bluuebunny/crossref_metadata_2025 huggingface dataset:
Studies on the composition and properties of metal ferrocyanogen complexes. II. Physico‐chemical studies on the Nature and Composition of Chromous Ferrocyanide
Authors: Malik Wahid U. , Abubacker K. M.
Published: January 2005

Potentiometric, conductometric and amperometric titrations have been carried out between CrCl2 and K4Fe(CN)6 with varying concentrations of the reagents in aqueous and aqeous‐alcoholic media. While evidence for the formation of both K2CrFe(CN)6 and Cr2Fe(CN)6 was obtained from the first two methods, the amperometric titrations gave evidence only for the formation of K2CrFe(CN)6. From the discrepancies in the titre values (theoretical and determined), evidence for the role of adsorption in influencing the composition is obtained. The titre values approach the theoretical when measurements are done in presence of alcohol.
Borinhydrazin und seine Pyrolyseprodukte
Authors: Goubeau J. , Ricker E.
Published: January 2005

Durch Umsetzung von Hydrazinsulfat mit Natriumboranat wird das Monoborinhydrazin in guten Ausbeuten erhalten, Fp. 61°. Löslichkeiten, Dipolmoment, Kristallstruktur und IR‐Spektren wurden untersucht. Bei der Pyrolyse wird rasch ein Mol Wasserstoff und ein Teil des Hydrazins abgeben. Aus den Reaktionsprodukten läßt sich unter bestimmten Versuchsbedingungen mit guten Ausbeuten H2BNHNHBH2 isolieren, das als Polymeres vorliegt und gegenüber Wasser und auch Säuren unempfindlich ist. Auch diese Verbindung ist kristallin und wurde durch ihr Debyeogramm und ihr IR‐Spektrum charakterisiert. Die weitere Pyrolyse führt zu wenig beständigen, teilweise explosiven Verbindungen der ungefähren Zusammensetzung (HBN)n, in der auch noch die NN‐Bindung des Hydrazins zum größten Teil erhalten ist.
Paramagnetische Elektronenresonanzspektren der höheren Vanadinoxide
Authors: Arija Ss. M. , Akopjan S. Ch. , Wintruff W.
Published: January 2005

Mit Hilfe der paramagnetischen Elektronenresonanz wurden die höheren Vanadinoxide VO1,5‐VO2,5 untersucht. Resonanzespektren wurden bei 300°K nur bei den Oxiden VO>2,0 und bei 77°K bei den Oxiden VO>1,7 beobachtet. Der Wert des g‐Faktors schwankt von 1,900–1,960. Eine Hyperfeinstruktur wurde nur bei den Oxiden beobachtet, die die VO2− Phase enthalten. Es wird die Frage der Wertigkeit des Vanadins in den Oxiden VO1,5‐VO2,5 auf der Grundlage der Ergebnisse der Spektren diskutiert.
Ultrasound‐guided closed drainage for abscesses of the head and neck
Authors: Chang Kai‐Ping , Chen Yao‐Liang , Hao Sheng‐Po , Chen Shih‐Ming
Published: January 2005

OBJECTIVES

To evaluate the efficacy of ultrasound‐guided percutaneous closed drainage in the management of abscesses in the head and neck.

STUDY DESIGN

Prospective, controlled study.

METHODS

From January 1998 to December 1999, patients presenting with a unilocular abscess in the head and neck and who subsequently underwent echo‐guided percutaneous drainage were enrolled in the study.

RESULTS

Fourteen patients were enrolled in the study. No patients needed open surgical drainage afterward. By our protocol, only 8 patients had an indwelling catheter. After treatment, all patients were cured of their disease completely without any complication.

CONCLUSIONS

Ultrasound‐guided percutaneous closed drainage is a safe and effective procedure and might be most beneficial in well‐defined and/or unilocular abscess in the head and neck. Closed drainage could be tried initially in an abscess of the deeper visceral spaces and will not impede any subsequent intervention by surgery. Hospital stay can be shortened and potential surgical complications may be avoided by using this procedure.
Definitive management of severe facial trauma utilizing free tissue transfer
Authors: Futran Neal D. , Farwell D. Gregory , Smith Russell B. , Johnson Paul E. , Funk Gerry F.
Published: January 2005

OBJECTIVE

Severe ballistic or avulsion injuries to the face create complex, composite defects. We report the results of an aggressive management algorithm to optimize facial form and function: (1) the initial encounter, (2) definitive reconstruction with vascularized tissue, and (3) aesthetic and prosthetic refinement.

STUDY DESIGN AND SETTING

Retrospective case series of 49 patients in 2 tertiary care institutions. Patients were evaluated for age, gender, mechanism of injury, anatomic subsites involved, surgical procedures, flaps utilized, complications, and functional outcomes.

RESULTS

Forty defects were gunshot wounds, 9 resulted from major avulsive trauma. Involved sites included 13 oromandibular, 21 midface/upper face, and 15 combined sites; 54 free flaps were utilized, 21 were soft tissue and 33 contained bone. No flap failures occurred. Function and cosmesis were best in the oromandibular only group, and worst in the combined group with nasal and/or orbital tissue loss.

