bluuebunny/crossref_metadata_2025_split huggingface dataset:
Differential winter stemflow generation under contrasting storm conditions in a southern New England broad‐leaved deciduous forest
Authors: Levia Delphis F. 
Published: April 2004

AbstractDespite the importance of stemflow as a hydroecological process, differential winter stemflow generation among and within precipitation types (e.g. snow, rain‐to‐snow) is poorly understood. The purpose of the present study is to understand winter stemflow generation better under contrasting meteorological conditions in a leafless deciduous forest. It is hypothesized that stemflow volume and production, expressed as a funnelling ratio, will differ significantly among and within precipitation event types. Acceptance of this hypothesis would mean that intra‐event meteorological conditions have a significant and discernible effect on stemflow production in deciduous forests, differentially affecting soil moisture, groundwater recharge, soil solution chemistry, and nutrient cycling. Stemflow volumes generated from seven canopy trees were monitored in a leafless deciduous forest of southern New England on a precipitation event basis over two successive winter seasons. Stemflow volume was found to differ significantly among different and same‐type precipitation events. A rain event that occurred on 8 December 1998 and snow‐to‐rain event on 18 January 1999 were of similar duration, magnitude, and intensity, yet produced stemflow volumes that differed by a factor of 4. For two snow‐to‐rain events, stemflow volumes differed by a factor of 11. Stemflow production even varies widely within a discrete precipitation event as a function of meteorological conditions. Significant differential stemflow yield under contrasting storm conditions obviates generalizations concerning stemflow production as a function of precipitation event type and necessitates a deeper, process‐level understanding of winter stemflow generation before modelling exercises are undertaken. Copyright © 2004 John Wiley & Sons, Ltd.
Reduced type I collagen utilization: A pathogenic mechanism in COL5A1 haplo‐insufficient Ehlers–Danlos syndrome
Authors: Wenstrup Richard J. , Florer Jane B. , Cole William G. , Willing Marcia C. , Birk David E. 
Published: April 2004

AbstractTo examine mechanisms by which reduced type V collagen causes weakened connective tissues in the Ehlers–Danlos syndrome (EDS), we examined matrix deposition and collagen fibril morphology in long‐term dermal fibroblast cultures. EDS cells with COL5A1 haplo‐insufficiency deposited less than one‐half of hydroxyproline as collagen compared to control fibroblasts, though total collagen synthesis rates are near‐normal because type V collagen represents a small fraction of collagen synthesized. Cells from patients with osteogenesis imperfecta (OI) and haplo‐insufficiency for proα1(I) chains of type I collagen also incorporated about one‐half the collagen as controls, but this amount was proportional to their reduced rates of total collagen synthesis. Collagen fibril diameter was inversely proportional to type V/type I collagen ratios (EDS > control > OI). However, a reduction of type V collagen, in the EDS derived cells, was associated with the assembly of significantly fewer fibrils compared to control and OI cells. These data indicate that in cell culture, the quantity of collagen fibrils deposited in matrix is highly sensitive to reduction in type V collagen, far out of proportion to type V collagen's contribution to collagen mass. © 2004 Wiley‐Liss, Inc.
Extracellular taurine in the substantia nigra: Taurine‐glutamate interaction
Authors: García Dopico José , Perdomo Díaz Juan , Alonso Teofilo Jorge , González Hernández Tomás , Castro Fuentes Rafael , Rodríguez Díaz Manuel 
Published: April 2004

