beanspruchung kennzeichnen. Dieser Beitrag gibt eine Übersicht über Verfahren, die zur Bestimmung des Staubungsverhaltens entwickelt bzw. verwendet wurden. Die verwendeten Partikelmesstechniken werden vorgestellt und die Verfahren in einer Systematik zusammengefasst.
Hybridverfahren zur Abluftreinigung
Authors: Ohlrogge K. , Herbst M. , Scheel H. , Wind J. , Peinemann K.‐V. 
Published: December 2002

AbstractMembranverfahren haben bei verschiedenen Anwendungen in der Gastrennung einen anerkannten Stand der Technik erreicht. Hierzu gehören die Luftzerlegung zur Inertgasherstellung oder Sauerstoffanreicherung, die Wasserdampfabtrennung aus Druckluft, die Wasserstoff/Kohlenmonoxidtrennung und Wasserstoff/Stickstofftrennung bei der Ammoniaksynthese, die Kohlendioxid/Methantrennung bei der tertiären Ölgewinnung und die Abtrennung organischer Dämpfe aus Abluft oder Prozessgasen in der chemischen Industrie und beim Benzinumschlag. Ein großes Potential für die Anwendung von Membranverfahren liegt in der Abluftreinigung. Durch die Kombination von Membrantrennung und Adsorption können unter wirtschaftlichen und betriebssicheren Bedingungen niedrige Restemissionen erreicht werden.
Die chemische Bindung — Lernhindernisse und mögliche Lernhilfen
Authors: Reiners Christiane S. 
Published: December 2002

AbstractTHE CHEMICAL BOND There is an often‐quoted parable about a group of blind men who are taken to examine an elephant. Each comes in contact with a different part of the elephant and, therefore, draws a different conclusion about its nature: the man examining the trunk thinks, it is some kind of snake, the one touching its leg thinks it is a tree, and so on. The lesson of this story is, of course, that we can have many different views of the same reality, depending on where we are standing and what data we use for our conclusions. The chemical bond is the chemist's “elephant”. Unable to see this construct that they use to explain the aggregation of atoms into molecules, the chemists interpret its existence in terms of their own views of chemistry… To each of these chemists the chemical bond has different descriptors, although they may all be investigating the same molecule. Thus, the chemist concerned with quantum mechanics regards the chemical bond as an interaction of wave functions, the more classical physical chemist sees a balancing of energies and charges among the component atoms, and the organic or inorganic chemist interested in the three‐dimensional structure of the molecule interprets the bonds in terms of the geometry of the overlapping orbitals. [1, S. 190]
Zur Organischen Chemie im Chemieunterricht der höheren Schulen Preußens im 19. Jahrhundert
Authors: Brückmann Jutta 
Published: December 2002

AbstractDIE BEZEICHNUNG „ORGANISCHE CHEMIE”︁ wird zu Beginn des 19. Jahrhunderts erstmals von J. J. Berzelius erwähnt (1806); mit der Umwandlung von Ammoniumcyanat in Harnstoff gelingt F. Wöhler (1828) die Darstellung eines Naturstoffes auf künstlichem Wege. Um 1860 fasst u.a. A. Kekulé die Organische Chemie als Chemie der Kohlenstoffverbindungen nach unserem heutigen Verständnis zusammen. Noch während des gleichen Jahrhunderts entwickelt sie sich zum Hauptwirtschaftszweig der Chemie. Auch auf theoretischem Gebiet übernimmt die Organische Chemie um 1860 durch die Einführung der Wertigkeit und der Strukturformeln die Vorreiterrolle vor der Anorganischen Chemie.
Synaptic density, convergence, and dendritic complexity of prevertebral sympathetic neurons
Authors: Gibbins Ian L. , Teo Ee Hiok , Jobling Phillip , Morris Judy L. 
Published: December 2002