CONCLUSION

Treatment of severe facial trauma requires early tissue debridement with bony repair and/or stenting to minimize scar contracture. Free tissue transfer techniques allow simultaneous reconstruction of the bony framework and overlying tissues. Multiple secondary procedures are frequently required for optimal aesthetic restoration. EBM rating: C.
Can electromagnetic fields emitted by mobile phones stimulate the vestibular organ?
Authors: Pau Hans Wilhelm , Sievert UWE , Eggert Siegfried , Wild Walter
Published: January 2005

OBJECTIVES

Pulsating electromagnetic (EM) radiation emitted by mobile phones is often incriminated for causing tissue alterations by caloric effects. In particular, the eye and the ear were regarded as possible “hot spots,” with heating up to 1°C, in which EM radiation might have negative effects. If so, these temperature increments should be large enough to cause vestibular excitation. In this study, we attempted to verify this theory by clinical testing and in vitro experiments.

METHODS AND MEASURES

In our laboratory, a simulated GSM signal (889.6 MHz/2.2 W) was applied to 1 ear at a time, while video nystagmography was performed. The experimental setup was similar to that used for caloric (hot and cold water) testing of the peripheral vestibular organ. Data were evaluated by a computer system. There were 13 volunteers (26 ears) included in our study. In an additional experiment, temperatures of human temporal bones were measured by thermography, while a continuous or pulsating EM field was applied.

RESULTS

In no volunteer could EM radiation‐induced nystagmus be recorded. This corresponds well to our findings that in the human temporal bone very weak caloric effects could only be found in the tissue layers next to the radiation source (antenna of the mobile phone), whereas deeper regions (horizontal semicircular canal) seemed unaffected (at least less than 0.1°C).

CLINICAL SIGNIFICANCE

These results do not support the theory that mobile phone‐induced EM radiation may cause caloric negative effects in the human ear.
Volumetric tissue reduction in radiofrequency surgery of the tongue base
Authors: Stuck Boris A. , Köpke Julian , Hörmann Karl , Verse Thomas , Eckert Andreas , Bran Gregor , Dübre Christoph , Maurer Joachim T.
Published: January 2005

OBJECTIVES

Radiofrequency surgery is a minimally invasive technique for the treatment of the tongue base in sleep‐disordered breathing. The aim of this study was to evaluate the changes in upper airway anatomy induced by radiofrequency surgery with MRI.

STUDY DESIGN AND SETTING

10 patients with sleep‐disordered breathing were treated with radiofrequency surgery at tongue base. MRI measurements were performed before and after surgery with the help of a recently published protocol.

RESULTS

The mean total number of energy delivered per patient was 4750 ± 1641 Joule. Relevant changes could be observed neither for tongue volume or dimension nor for retrolingual space.

CONCLUSIONS

Changes in upper airway anatomy could not be demonstrated. The effects of radiofrequency surgery of the tongue base may more likely be a result of changes in upper airway collapsibility.

SIGNIFICANCE

Functional effects of surgical interventions in sleep‐disordered breathing should be considered in addition to mechanistic concepts alone.
The effect of silence on tinnitus perception
Authors: Tucker Denise A. , Phillips Susan L. , Ruth Roger A. , Clayton Windy A. , Royster Eden , Todd Allison D.
Published: January 2005

OBJECTIVE

The effect of sustained silence was studied on the emergence of tinnitus perception in 120 normal hearing young adult Caucasians and African Americans.

STUDY DESIGN AND SETTING

After sitting in a sound booth for a period of 20 minutes, participants were asked to complete a questionnaire documenting whether they perceived sounds in the silent setting and descriptions of the sounds they heard.

RESULTS

Tinnitus‐like sounds were perceived in 64% of listeners overall. No significant differences in tinnitus perception were observed between males and females. However, there was a significant difference in tinnitus perception between Caucasian and African American subjects, with tinnitus sounds emerging in sustained silence less frequently in African American listeners. Tinnitus emerged quickly in a majority of subjects (less than 4 minutes) and African American subjects who perceived tinnitus heard a greater number of individual tinnitus‐like sounds than did Caucasian subjects. Ring (57%), buzz (21%), pulse (22%), heartbeat (21%), and hum (14%) were the most common sounds heard, with ring being the most common overall tinnitus perception.

CONCLUSIONS AND SIGNIFICANCE

Few investigators have documented at the emergence of tinnitus in normal hearing subjects. Results of the current study found significant differences in tinnitus perception between Caucasian and African American subjects, but found no significant differences when comparing males and female subjects. EBM rating: C.
New Order and Good Government: Municipal Administration in Belgium, 1938–1946
Authors: WOUTERS NICO
Published: January 2005

The inefficient operation of state institutions – including municipal administration – lay at the heart of Belgium's crisis of legitimacy in the 1930s. In 1940, the German military occupation government opted to keep many of the existing administrative institutions and personnel in place. The collaborating political parties, Rex and the Vlaams Nationaal Verbond (VNV), possessed little legitimacy with either the Germans or the Belgian population. However, this article argues that both parties turned this to their advantage, infiltrating the Flemish municipal apparatus (especially mayors). Yet, as their political programme and legitimation was completely derived from the Germans, their legal position as administrators (especially mayors) was very weak. Both collaborating parties compensated for this with the theory of ‘good government’. Their takeover of power was an administrative operation which, the article argues, would bring them legitimacy through everyday ‘good government’. The entire ‘Neuordnung’ in Belgium in 1940–2 was strongly legitimised on administrative, not political grounds. The failure of this tactic lay in the open politicisation of collaborationist local government. As the article shows, the post-liberation authority also faced a problem of legitimacy. Generally speaking, the trauma of occupation had seemed to strengthen Belgians' wishes for the restoration of stability rather than reforms.
Legitimacy/Legitimation/Delegitimation: France in the Dark Years, a Textbook Case
Authors: PESCHANSKI DENIS
Published: January 2005