AbstractTaurine has been proposed as an inhibitory transmitter in the substantia nigra (SN), but the mechanisms involved in its release and uptake remain practically unexplored. We studied the extracellular pool of taurine in the rat's SN by using microdialysis methods, paying particular attention to the taurine–glutamate (GLU) interaction. Extracellular taurine increased after cell depolarization with high‐K+ in a Ca2+‐dependent manner, being modified by the local perfusion of GLU, GLU receptor agonists, and zinc. Nigral administration of taurine increased the extracellular concentration of γ‐aminobutyric acid (GABA) and GLU, the transmitters of the two main inputs of the SN. The modification of the glial metabolism with fluocitrate and L‐methionine sulfoximine also changed the extracellular concentration of taurine. The complex regulation of the extracellular pool of taurine, its interaction with GABA and GLU, and the involvement of glial cells in its regulation suggest a volume transmission role for taurine in the SN. © 2004 Wiley‐Liss, Inc.
Antimicrobial evaluation of fungal extracts produced by endophytic strains ofPhomopsissp.
Authors: Corrado Marcia , Rodrigues Katia F. 
Published: April 2004

AbstractCrude extract of cultures of 13 fungal strains identified asPhomopsissp. and isolated as endophytes from the leaves ofAspidosperma tomentosumand twigs of Spondias mombinwere examined for their antibacterial and antifungal activities. The screening was conducted using the bioautographic TLC agar‐overlay technique against bacteria (E. coli,P. aeruginosa,S. aureus), yeast (C. albicans,S. cerevisiae), and readily adapted for use with filamentous fungi (A. niger,F. oxysporum). Three of the 13 extracts effectively inhibited the growth of all test‐organisms, indicating that they may represent a potential for pharmaceutical and/or agricultural applications and are worthy of further study. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Herstellung von hochporösen, endkonturnahen Titan‐Formkörpern für biomedizinische Anwendungen
Authors: Bram M. , Laptev A. , Buchkremer H.P. , Stöver D. 
Published: April 2004

AbstractDie Herstellung hochporöser Titanformkörper über die Pulvermetallurgie unter Verwendung geeigneter Platzhalterwerkstoffe besitzt eine hohe Attraktivität für biomedizinische Anwendungen. Porositäten bis 75 % und definierte Porengrößen im Bereich von 0,1 bis 2 mm lassen sich direkt über das Mischungsverhältnis und die Partikelgröße des Platzhalters einstellen. Bis jetzt war eine endkonturnahe Formgebung von hochporösen Bauteilen nur eingeschränkt möglich, da bei der mechanischen Bearbeitung von gesinterten Formkörpern die Poren an der Oberfläche durch eine plastische Deformation der Titan‐Stege teilweise oder vollständig verschlossen wurden. Um dies zu vermeiden, wurde ein Verfahren entwickelt, bei dem die Endkontur bereits im ungesinterten Zustand durch eine mechanische Bearbeitung von gepressten Halbzeugen erreicht wird. Diese sog. Grünbearbeitung kann ohne zusätzliche organische Binder durchgeführt werden, da die Presslinge eine ausreichende Stabilität besitzen. Das Potential der neuen Herstellungsroute konnte erfolgreich am Prototyp einer Pfanne, die für den Einsatz in der Hüftendoprothetik vorgesehen ist, aufgezeigt werden. Zusätzlich wurden einige grundlegende Untersuchungen des hochporösen Titanwerkstoffs hinsichtlich seiner Eignung als Implantatwerkstoff durchgeführt.
Health outcomes among patients receiving oseltamivir
Authors: Enger Cheryl , Nordstrom Beth L. , Thakrar Bharat , Sacks Susan , Rothman Kenneth J. 
Published: April 2004