AbstractPrevertebral sympathetic ganglia contain a unique population of final motor neurons receiving convergent synaptic inputs not only from spinal preganglionic neurons, but also from peripheral intestinofugal neurons projecting from the gut. We used quantitative confocal and ultrastructural immunohistochemistry to determine how this increased synaptic convergence is accommodated by sympathetic final motor neurons in the celiac ganglion of guinea pigs. Terminals of intestinofugal neurons were identified by their immunoreactivity to vasoactive intestinal peptide. Stereologic analyses were based on transects and point counts at confocal and ultrastructural levels. The relative amount of dendritic neuropil in the medial regions of the ganglion was approximately 2.5 times greater than in the lateral regions of the ganglion, consistent with the 2 to 3 times difference in average dendritic field size of neurons in these regions. The total numbers of boutons and synaptic profiles showed significant positive correlations with the relative amount of neuropil in a region. However, the overall density of synaptic boutons was twice as high in the medial region of the ganglion compared with the lateral regions. Because the relative density of preganglionic synapses was similar in each region, this difference was due to the selective projection of intestinofugal inputs to neurons in the medial celiac ganglion, where they provided 45% of synaptic contacts. These results show that, compared with vasoconstrictor neurons, sympathetic neurons regulating gastrointestinal activity support a higher number of convergent inputs in two ways: in addition to having larger dendritic fields, they also have a twofold higher density of synapses. J. Comp. Neurol. 455:285–298, 2003. © 2002 Wiley‐Liss, Inc.
Neuronal development in larval polychaete Phyllodoce maculata (Phyllodocidae)
Authors: Voronezhskaya Elena E. , Tsitrin Eugeni B. , Nezlin Leonid P. 
Published: December 2002

AbstractThe existing view on neuronal development in polychaetes, as undergoing neurogenesis beginning in the rudiments of central ganglia and then extending peripherally, has been contrasted with the latest findings in molluscs, their sister trochozoan group, which show a peripheral to central mode of neurogenesis. The current study addresses this issue by examining early neuronal development in the polychaete Phyllodoce maculata using immunolabeling against acetylated α‐tubulin, serotonin, and the FMRFamide. The first nervous cell was detected 20 hours before hatching, at the early trochophore stage. A solitary serotonergic neuron was located at the posterior‐dorsal extreme of the larva and issued anterior projecting fibers, which outline the future ventral nerve cords and prototroch nerve. Two more serotonergic dorsal peripheral cells and three peripheral FMRFamidergic cells appeared soon thereafter. The fibers of these early cells formed a scaffolding, which prefigured the future adult nervous system (cerebral ganglion, ventral cords, prototroch and esophageal nerve rings) in prehatched trochophores. Shortly before hatching, the larval nervous system developed, including the apical organ, meridianal nerves in the episphere, and posttrochal nerves that innervate the feeding apparatus. After hatching, the rudiments of the adult nervous system started to develop along the paths already established by the earliest peripheral neurons. Thus, the general strategy of neurogenesis in a representative polychaete trochophore appears to resemble that of molluscs. The first neuronal cells to appear are peripheral in origin, located near the posterior margins of the embryo. Their similar anatomical appearance suggests that they share a similar functional role in trochophore development and behavior. J. Comp. Neurol. 455:299–309, 2003. © 2002 Wiley‐Liss, Inc.
Olivocochlear innervation in the mouse: Immunocytochemical maps, crossed versus uncrossed contributions, and transmitter colocalization
Authors: Maison Stéphane F. , Adams Joe C. , Liberman M. Charles 
Published: December 2002

AbstractTo further understand the roles and origins of γ‐aminobutyric acid (GABA) and calcitonin gene‐related peptide (CGRP) in the efferent innervation of the cochlea, we first produced in the mouse an immunocytochemical map of the efferent terminals that contain acetylcholine (ACh), CGRP, and GABA. Olivocochlear (OC) terminals in inner and outer hair cell (IHC and OHC) regions were analyzed quantitatively along the cochlear spiral via light‐microscopic observation of cochlear wholemounts immunostained with antibodies to glutamic acid decarboxylase (GAD), vesicular acetylcholine transporter (VAT), or the peptide CGRP. Further immunochemical characterization was performed in mice with chronic OC transection at the floor of the fourth ventricle to distinguish crossed from uncrossed contributions and, indirectly, the contributions of lateral versus medial components of the OC system. The results in mouse showed that (1) there are prominent GABAergic, cholinergic, and CGRPergic innervations in the OHC and IHC regions, (2) GABA and CGRP are extensively colocalized with ACh in all OC terminals in the IHC and OHC areas, (3) the longitudinal gradient of OC innervation peaks roughly at the 10‐kHz region in the OHC area and is more uniform along the cochlear spiral in the IHC area, (4) in contrast to other mammalian species there is no radial gradient of OC innervation of the OHCs, and (5) all OHC efferent terminals arise from the medial OC system and terminals in the IHC area arise from the lateral OC system. J. Comp. Neurol. 455:406–416, 2003. © 2002 Wiley‐Liss, Inc.
Palmitoyl protein thioesterase 1 is targeted to the axons in neurons
Authors: Ahtiainen Laura , Van Diggelen Otto P. , Jalanko Anu , Kopra Outi 
Published: December 2002