The history of France's defeat, occupation and subsequent liberation may be read, and written, as a constant struggle for legitimacy. Here the diverse candidates for legitimacy are analysed (Pétain, de Gaulle and the internal Resistance) as well as the agents of legitimation, and the arbiters of that process of legitimation (French society, the German occupier, Britain and the United States). Four successive configurations are distinguished within that struggle for legitimacy: summer 1940 to spring 1941, the time of the defeat; summer and autumn 1941, when French society called into question the legitimacy of the Vichy French State; the crossroads of greatest legitimacy between late 1942 and mid-1943, which also marked the period of greatest fragility for de Gaulle; and spring to autumn 1944, when the key question was which state should be rebuilt.
The Landscape of Sound in the Nineteenth and Twentieth Centuries
Authors: TOURNÈS LUDOVIC
Published: January 2005

Alain Corbin, Les cloches de la terre. Paysage sonore et culture sensible dans les campagnes au XIXe siècle (Paris: Flammarion, 1994), 359 pp., €8.69 (pb), ISBN 2080814532.

Glenn Watkins, Proof through the Night. Music and the Great War (Berkeley, Los Angeles and London: University of California Press, 2003), 598 pp., $49.95 (hb), ISBN 0520231589.

Jeffrey Jackson, Making Jazz French. Music and Modern Life in Interwar Paris (Durham, NC, and London: Duke University Press, 2003), 266 pp., $21.95 (pb), ISBN 0822331373.

Bernard Gendron, Between Montmartre and the Mudd Club. Popular Music and the Avant-Garde (Chicago and London: University of Chicago Press, 2003), 388 pp., $55.00 (hb), ISBN 0226287351.

David Looseley, Popular Music in Contemporary France (Oxford and New York: Berg, 2003), 254 pp., $25.00 (pb), ISBN 1859736319.

Though undoubtedly thriving, the history of music is still a somewhat peripheral area of research which many historians dismiss as secondary. For many years publication in the subject remained the domain of two kinds of researchers, either musicologists – ‘insiders’ au fait with the technical vocabulary – or sociologists and practitioners of ‘cultural studies’ – ‘outsiders’ chiefly interested in the reception of musical phenomena and their role in the constitution of individual and collective identities. This division has become very blurred over the last few years, which have seen the emergence of a number of works with an interdisciplinary approach. But for most historians the history of music remains a largely unfamiliar theme which they struggle to include in any global social or cultural analysis. This struggle is apparent at two levels: first, the difficulty of developing guidelines to the historicity of musical events and, second, the difficulty of escaping the chronology of classical music, which is predicated on a succession of styles and composers. Based on these two points, this article will attempt to develop, through a transverse reading of certain recent works, some working hypotheses centring on the notion of a ‘landscape of sound’ or paysage sonore, as proposed some ten years ago by Alain Corbin, a notion which, it seems to me, may make a valuable contribution to rejuvenating the history of music.
Exploring changes in river nitrogen export to the world's oceans
Authors: Bouwman A. F. , Van Drecht G. , Knoop J. M. , Beusen A. H. W. , Meinardi C. R.
Published: January 2005

Anthropogenic disturbance of river nutrient loads and export to coastal marine systems is a major global problem affecting water quality and biodiversity. Nitrogen is the major nutrient in rivers. On the basis of projections for food production and wastewater effluents, the global river N flux to coastal marine systems is shown to increase by 13% in the coming 3 decades. While the river N flux will grow by about 10% in North America and Oceania and will decrease in Europe, a 27% increase is projected for developing countries, which is a continuation of the trend observed in the past decades. This is a consequence of increasing nitrogen inputs to surface water associated with urbanization, sanitation, development of sewerage systems, and lagging wastewater treatment, as well as increasing food production and associated inputs of N fertilizer, animal manure, atmospheric N deposition, and biological N fixation in agricultural systems. Growing river N loads will lead to increased incidence of problems associated with eutrophication in coastal seas.
Sediments of salt lakes as a new source of volatile highly chlorinated C1/C2 hydrocarbons
Authors: Weissflog L. , Lange C. A. , Pfennigsdorff A. , Kotte K. , Elansky N. , Lisitzyna L. , Putz E. , Krueger G.
Published: January 2005

It is shown for the first time that the volatile highly chlorinated C2 hydrocarbons (VCHCs) trichloroethene (TRI; C2HCl3), tetrachloroethene (PER; C2Cl4) and methyl chloroform (MC; C2H3Cl3), but also C1 hydrocarbons tetrachloromethane and chloroform can be naturally formed in the sediment of salt lakes (ssl). Archaic halobacteria appear to play a key role in the microbial formation involved. TRI, PER and MC can be transformed into trichloroacetic acid (TCA) in the atmosphere. TRI and PER can also be metabolised into TCA following uptake by plants. Already considerably phytotoxic by itself, TCA's phytotoxicity is exacerbated if the vegetation concerned is simultaneously exposed to drought‐stress. TRI and PER, emitted by these newly identified natural sources, can accelerate desertification in semi‐arid and arid climate zones in consequence of the destabilisation of vegetation by its phytotoxic metabolite TCA.
Plasmoid in the high latitude boundary/cusp region observed by Cluster
Authors: Zong Q.‐G. , Fritz T. A. , Spence H. , Zhang H. , Huang Z. Y. , Pu Z. Y. , Glassmeier K.‐H. , Korth A. , Daly P. W. , Balogh A. , Reme H.
Published: January 2005