AbstractPurposeOseltamivir was approved by the FDA for the treatment of influenza in 1999. The primary objective was to compare health outcomes among influenza patients who were treated with oseltamivir and those who were not.MethodsThe patient population included UnitedHealthcare members who received an influenza diagnosis during the 1999–2000 influenza season, divided into those who were dispensed oseltamivir on the same day (N = 3211) and those who were not dispensed oseltamivir (N = 19 985). Cardiovascular, neuropsychiatric and respiratory outcomes were assessed from medical claims for a 30‐day period.ResultsThe adjusted incidence rate ratio for major cardiac outcome was 0.56 (95%CI: 0.34–0.93) in those without a positive history of major cardiac disease, indicating that those in the oseltamivir group tended to be at lower risk of cardiac outcomes than those without oseltamivir. The adjusted incidence rate ratio for major neuropsychiatric outcome was 0.72 (95%CI: 0.53–0.97) in the negative history of neuropsychiatric disease stratum. The incidence rate ratios for respiratory events were more variable.ConclusionsThere appears to be no increased risk of cardiac or neuropsychiatric outcomes among subjects with influenza who were treated with oseltamivir in comparison with those who were not. Copyright © 2003 John Wiley & Sons, Ltd.
Enhancing capillary liquid chromatography/tandem mass spectrometry of biogenic amines by pre‐column derivatization with 7‐fluoro‐4‐nitrobenzoxadiazole
Authors: Song Yaru , Quan Zhe , Evans Joseph L. , Byrd Edward A. , Liu Yi‐Ming 
Published: April 2004

AbstractThis paper describes a capillary liquid chromatography/tandem mass spectrometry (LC/MS/MS) determination of biogenic amines enhanced by pre‐column derivatization with 7‐fluoro‐4‐nitrobenzoxadiazole (NBD‐F). Biogenic amines including tryptamine, N‐methylsalsolinol, histamine, and agmatine were studied. The biogenic NBD‐amine derivatives could be quantitatively enriched in‐line on 20 × 0.25 mm capillary columns packed in‐house with 5 μm C8 silica particles. In an electrospray ionization (ESI) source these derivatives were ionized effectively, and collision‐induced dissociation (CID) produced predominant characteristic ions allowing sensitive MS/MS detection. Agmatine, a potential neurotransmitter/modulator, was taken as a reference compound to study the analytical figures of merit of the procedure. The detection limit of agmatine was estimated to be 0.6 ng/mL (signal‐to‐noise (S/N) = 3). A linear calibration curve in the range 15–1000 ng/mL agmatine with an r value of 0.9997 was obtained. Tissue samples of rat brain, stomach, and intestine were analyzed. Minimum sample pre‐treatment was needed. Each analysis was accomplished within ca. 12 min. The concentration of agmatine was found to be 0.246, 3.31, and 0.058 μg/g wet tissue in the brain, stomach, and intestine, respectively. Copyright © 2004 John Wiley & Sons, Ltd.
Studies of Thermobifida fusca plant cell wall degrading enzymes
Authors: Wilson David B. 
Published: April 2004

AbstractSYNOPSIS: I have been studying the Thermobifida fusca cellulose degrading proteins for the past 25 years. In this period, we have purified and characterized the six extracellular cellulases and an intracellular β‐ glucosidase used by T. fusca for cellulose degradation, cloned and sequenced the structural genes encoding these enzymes, and helped to determine the 3‐dimensional structures of two of the cellulase catalytic domains. This research determined the mechanism of a novel class of cellulase, family 9 processive endoglucanases, and helped to show that there were two types of exocellulases, ones that attacked the non‐reducing ends of cellulose and ones that attacked the reducing ends. It also led to the sequencing of the T. fusca genome by the DOE Joint Genome Institute. We have studied the mechanisms that regulate T. fusca cellulases and have shown that cellobiose is the inducer and that cellulase synthesis is repressed by any good carbon source. A regulatory protein (CelR) that functions in the induction control has been purified, characterized, and its structural gene cloned and expressed in E. coli. I have also carried out research on two rumen bacteria, Prevotella ruminicola and Fibrobacter succinogenes, in collaboration with Professor James Russell, helping to arrange for the genomes of these two organisms to be sequenced by TIGR, funded by a USDA grant to the North American Consortium for Genomics of Fibrolytic Ruminal Biology. © 2004 The Japan Chemical Journal Forum and Wiley Periodicals, Inc. Chem Rec 4: 72–82; 2004: Published online in Wiley InterScience (www.interscience.wiley.com) DOI 10.1002/tcr.20002
Innovative reactions mediated by zirconocene
Authors: Fujita Kazuya , Yorimitsu Hideki , Oshima Koichiro 
Published: April 2004