AbstractPalmitoyl protein thioesterase 1 (PPT1) is a depalmitoylating enzyme whose deficiency leads to infantile neuronal ceroid lipofuscinosis. The disease is characterized by early loss of vision and massive neuronal death. Although PPT1 is expressed in many tissues, a deficiency of PPT1 damages neurons only in the cerebral and cerebellar cortexes and retina; other cell types remain relatively unaffected. We previously demonstrated that PPT1 is present in the synaptosomes and synaptic vesicles of neurons. To understand the crucial role of PPT1 for neuronal cells, we further investigated the expression and targeting of PPT1 in retinal, hippocampal, and cortical neurons during their maturation in culture. We found that PPT1 activity increases by neuronal maturation and is highest in retinal neuron cultures. In retinal neurons the expression of PPT1 precedes that of the synaptic vesicle protein 2 and synaptophysin, indicating a significant role for PPT1 in the early development of neuronal cells. We also found by quantitative confocal immunofluorescence microscopy that PPT1 is targeted preferably to axons in mature neurons, as indicated by its colocalization with the axonal marker microtubule‐associated protein 1. In axons PPT1 is targeted specifically to axonal varicosities and presynaptic terminals, as indicated by its significant colocalization with growth‐associated protein 43 and synaptophysin. Axonal localization of PPT1 was confirmed by double labeling with synaptophysin and postembedding immunoelectron microscopy. The polarized axonal targeting of PPT1 may well indicate a role for PPT1 in the exocytotic pathway of neurons. J. Comp. Neurol. 455:368–377, 2003. © 2002 Wiley‐Liss, Inc.
Temporal and spatial profiles of ABCA2‐expressing oligodendrocytes in the developing rat brain
Authors: Tanaka Yukiko , Yamada Katsuya , Zhou Cheng‐Ji , Ban Nobuhiro , Shioda Seiji , Inagaki Nobuya 
Published: December 2002

AbstractABCA2 protein belongs to the ABCA subclass of ATP‐binding cassette (ABC) transporters proposed to exert critical functions in transmembrane transport of endogenous lipids. In this study, we found by immunoblot analyses that approximately 260 kDa of ABCA2 protein is expressed predominantly in oligodendrocytes, and that the expression of the protein is upregulated in the brain during maturation, especially between postnatal days 6 and 19. Parallel to the changes in expression of ABCA2, immunohistochemical analyses showed rapid spatial spread of ABCA2‐immunolabeled oligodendrocytes in the brain during this period. These temporal and spatial changes in ABCA2 expression were in good agreement with findings in myeloarchitectonics reported previously. Further, double immunolabeling with ABCA2 and a major structural protein of myelin, myelin basic protein, demonstrated that onset of ABCA2 expression in oligodendrocytes coincides with the appearance of thick myelin segments immunolabeled with myelin basic protein. Because ABCA2 was abundantly expressed in adult cortex in white matter and gray matter, coexpression of ABCA2 and a marker for the oligodendroglial progenitors NG2 or platelet‐derived growth factor α receptor was investigated. No cells coexpressing ABCA2 and the marker were observed, suggesting that ABCA2 is expressed predominantly in myelin‐forming oligodendrocytes distinct from the adult oligodendroglial progenitors tested. These results suggested a role for ABCA2 in membrane transport of substrates such as the lipids that are closely linked to myelination processes. J. Comp. Neurol. 455:353–367, 2003. © 2002 Wiley‐Liss, Inc.
Developmental changes in the expression of growth hormone‐releasing hormone and pituitary adenylate cyclase‐activating polypeptide in zebrafish
Authors: Krueckl Sandra L. , Fradinger Erica A. , Sherwood Nancy M. 
Published: December 2002