A plasmoid‐like structure without a core magnetic field has been observed by Cluster spacecraft in the high latitude magnetopause region when the interplanetary magnetic field (IMF) is northward and has a dominant duskward component. Bursty electrons and ions are found to be well confined in this plasmoid‐like structure. The structure possesses a bipolar signature in the BN component. The structure is associated with a dramatic change of the plasma flow direction from tailward to dawnward. The plasma density in this structure is slightly enhanced whereas the ion temperature is twice as large as that of the ambient plasma. The plasma parallel temperature is higher than the perpendicular one. The observed structure is different from the traditional Flux Transfer Events (FTEs). The Walén test shows that change of plasma flow velocity are closely associated with change of Alfven velocity which indicates this structure is formed by reconnection process. The observed plasmoid is suggested to be formed by multiple X‐line reconnection in the dusk (dawn) side of the stagnant cusp region when the IMF is northward and possesses a dominant positive (negative) BY component.
Metronomic low‐dose chemotherapy as antiangiogenic therapeutic strategy for cancer
Authors: Gille Jens , Spieth Konstanze , Kaufmann Roland
Published: January 2005

New blood vessel formation is essential for the growth and metastasis of many cancers. As a result, antitumor activities of various angiogenesis inhibitors have been intensely explored in various tumors. Recent preclinical studies suggest that certain conventional cytotoxic agents can function as antiangiogenic drugs when administered at comparatively low doses on a continuous or very frequent schedule. Such antiangiogenic ‘metronomic’ scheduling of chemotherapy without extended rest periods has been shown to exert significant therapeutic antitumor efficacy with very limited toxicity in different tumor models. Combining metronomic low‐dose chemotherapy regimens with specific angiogenesis inhibitors further increases efficacy. Based on the promising preclinical studies, it is anticipated that metronomic chemotherapy in combination with angiogenesis inhibitors will prove effective in clinical trials in terms of survival prolongation. While considerable progress may derive from larger randomized clinical studies, only joint efforts between basic and clinical research will ultimately advance the new paradigm of long‐term metronomic antiangiogenic chemotherapy, which carries the prospect of turning cancer into a more controllable chronic disease at minimal toxicity.
Skin diseases described in Japan 2004
Authors: Teraki Yuichi , Nishikawa Takeji
Published: January 2005

During the last century of modern dermatology, more than 30 skin diseases have been described first by physicians from Japan. Many of those conditions were disorders of pigmentation and keratinization, which are quite common in Oriental patients. Since the late 1940s, a number of skin diseases first reported in Japan have gained attention internationally among them being Kimura disease, hypomelanosis of Ito, Kawasaki disease, adult T‐cell leukemia/lymphoma, eosinophilic pustular folliculitis, prurigo pigmentosa, and Ofuji's papuloerythroderma. In this article, we review skin diseases that were first established as distinct entities in Japan, in order to familiarize readers of the Western literature with these conditions.
EMPACT syndrome
Authors: Wöhrl Stefan , Loewe Robert , Pickl Winfried F. , Stingl Georg , Wagner Stephan N.
Published: January 2005

Background: Seizure prophylaxis with phenytoin is a common measure in oncologic patients with brain metastases. In these patients, generalized severe adverse drug reactions such as erythema multiforme (EEM) may occur. However, in a subgroup of patients with brain radiation therapy, EEM‐like lesions develop particularly in the radiation field. Most recently, the acronym EMPACT (Erythema Multiforme associated with Phenytoin And Cranial radiation Therapy) was proposed to specifically describe this syndrome.

Patient/Method: Here, we report on EMPACT syndrome in a 46‐year‐old woman. Therapeutic measures included seizure prophylaxis with phenytoin and total brain radiation therapy of brain metastases from bronchial carcinoma. Three weeks after introduction of phenytoin, the patient presented with EEM‐like skin lesions restricted to the original radiation field and facial mucocutaneous involvement. After a few days, the rash spread to the upper part of the body. She was also in poor general condition.

Results: The immediate cessation of phenytoin therapy, combined with administration of systemic corticosteroids and high dose immunoglobulins along with intensive local treatment and pain medications, resulted in complete resolution of the skin eruption. Patch testing to phenytoin was positive after 72 hours.

Conclusion: EMPACT should be classified as an specific entity among the EEM‐like drug reactions as it only appears after radiotherapy and seizure prophylaxis with the anticonvulsant phenytoin. We propose including specific type IV‐sensitization to phenytoin into the definition of EMPACT.
Dynamical models of weak scattering
Authors: Field Timothy R. , Tough Robert J. A.
Published: January 2005

We extend a recent diffusion model, in which the continuous time dynamics of the K-scattering process have been proposed, to include the effect of the presence of a coherent offset in the scattering amplitude. The weak scattering amplitudes are characterized in terms of continuous time biased random walk models, and the corresponding stochastic dynamics derived. The stochastic differential geometry of the resultant amplitude fluctuations is derived in relation to that of pure K-scattering. Asymptotic distributions of amplitude, intensity, and phase are provided, and the condition for detailed balance shown to hold.
Wigner–Weyl isomorphism for quantum mechanics on Lie groups
Authors: Mukunda N. , Marmo G. , Zampini A. , Chaturvedi S. , Simon R.
Published: January 2005

The Wigner–Weyl isomorphism for quantum mechanics on a compact simple Lie group G is developed in detail. Several features are shown to arise which have no counterparts in the familiar Cartesian case. Notable among these is the notion of a semiquantized phase space, a structure on which the Weyl symbols of operators turn out to be naturally defined and, figuratively speaking, located midway between the classical phase space T*G and the Hilbert space of square integrable functions on G. General expressions for the star product for Weyl symbols are presented and explicitly worked out for the angle-angular momentum case.
Critical behavior of the compactified λϕ4 theory
Authors: Abreu L. M. , de Calan C. , Malbouisson A. P. C. , Malbouisson J. M. C. , Santana A. E.
Published: January 2005