AbstractRadical reactions mediated by Schwartz reagent and zirconocene(alkene) complex are firstly described. Schwartz reagent is a promising alternative to tributyltin hydride and the first transition metal hydrido complex used as a radical mediator in organic synthesis. A zirconocene(alkene) complex effects single electron transfer to alkyl halide to generate the corresponding alkyl radical. Secondly, serendipitous allylic CH bond activation of the coordinating alkene of zirconocene(alkene) complex and its application to organic synthesis are summarized. By utilizing equilibrium between zirconocene(alkene) and zirconocene 2‐alkenyl hydride, reaction of acid chloride with zirconocene(alkene) provides the corresponding homoallylic alcohol by sequential attacks of the hydride and 2‐alkenyl moieties. A set of hydride and 2‐alkenyl attacks on 1,4‐diketone yields 6‐heptene‐1,4‐diol derivative in high yield with high stereoselectivity. Selective capture of the hydride with diisopropyl ketone gives zirconocene 2‐alkenyl alkoxide, which is a useful reagent for stereoselective allylation of aldehyde and imine. α‐Halo carbonyl compounds undergo radical allylation with the zirconocene 2‐alkenyl alkoxide which serves as a substitute for allyltin. © 2004 The Japan Chemical Journal Forum and Wiley Periodicals, Inc. Chem Rec 4: 110–119; 2004: Published online in Wiley InterScience (www.interscience.wiley.com) DOI 10.1002/tcr.20004
Sonographic findings in acute urinary retention secondary to retroverted gravid uterus: pathophysiology and preventive measures
Authors: Yang J.‐M. , Huang W.‐C. 
Published: April 2004

AbstractObjectivesTo explore the pathophysiology of acute urinary retention in women with a retroverted gravid uterus and to suggest measures to prevent its recurrence.MethodsIn five women with a retroverted gravid uterus and acute urinary retention necessitating catheterization, the morphology of the genitourinary system was assessed by using transabdominal, transvaginal and introital sonography.ResultsIn the supine resting position, the cervix was displaced superiorly and anteriorly by the impacted and retroverted uterus so that it compressed the lower bladder, leading to obstruction of the internal urethral orifice. The upper bladder extended superiorly and overlay the uterus. During straining, urethral motion was not limited and there was an average rotational angle of the bladder neck of 32 °, ranging from 21 ° to 44 °. Increasing abdominal pressure further compressed the lower bladder. Measures suggested to the women for the prevention of urinary retention included limiting fluid intake before sleep, changing from the supine to the prone position before getting up and avoiding a Valsalva maneuver but performing a Credé maneuver during voiding. In all except one case these measures successfully prevented recurrence.ConclusionsAcute urinary retention secondary to a retroverted gravid uterus is caused by a displaced cervix compressing the lower bladder and interfering with drainage to the urethra. The urethra itself is not compressed or distorted. Understanding the pathophysiology of the lower urinary tract may allow maneuvers which prevent acute urinary retention. Copyright © 2004 ISUOG. Published by John Wiley & Sons, Ltd.
CVD‐Diamantschleifstifte für den Werkzeug‐ und Formenbau. Abrasive Pencils for Tool and Die Making Coated by Diamond CVD
Authors: Hoffmeister Hans‐Werner , Illenseer Stephen , Gäbler Jan 
Published: April 2004