AbstractGrowth hormone‐releasing hormone (GHRH) and pituitary adenylate cyclase‐activating polypeptide (PACAP) are structurally and functionally related members of the glucagon superfamily, a group of hormones important in development, growth, and metabolism. Our objectives were to determine the developmental expression pattern of the ghrh‐pacap1 gene using the zebrafish model. The temporal and spatial expression pattern of the ghrh‐pacap1 gene was examined by RT‐PCR and in situ hybridization. In zebrafish, the ghrh‐pacap1 mRNA transcript was expressed throughout development beginning at the transition between the blastula and gastrula periods. During midgastrulation, alternative splicing resulted in the generation of a novel transcript lacking the cryptic peptide. During the segmentation period, expression was localized to the neural tube, developing eye, and neural crest; strong expression was found in the developing cerebellum. Later in development, expression was localized in the hatching gland and developing pharyngeal arches. The temporal and spatial expression pattern of the ghrh‐pacap1 transcript suggests that these hormones may modulate patterning during development. J. Comp. Neurol. 455:396–405, 2003. © 2002 Wiley‐Liss, Inc.
Saccadic omnipause and burst neurons in monkey and human are ensheathed by perineuronal nets but differ in their expression of calcium‐binding proteins
Authors: Horn Anja K. , Brückner Gert , Härtig Wolfgang , Messoudi Ahmed 
Published: December 2002

AbstractThe extracellular matrix of the brain contains large aggregates of chondroitin sulfate proteoglycans (CSPG), which form lattice‐like cell coatings around distinct neuron populations and are termed perineuronal nets. The function of perineuronal nets is not fully understood, but they are often found around neurons containing the calcium‐binding protein parvalbumin, suggesting a function in primarily highly active neurons. In the present paper the distribution of perineuronal nets was studied in two functional cell groups of the primate oculomotor system with well‐known firing properties: 1) the saccadic omnipause neurons in the nucleus raphe interpositus (RIP) exhibit a high tonic firing rate, which is only interrupted during saccades; they are inhibitory and use glycine as a transmitter; and 2) premotor burst neurons for vertical saccades in the rostral interstitial nucleus of the medial longitudinal fascicle (RiMLF) fire with high‐frequency bursts during saccades; they are excitatory and use glutamate and/or aspartate as a transmitter. In the macaque monkey, both cell populations were identified by their parvalbumin immunoreactivity and were studied for the presence of perineuronal nets using CSPG antibodies or lectin binding with Wisteria floribunda agglutinin. In addition, the expression of another calcium‐binding protein, calretinin, was studied in both cell groups. Double‐ and triple‐immunofluorescence methods revealed that both omnipause and burst neurons are selectively ensheathed with strongly labeled perineuronal nets. Calretinin was coexpressed in at least 70% of the saccadic burst neurons, but not in the omnipause neurons. Parallel staining of human tissue revealed strongly labeled perineuronal nets around the saccadic omnipause and burst neurons, in corresponding brainstem regions, which specifically highlighted these neurons within the poorly structured reticular formation. These findings support the hypothesis that perineuronal nets may provide a specialized microenvironment for highly active neurons to maintain their fast‐spiking activity and are not related to the transmitter or the postsynaptic action of the ensheathed neurons. J. Comp. Neurol. 455:341–352, 2003. © 2002 Wiley‐Liss, Inc.
Fractones and other basal laminae in the hypothalamus
Authors: Mercier Frederic , Kitasako John T. , Hatton Glenn I. 
Published: December 2002

AbstractThe physiological role of basal laminae (BL) and connective tissue (meninges and their projections) in the adult brain is unknown. We recently described novel forms of BL, termed fractones, in the most neurogenic zone of the adult brain, the subependymal layer (SEL) of the lateral ventricle. Here, we investigated the organization of BL throughout the hypothalamus, using confocal and electron microscopy. New types of BL were identified. First, fractones, similar to those found in the lateral ventricle wall, were regularly arranged along the walls of the third ventricle. Fractones consisted of labyrinthine BL projecting from SEL blood vessels to terminate immediately beneath the ependyma. Numerous processes of astrocytes and of microglial cells directly contacted fractones. Second, another form of BL projection, termed anastomotic BL, was found between capillaries in dense capillary beds. The anastomotic BL enclosed extraparenchymal cells that networked with the perivascular cells coursing in the sheaths of adjacent blood vessels. Vimentin immunoreactivity was often detected in the anastomotic BL. In addition, the anastomotic BL overlying macrophages contained numerous fibrils of collagen. We also found that the BL located at the pial surface formed labyrinthine tube‐like structures enclosing numerous fibroblast and astrocyte endfeet, with pouches of collagen fibrils at the interface between the two cell types. We suggest that cytokines and growth factors produced by connective tissue cells might concentrate in BL, where their interactions with extracellular matrix proteins might contribute to their effects on the overlying neural tissue, promoting cytogenesis and morphological changes and participating in neuroendocrine regulation. J. Comp. Neurol. 455:324–340, 2003. © 2002 Wiley‐Liss, Inc.