We investigate the critical behavior of the N-component Euclidean λϕ4 model, in the large N limit, in three situations: confined between two parallel planes a distance L apart from one another; confined to an infinitely long cylinder having a square transversal section of area L2; and to a cubic box of volume L3. Taking the mass term in the form m02=α(T−T0), we retrieve Ginzburg–Landau models which are supposed to describe samples of a material undergoing a phase transition, respectively, in the form of a film, a wire and of a grain, whose bulk transition temperature (T0) is known. We obtain equations for the critical temperature as functions of L and of T0, and determine the limiting sizes sustaining the transition.
A model for Hopfions on the space–time S3×R
Authors: De Carli E. , Ferreira L. A.
Published: January 2005

We construct static and time dependent exact soliton solutions for a theory of scalar fields taking values on a wide class of two dimensional target spaces, and defined on the four dimensional space–time S3×R. The construction is based on an ansatz built out of special coordinates on S3. The requirement for finite energy introduce boundary conditions that determine an infinite discrete spectrum of frequencies for the oscillating solutions. For the case where the target space is the sphere S2, we obtain static soliton solutions with nontrivial Hopf topological charges. In addition, such Hopfions can oscillate in time, preserving their topological Hopf charge, with any of the frequencies belonging to that infinite discrete spectrum.
Stability of vacuum-ultraviolet radiometric transfer standards: Electron cyclotron resonance versus hollow cathode source
Authors: Gottwald Alexander , Richter Mathias , Ulm Gerhard , Schühle Udo
Published: January 2005

Established transfer standards such as Penning and hollow cathode discharge sources suffer from limited spectral range and, in particular, a limited lifetime and stability due to electrode erosion. The development of a vacuum-ultraviolet radiation source based on an electron cyclotron resonance (ECR)-created plasma might overcome these limitations. To test such a source with regard to its usefulness as radiometric transfer standard, the emission intensity of a Ne plasma was monitored over an operation period of 180 days, with regard to stability and reproducibility in the 50–75 nm wavelength range. For comparison and calibration, a hollow cathode was used as transfer standard traceable to the electron storage ring BESSY II as primary standard. It was found that the ECR source exceeded the lifetime of the hollow cathode source by far, offering a more balanced spectral emission line variety with similar stability.
Free electron laser-Fourier transform ion cyclotron resonance mass spectrometry facility for obtaining infrared multiphoton dissociation spectra of gaseous ions
Authors: Valle Jose J. , Eyler John R. , Oomens Jos , Moore David T. , van der Meer A. F. G. , von Helden Gert , Meijer Gerard , Hendrickson Christopher L. , Marshall Alan G. , Blakney Gregory T.
Published: January 2005

A Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometer has been installed at a free electron laser (FEL) facility to obtain infrared absorption spectra of gas phase ions by infrared multiple photon dissociation (IRMPD). The FEL provides continuously tunable infrared radiation over a broad range of the infrared spectrum, and the FT-ICR mass spectrometer, utilizing a 4.7Tesla superconducting magnet, permits facile formation, isolation, trapping, and high-mass resolution detection of a wide range of ion classes. A description of the instrumentation and experimental parameters for these experiments is presented along with preliminary IRMPD spectra of the singly-charged chromium-bound dimer of diethyl ether (Cr(C4H10O)2+) and the fluorene molecular ion (C13H10+). Also presented is a brief comparison of the fluorene cation spectrum obtained by the FT-ICR-FEL with an earlier spectrum recorded using a quadrupole ion trap (QIT).
The scaling properties of dissipation in incompressible isotropic three-dimensional magnetohydrodynamic turbulence
Authors: Merrifield J. A. , Müller W.-C. , Chapman S. C. , Dendy R. O.
Published: January 2005

The statistical properties of the dissipation process constrain the analysis of large scale numerical simulations of three-dimensional incompressible magnetohydrodynamic (MHD) turbulence, such as those of Biskamp and Müller [Phys. Plasmas 7, 4889 (2000)]. The structure functions of the turbulent flow are expected to display statistical self-similarity, but the relatively low Reynolds numbers attainable by direct numerical simulation, combined with the finite size of the system, make this difficult to measure directly. However, it is known that extended self-similarity, which constrains the ratio of scaling exponents of structure functions of different orders, is well satisfied. This implies the extension of physical scaling arguments beyond the inertial range into the dissipation range. The present work focuses on the scaling properties of the dissipation process itself. This provides an important consistency check in that we find that the ratio of dissipation structure function exponents is that predicted by the She and Leveque [Phys. Rev. Lett 72, 336 (1994)] theory proposed by Biskamp and Müller. This supplies further evidence that the cascade mechanism in three-dimensional MHD turbulence is nonlinear random eddy scrambling, with the level of intermittency determined by dissipation through the formation of current sheets.
Piezo-, pyro-, ferro-, and dielectric properties of ceramic/polymer composites obtained from two modifications of lead titanate
Authors: Peláiz-Barranco A. , Marin-Franch P.
Published: January 2005

Two modifications of lead titanate ceramic and the polyetherketoneketone polymer (PEKK) have been used to obtain two polymer/ceramic composites. The piezo-, pyro-, ferroelectric, and dielectric properties were studied. The calcium modified lead titanate/polyetherketoneketone (PTCa/PEKK) composite shows better piezo- and pyro-electric properties than that of the samarium and manganese modified lead titanate/polyetherketoneketone (PSTM/PEKK) composite. Also, a lower dielectric permittivity and remanent polarization values with a higher coercive field are obtained. The results are discussed considering the modifications made in the ceramic phases of each composite. The presented properties for both composites are still substantially lower than those in bulk ceramics.
Theoretical study of electrolyte gate AlGaN∕GaN field effect transistors
Authors: Bayer M. , Uhl C. , Vogl P.
Published: January 2005