AbstractNeuartige compeDIA®‐Diamantschleifstifte wurden hergestellt und für die Bearbeitung von Hartmetallformwerkzeugen erprobt. Zur Herstellung der Schleifstifte wurden Hartmetallgrundkörper angeschliffen und mit dem Heißdraht‐CVD‐Verfahren mit einem Diamantschleifbelag beschichtet. Die Erprobung der Schleifstifte erfolgte mit einer Ultrapräzisionsschleifmaschine an Hartmetallwerkstücken. Beurteilungskriterien waren Werkstückrauheit und Werkzeugstandzeit.Zur gezielten Einstellung der Schleifkörnung der Schleifstifte wurden die passenden Beschichtungsparameter erarbeitet und die Abhängigkeiten von wesentlichen Einflussgrößen bei der Beschichtung, wie Nenndurchmesser und Schleiflänge, ermittelt. Um die angeschliffenen Grundkörper mit ausreichender Schichthaftung beschichten zu können, wurde ein geeignetes Vorbehandlungsverfahren entwickelt und erprobt, das die durch das Anschleifen gestörte Randzone entfernt.Die Beschichtungskosten liegen jedoch momentan noch unwirtschaftlich hoch. Durch eine Massenfertigung in Verbindung mit einer automatisierten Vorbehandlung und Beschichtung wäre es möglich die Kosten soweit zu senken, dass sie auf dem Niveau anderer Beschichtungen wie TiN oder TiAlN liegen.Die CVD‐Diamantschleifstifte zeigten eine gute Eignung zur Herstellung von Formwerkzeugen für den Werkzeug‐ und Formenbau. Es ist zu erwarten, dass durch Weiterentwicklung der Werkzeuge und Prozessoptimierung die gefertigte Werkstückqualität verbessert werden kann und Rauhtiefen Ra < 0,3 μm erreicht werden. Die Standzeit konnte durch Optimierung der Beschichtungstechnologie auf anwendungsgerechte Werte gesteigert werden. Es wurden die Bearbeitungsparameterbereiche erarbeitet, mit denen die Schleifbearbeitung sinnvoll durchgeführt werden kann, ohne zum Werkzeugbruch zu führen. Anschließend wurde ein Spritzgussbauteil mit typischen Formelementen entworfen und ein entsprechender Formwerkzeugprototyp gefertigt.Für den Werkzeug‐ und Formenbau wurden damit die grundlegenden Voraussetzungen erarbeitet, mit diesen innovativen Schleifstiften eine schnelle und flexible Bearbeitung von Formwerkzeugen aus Hartmetall zu realisieren. Gegenüber dem heute üblichen Formwerkzeugmaterial aus Messing können so deutliche Standzeitvorteile bei der Herstellung von Miniatur‐Serienteilen durch Ziehen, Tiefziehen oder Fließpressen erzielt werden.
Micro‐PIXE studies of low‐level gold solubility in natural magmas: Experiments on two felsic magmas
Authors: Stevens G. , Przybyłowicz W. J. , Martin L. E. 
Published: April 2004

AbstractThe limits of gold solubility in granitic magmas are poorly constrained, yet may be important for understanding the formation of several gold deposit types. This is largely due to the fact that this parameter cannot be readily measured in natural rocks. Experimental approaches are also difficult, as an analytical technique is required that combines a high level of spatial resolution (typically <5 µm) with the capability to measure gold in low concentrations. In an attempt to address this problem, experiments were conducted to investigate gold solubility in sulphur‐ and chlorine‐bearing granitic and syenitic magmas, and the products were analysed by micro‐PIXE (particle‐induced x‐ray emission). Starting glasses were synthesized from aluminosilicate gels fired at 1000°C, and were sealed within gold capsules, with 4.4 wt% H2O and variable proportions of either chlorine or sulphur as potential gold complexing agents. The initially gold free glasses were equilibrated with the pure gold capsules at conditions of 1.5 MPa, 750°C and at fO2≈NNO buffer, for a period of at least 150 h. All experiments produced quenched granitic and syenitic glasses containing a disseminated, high‐temperature silicate mineral assemblage, in addition to oxide and/or sulphide and small gold crystals. The gold, sulphur and chlorine concentrations of the glasses were analysed, and under the specific analytical conditions used in this study micro‐PIXE was able to detect gold in the glasses at levels as low as 2 ppm. The PIXE data demonstrate that, under the conditions used in this investigation, sulphur is a more effective complexing ligand than chlorine for incorporating gold into the melt structures, and that surprisingly high gold concentrations of up to 4400 ppm were attained in the syenitic magma with 1 wt% sulphur added. Thus, micro‐PIXE analysis has been shown to be capable of constraining the concentration of gold at the generally low values encountered in solubility studies on felsic natural magma compositions, thereby laying the groundwork for future research in this field using the PIXE technique. Copyright © 2004 John Wiley & Sons, Ltd.
EPMA mapping method for small particles of Al3Fe, Al6Fe, α‐AlFeSi and β‐AlFeSi in 1050‐H18 aluminum sheets
Authors: Osada Yoshio 
Published: April 2004