We predict the sensitivity of solution gate AlGaN∕GaN field effect transistors to pH values of the electrolyte and to charged adsorbates at the semiconductor–electrolyte interface. Invoking the site-binding model for the chemical reactions at the oxidic semiconductor–electrolyte interface and taking into account the large polarization fields within the nitride heterostructure, the spatial charge and potential distribution have been calculated self-consistently both in the semiconductor and the electrolyte. In addition, the source–drain current is calculated and its sensitivity to the electrolyte’s pH value is studied systematically. Comparison with experiment shows good agreement. A significantly enhanced resolution is predicted for AlGaN∕GaN structures of N-face polarity.
Ethanol-withdrawal seizures are controlled by tissue plasminogen activator via modulation of NR2B-containing NMDA receptors
Authors: Pawlak Robert , Melchor Jerry P. , Matys Tomasz , Skrzypiec Anna E. , Strickland Sidney
Published: January 2005

Chronic ethanol abuse causes up-regulation of NMDA receptors, which underlies seizures and brain damage upon ethanol withdrawal (EW). Here we show that tissue-plasminogen activator (tPA), a protease implicated in neuronal plasticity and seizures, is induced in the limbic system by chronic ethanol consumption, temporally coinciding with up-regulation of NMDA receptors. tPA interacts with NR2B-containing NMDA receptors and is required for up-regulation of the NR2B subunit in response to ethanol. As a consequence, tPA-deficient mice have reduced NR2B, extracellular signal-regulated kinase 1/2 phosphorylation, and seizures after EW. tPA-mediated facilitation of EW seizures is abolished by NR2B-specific NMDA antagonist ifenprodil. These results indicate that tPA mediates the development of physical dependence on ethanol by regulating NR2B-containing NMDA receptors.
Partial
d
-amino acid substitution: Improved enzymatic stability and preserved Ab recognition of a MUC2 epitope peptide
Authors: Tugyi Regina , Uray Katalin , Iván Dóra , Fellinger Erzsébet , Perkins Alan , Hudecz Ferenc
Published: January 2005

The stability of an immunogen against enzymatic degradation is considered an important factor for the design of synthetic vaccines. For our studies, we have selected an epitope from the tandem-repeat unit of the high-molecular-weight MUC2 mucin glycoprotein, which can be underglycosylated in case of colon cancer. In this study, we prepared a MUC2 peptide containing the PTGTQ epitope of a MUC2 protein backbone-specific mAb 996 and its derivatives. In these peptides, the N- and C-terminal flanking regions were systematically substituted by up to three
d
-amino acids. Peptides prepared by solid-phase synthesis were tested for their mAb 996 binding in competitive ELISA experiments, and their stability was studied in serum and lysosomal preparation. Our data show that the epitope function of peptide
15
TPT
PTGTQ
TPT
25
is retained even in the presence of two
d
-amino acid residues at its N-terminal flanking region and up to three at its C-terminal flanking region (tpTPTGTQtpt). Also, this partly
d
peptide shows high resistance against proteolytic degradation in diluted human serum and in lysosomal preparation. These findings suggest that, by appropriate combination of structural modifications (namely,
d
-amino acid substitution) in the flanks of an Ab epitope, it is feasible to construct a synthetic antigen with preserved recognition properties and high stability against enzymatic degradation. Peptides tPTPTGTQTpt and tpTPTGTQTpt derived from this study can be used for immunization experiments and as potential components of synthetic vaccines for tumor therapy.
Changes in extracellular space size and geometry in APP23 transgenic mice: A model of Alzheimer's disease
Authors: Syková Eva , Voříšek Ivan , Antonova Tatiana , Mazel Tomáš , Meyer-Luehmann Melanie , Jucker Mathias , Hájek Milan , Or Michael , Bureš Jan
Published: January 2005

Diffusion parameters of the extracellular space (ECS) are changed in many brain pathologies, disturbing synaptic as well as extrasynaptic “volume” transmission, which is based on the diffusion of neuroactive substances in the ECS. Amyloid deposition, neuronal loss, and disturbed synaptic transmission are considered to be the main causes of Alzheimer's disease dementia. We studied diffusion parameters in the cerebral cortex of transgenic APP23 mice, which develop a pathology similar to Alzheimer's disease. The real-time tetramethylammonium (TMA) method and diffusion-weighted MRI were used to measure the ECS volume fraction (α = ECS volume/total tissue volume) and the apparent diffusion coefficients (ADCs) of TMA (ADC
TMA
), diffusing exclusively in the ECS and of water (ADC
W
). Measurements were performed
in vivo
in 6-, 8-, and 17- to 25-month-old hemizygous APP23 male and female mice and age-matched controls. In all 6- to 8-month-old APP23 mice, the mean ECS volume fraction, ADC
TMA
, and ADC
W
were not significantly different from age-matched controls (α = 0.20 ± 0.01; ADC
TMA
, 580 ± 16 μm
2
·s
-1
; ADC
W
, 618 ± 19 μm
2
·s
-1
). Aging in 17- to 25-month-old controls was accompanied by a decrease in ECS volume fraction and ADC
W
, significantly greater in females than in males, but no changes in ADC
TMA
. ECS volume fraction increased (0.22 ± 0.01) and ADC
TMA
decreased (560 ± 7 μm
2
·s
-1
) in aged APP23 mice. The impaired navigation observed in these animals in the Morris water maze correlated with their plaque load, which was twice as high in females (20%) as in males (10%) and may, together with changed ECS diffusion properties, account for the impaired extrasynaptic transmission and spatial cognition observed in old transgenic females.
Evidence for self-cleaning in gecko setae
Authors: Hansen W. R. , Autumn K.
Published: January 2005

A tokay gecko can cling to virtually any surface and support its body mass with a single toe by using the millions of keratinous setae on its toe pads. Each seta branches into hundreds of 200-nm spatulae that make intimate contact with a variety of surface profiles. We showed previously that the combined surface area of billions of spatulae maximizes van der Waals interactions to generate large adhesive and shear forces. Geckos are not known to groom their feet yet retain their stickiness for months between molts. How geckos manage to keep their feet clean while walking about with sticky toes has remained a puzzle until now. Although self-cleaning by water droplets occurs in plant and animal surfaces, no adhesive has been shown to self-clean. In the present study, we demonstrate that gecko setae are a self-cleaning adhesive. Geckos with dirty feet recovered their ability to cling to vertical surfaces after only a few steps. Self-cleaning occurred in arrays of setae isolated from the gecko. Contact mechanical models suggest that self-cleaning occurs by an energetic disequilibrium between the adhesive forces attracting a dirt particle to the substrate and those attracting the same particle to one or more spatulae. We propose that the property of self-cleaning is intrinsic to the setal nanostructure and therefore should be replicable in synthetic adhesive materials in the future.
The PSD95–nNOS interface
Authors: Cao Jiong , Viholainen Jenni I. , Dart Caroline , Warwick Helen K. , Leyland Mark L. , Courtney Michael J.
Published: January 2005

The stress-activated protein kinase p38 and nitric oxide (NO) are proposed downstream effectors of excitotoxic cell death. Although the postsynaptic density protein PSD95 can recruit the calcium-dependent neuronal NO synthase (nNOS) to the mouth of the calcium-permeable NMDA receptor, and depletion of PSD95 inhibits excitotoxicity, the possibility that selective uncoupling of nNOS from PSD95 might be neuroprotective is unexplored. The relationship between excitotoxic stress–generated NO and activation of p38, and the significance of the PSD95–nNOS interaction to p38 activation also remain unclear. We find that NOS inhibitors reduce both glutamate-induced p38 activation and the resulting neuronal death, whereas NO donor has effects consistent with NO as an upstream regulator of p38 in glutamate-induced cell death. Experiments using a panel of decoy constructs targeting the PSD95–nNOS interaction suggest that this interaction and subsequent NO production are critical for glutamate-induced p38 activation and the ensuing cell death, and demonstrate that the PSD95–nNOS interface provides a genuine possibility for design of neuroprotective drugs with increased selectivity.
Identification of cytoplasmic residues of Sec61p involved in ribosome binding and cotranslational translocation
Authors: Cheng Zhiliang , Jiang Ying , Mandon Elisabet C. , Gilmore Reid
Published: January 2005

The cytoplasmic surface of Sec61p is the binding site for the ribosome and has been proposed to interact with the signal recognition particle receptor during targeting of the ribosome nascent chain complex to the translocation channel. Point mutations in cytoplasmic loops six (L6) and eight (L8) of yeast Sec61p cause reductions in growth rates and defects in the translocation of nascent polypeptides that use the cotranslational translocation pathway. Sec61 heterotrimers isolated from the L8 sec61 mutants have a greatly reduced affinity for 80S ribosomes. Cytoplasmic accumulation of protein precursors demonstrates that the initial contact between the large ribosomal subunit and the Sec61 complex is important for efficient insertion of a nascent polypeptide into the translocation pore. In contrast, point mutations in L6 of Sec61p inhibit cotranslational translocation without significantly reducing the ribosome-binding activity, indicating that the L6 and L8 sec61 mutants affect different steps in the cotranslational translocation pathway.
Centrosome fragments and microtubules are transported asymmetrically away from division plane in anaphase
Authors: Rusan Nasser M. , Wadsworth Patricia
Published: January 2005

Spinning disc confocal microscopy of LLCPK1 cells expressing GFP-tubulin was used to demonstrate that microtubules (MTs) rapidly elongate to the cell cortex after anaphase onset. Concurrently, individual MTs are released from the centrosome and the centrosome fragments into clusters of MTs. Using cells expressing photoactivatable GFP-tubulin to mark centrosomal MT minus ends, a sevenfold increase in MT release in anaphase is documented as compared with metaphase. Transport of both individually released MTs and clusters of MTs is directionally biased: motion is directed away from the equatorial region. Clusters of MTs retain centrosomal components at their focus and the capacity to nucleate MTs. Injection of mRNA encoding nondegradable cyclin B blocked centrosome fragmentation and the stimulation of MT release in anaphase despite allowing anaphase-like chromosome segregation. Biased MT release may provide a mechanism for MT-dependent positioning of components necessary for specifying the site of contractile ring formation.
Hypoxia-induced neutrophil survival is mediated by HIF-1α–dependent NF-κB activity
Authors: Walmsley Sarah R. , Print Cristin , Farahi Neda , Peyssonnaux Carole , Johnson Randall S. , Cramer Thorsten , Sobolewski Anastasia , Condliffe Alison M. , Cowburn Andrew S. , Johnson Nicola , Chilvers Edwin R.
Published: January 2005