AbstractWe developed an EPMA mapping method for small AlaFebSic particles in 1050‐H18 aluminum sheet, which is one of the base materials coated by photoresist in advance called PS plate (pre‐sensitized printing plate). In this method, we used the ratios of relative x‐ray intensities, IFe/IAl and IFe/ISi instead of the mass ratios, Fe/Al and Fe/Si, of the main elements which constitute the particles and tried to determine the ratios of relative x‐ray intensities using Monte Carlo calculations. Furthermore, using this developed mapping method, we performed the mapping of small AlaFebSic particles such as Al3Fe (0–3%Si as impurities), Al6Fe (0–1%Si as impurities), α‐AlFeSi(Al8.3Fe2Si) and β‐AlFeSi(Al8.9Fe2Si2) in 1050‐H18 aluminum sheets. We found that the discrimination of these particles was achieved with this mapping method. We confirmed that this method is useful for the mapping of AlaFebSic particles in 1050‐H18 aluminum sheets. Copyright © 2004 John Wiley & Sons, Ltd.
Febrigenic signaling to the brain does not involve nitric oxide
Authors: Steiner Alexandre A , Rudaya Alla Y , Ivanov Andrei I , Romanovsky Andrej A 
Published: April 2004

The involvement of peripheral nitric oxide (NO) in febrigenic signaling to the brain has been proposed because peripherally administered NO synthase (NOS) inhibitors attenuate lipopolysaccharide (LPS)‐induced fever in rodents. However, how the unstable molecule of NO can reach the brain to trigger fever is unclear. It is also unclear whether NOS inhibitors attenuate fever by blocking febrigenic signaling or, alternatively, by suppressing thermogenesis in brown fat.
Male Wistar rats were chronically implanted with jugular catheters; their colonic and tail skin temperatures (Tc and Tsk) were monitored.
Study 1 was designed to determine whether the relatively stable, physiologically relevant forms of NO, that is, S‐nitrosoalbumin (SNA) and S‐nitrosoglutathione (SNG), are pyrogenic and whether they enhance LPS fever. At a neutral ambient temperature (Ta) of 31°C, afebrile or LPS (1 μg kg−1, i.v.)‐treated rats were infused i.v. with SNA (0.34 or 4.1 μmol kg−1; the controls received NaNO2 and albumin) or SNG (10 or 60 μmol kg−1; the controls received glutathione). Tc of SNA‐ or SNG‐treated rats never exceeded that of the controls.
In Study 2, we tested whether the known fever‐attenuating effect of the NOS inhibitor N‐nitro‐L‐arginine methyl ester (L‐NAME) at a subneutral Ta (when fever is brought about by thermogenesis) also occurs at a neutral Ta (when fever is brought about by skin vasoconstriction). At a subneutral Ta of 24°C, L‐NAME (2.5 mg kg−1, i.v.) attenuated LPS (10 μg kg−1, i.v.) fever, presumably by inhibiting thermogenesis. At 31°C, L‐NAME enhanced LPS fever by augmenting skin vasoconstriction (Tsk fall).
In summary, both SNA and SNG had no pyrogenic effect of their own and failed to enhance LPS fever; peripheral L‐NAME attenuated only fever brought about by increased thermogenesis. It is concluded that NO is uninvolved in febrigenic signaling to the brain.

British Journal of Pharmacology (2004) 141, 1204–1213. doi:10.1038/sj.bjp.0705713