Neutrophils are key effector cells of the innate immune response and are required to migrate and function within adverse microenvironmental conditions. These inflammatory sites are characterized by low levels of oxygen and glucose and high levels of reductive metabolites. A major regulator of neutrophil functional longevity is the ability of these cells to undergo apoptosis. We examined the mechanism by which hypoxia causes an inhibition of neutrophil apoptosis in human and murine neutrophils. We show that neutrophils possess the hypoxia-inducible factor (HIF)-1α and factor inhibiting HIF (FIH) hydroxylase oxygen-sensing pathway and using HIF-1α–deficient myeloid cells demonstrate that HIF-1α is directly involved in regulating neutrophil survival in hypoxia. Gene array, TaqMan PCR, Western blotting, and oligonucleotide binding assays identify NF-κB as a novel hypoxia-regulated and HIF-dependent target, with inhibition of NF-κB by gliotoxin or parthenolide resulting in the abrogation of hypoxic survival. In addition, we identify macrophage inflammatory protein-1β as a novel hypoxia-induced neutrophil survival factor.
An antagonist peptide mediates positive selection and CD4 lineage commitment of MHC class II–restricted T cells in the absence of CD4
Authors: Kao Henry , Allen Paul M.
Published: January 2005

The CD4 coreceptor works together with the T cell receptor (TCR) to deliver signals to the developing thymocyte, yet its specific contribution to positive selection and CD4 lineage commitment remains unclear. To resolve this, we used N3.L2 TCR transgenic, RAG-, and CD4-deficient mice, which are severely impaired in positive selection, and asked whether altered peptide ligands can replace CD4 function in vivo. Remarkably, in the presence of antagonist ligands that normally deleted CD4+ T cells in wild-type mice, we induced positive selection of functional CD4 lineage T cells in mice deficient in CD4. We show that the kinetic threshold for positive and negative selection was lowered in the absence of CD4, with no evident skewing toward the CD8 lineage with weaker ligands. These results suggest that CD4 is dispensable as long as the affinity threshold for positive selection is sustained, and strongly argue that CD4 does not deliver a unique instructional signal for lineage commitment.
Discovering lymphocyte subsets
Authors: Van Epps Heather L.
Published: January 2005

At a scientific meeting in 1968, Jacques Miller was accused of complicating immunology. He and others suggested that there was not one but two kinds of lymphocytes—one from the thymus and one from the bone marrow. In a pair of groundbreaking articles published in the Journal of Experimental Medicine in 1968, Miller and his student Graham Mitchell proved that two subsets of lymphocytes did exist and identified which subset mediated antibody responses.
Disruption of MRG19 results in altered nitrogen metabolic status and defective pseudohyphal development in Saccharomyces cerevisiae
Authors: Das Maitreyi , Bhat Paike Jayadeva
Published: January 2005

It was previously shown thatMRG19downregulates carbon metabolism inSaccharomyces cerevisiaeupon glucose exhaustion, and that the gene is glucose repressed. Here, it is shown that glucose repression ofMRG19is overcome upon nitrogen withdrawal, suggesting thatMRG19is a regulator of carbon and nitrogen metabolism.β-Galactosidase activity fostered by the promoter ofGDH1/3, which encode anabolic enzymes of nitrogen metabolism, was altered in anMRG19disruptant. As compared to the wild-type strain, theMRG19disruptant showed a decrease in the ratio of 2-oxoglutarate to glutamate under nitrogen-limited conditions.MRG19disruptants showed reduced pseudohyphal formation and enhanced sporulation, a phenomenon that occurs under conditions of both nitrogen and carbon withdrawal. These studies revealed thatMRG19regulates carbon and nitrogen metabolism, as well as morphogenetic changes, suggesting thatMRG19is a component of the link between the metabolic status of the cell and the corresponding developmental pathway.
Molecular analysis of the anaerobic rumen fungus Orpinomyces – insights into an AT-rich genome
Authors: Nicholson Matthew J. , Theodorou Michael K. , Brookman Jayne L.
Published: January 2005

The anaerobic gut fungi occupy a unique niche in the intestinal tract of large herbivorous animals and are thought to act as primary colonizers of plant material during digestion. They are the only known obligately anaerobic fungi but molecular analysis of this group has been hampered by difficulties in their culture and manipulation, and by their extremely high A+T nucleotide content. This study begins to answer some of the fundamental questions about the structure and organization of the anaerobic gut fungal genome. Directed plasmid libraries using genomic DNA digested with highly or moderately rich AT-specific restriction enzymes (VspI and EcoRI) were prepared from a polycentric Orpinomyces isolate. Clones were sequenced from these libraries and the breadth of genomic inserts, both genic and intergenic, was characterized. Genes encoding numerous functions not previously characterized for these fungi were identified, including cytoskeletal, secretory pathway and transporter genes. A peptidase gene with no introns and having sequence similarity to a gene encoding a bacterial peptidase was also identified, extending the range of metabolic enzymes resulting from apparent trans-kingdom transfer from bacteria to fungi, as previously characterized largely for genes encoding plant-degrading enzymes. This paper presents the first thorough analysis of the genic, intergenic and rDNA regions of a variety of genomic segments from an anaerobic gut fungus and provides observations on rules governing intron boundaries, the codon biases observed with different types of genes, and the sequence of only the second anaerobic gut fungal promoter reported. Large numbers of retrotransposon sequences of different types were found and the authors speculate on the possible consequences of any such transposon activity in the genome. The coding sequences identified included several orphan gene sequences, including one with regions strongly suggestive of structural proteins such as collagens and lampirin. This gene was present as a single copy in Orpinomyces, was expressed during vegetative growth and was also detected in genomes from another gut fungal genus, Neocallimastix.