bluuebunny/crossref_metadata_2025_split huggingface dataset:
The effects of Nd impurity on the optical, dielectric and electrical properties of PbWO4 single crystals
Authors: Li Weifeng , Huang Hongwei , Feng Xiqi 
Published: September 2005

AbstractA series of Nd‐doped PbWO4 (PWO) crystals are grown using the Czochralski method and their optical and electrical properties are investigated. It is found that the Nd3+ ion characterizes the optical absorption spectra of Nd‐containing crystals. On increasing the concentration of Nd, the optical absorption edge of the crystals shifts to low energy, which results from the defect energy level effect. Similar to other trivalent rare‐earth ions, the improvement of radiation hardness is also achieved in Nd‐doped PWO. Impedance spectroscopy reveals two dielectric loss peaks, which are assigned to [2($ {\rm Nd} ^{3+}_{\rm Pb} $)•–(VPb)″] and [($ {\rm Nd} ^{3+}_{\rm W} $)′′′–($ {\rm Nd} ^{3+}_{\rm Pb} $)•–(VO)••] defect complexes, respectively. High electrical conductivity with an activation energy of about 0.29 ± 0.02 eV at high temperature is present in PWO containing 1.6% Nd. It is of interest that the heavily Nd‐doped PWO could be a high‐temperature ionic conductor. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Luminescence and storage properties of CsBr:Cu and CsBr:CuO crystals
Authors: Zorenko Yu. , Turchak R. , Voznjak T. , Batentschuk M. , Osvet A. , Winnacker A. 
Published: September 2005

AbstractThe absorption, photoluminescence, photo‐stimulated luminescence (PSL) and emission decay of CsBr:Cu and CsBr:CuO crystals have been studied for estimation of the application possibilities of the compounds based on CsBr:Cu as a storage phosphors. The role of the Cu2+ and Cu+ ions in the PSL proceses of the CsBr:Cu compounds was considered. The comparison with the storage properties of the CsBr:Cu and CsBr:CuO crystals with the CsBr:Eu crystals have been provided. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Interfacial modification of amorphous substrates for microcrystalline silicon growth with in situ hydrogen plasma pretreatment
Authors: Park Young‐Bae , Rhee Shi‐Woo , Li Xiaodong 
Published: September 2005

AbstractMicrocrystalline silicon (µc‐Si:H) films have been deposited onto hydrogenated and amorphous Si‐rich silicon nitride and thermal oxide substrates with silane (SiH4)–hydrogen (H2) in remote plasma‐enhanced chemical vapor deposition (RPECVD) at 250 °C, and these films have been investigated. It is found that in situ hydrogen plasma pretreatment of the amorphous substrates prior to µc‐Si:H deposition is effective in reducing the interfacial amorphous transition region. It is believed that this hydrogen plasma pretreatment gives adsorption and nucleation sites by breaking weak Si–N and Si–Si bonds and also removes native Si–O x and hydrocarbon impurities. In the case of SiNx:H surface, surface roughening from atomic hydrogen etching and surface cleaning effects are greater than those for stable thermal oxide. Surface crystallization at the initial stage of the growth can be obtained on amorphous substrate at low temperature without an a‐Si transition layer. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Optoelectronic and electrical properties of TlGaS2 single crystal
Authors: Qasrawi A. F. , Gasanly N. M. 
Published: September 2005

AbstractThe optoelectronic and electrical properties of TlGaS2 single crystals have been investigated by means of room temperature transmittance and reflectance spectral analysis, Hall coefficient, dark electrical resistivity and photocurrent measurements in the temperature range of 200–350 K. The optical data have revealed an indirect and direct allowed transition band gaps of 2.45 and 2.51 eV, an oscillator and dispersion energy of 5.04 and 26.45 eV, respectively, a static dielectric constant of 6.25 and static refractive index of 2.50. The dark Hall coefficient measurements have shown that the crystals exhibit a conductivity type conversion from p‐type to n‐type at a critical temperature of 315 K. Deep donor and acceptor energy levels of 0.37/0.36 eV and 0.66 eV has been calculated from the temperature dependence of Hall coefficient and resistivity, and photocurrent measurements, respectively. The photocurrent decreases with decreasing temperature. The analysis of the photocurrent data have revealed that, the recombination mechanism is linear and supralinear above and below 290 K, respectively. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Fine‐grained sediment in river systems: environmental significance and management issues
Authors: Owens P. N. , Batalla R. J. , Collins A. J. , Gomez B. , Hicks D. M. , Horowitz A. J. , Kondolf G. M. , Marden M. , Page M. J. , Peacock D. H. , Petticrew E. L. , Salomons W. , Trustrum N. A. 
Published: September 2005

AbstractFine‐grained sediment is a natural and essential component of river systems and plays a major role in the hydrological, geomorphological and ecological functioning of rivers. In many areas of the world, the level of anthropogenic activity is such that fine‐grained sediment fluxes have been, or are being, modified at a magnitude and rate that cause profound, and sometimes irreversible, changes in the way that river systems function. This paper examines how anthropogenic activity has caused significant changes in the quantity and quality of fine‐grained sediment within river systems, using examples of: land use change in New Zealand; the effects of reservoir construction and management in different countries; the interaction between sediment dynamics and fish habitats in British Columbia, Canada; and the management of contaminated sediment in USA rivers. The paper also evaluates present programmes and initiatives for the management of fine sediment in river systems and suggests changes that are needed if management strategies are to be effective and sustainable. Copyright © 2005 John Wiley & Sons, Ltd.
Hydrogeomorphic processes affecting riparian habitat within alluvial channel–floodplain river systems: a review for the temperate zone
Authors: Steiger J. , Tabacchi E. , Dufour S. , Corenblit D. , Peiry J.‐L. 
Published: September 2005

AbstractHydrogeomorphic processes within alluvial river systems create, maintain and degrade riparian habitat. The dynamic interactions between water, sediment, aquatic–terrestrial landforms and biotic elements control the functional processes and biodiversity patterns within the riparian zone and, thus, contribute directly to their ecological integrity and societal value. Numerous researchers from different disciplines publish work on the physical, biological, economic and societal functions of the riparian zone within various physiographic areas. The present paper aims to review the hydrogeomorphic processes of unconfined alluvial channel–floodplain rivers within the temperate zone. These processes and their interactions with the biotic environment provide the basis for understanding the physical as well as the ecological functioning of fluvial hydrosystems. The review focuses mainly on the European context, but major advances in riparian research from other continents are also considered. Rehabilitation and management strategies for the riparian zone are summarized and recommendations for further research conclude this review. Copyright © 2005 John Wiley & Sons, Ltd.
Land‐use change, sediment production and channel response in upland regions
Authors: Liébault Frédéric , Gomez Basil , Page Mike , Marden Mike , Peacock David , Richard Didier , Trotter Craig M. 
Published: September 2005

AbstractHuman‐induced modifications of the vegetation cover in river basins may cause strong geomorphic responses by disturbing sediment supply, transport and deposition regimes. The response is particularly noticeable in upland regions, where sensitivity to change is enhanced by strong coupling between river channels and hillslopes, as is exemplified by studies undertaken in the East Coast region, North Island, New Zealand, and in the Southern French Prealps. Both regions have been affected by land‐use change during the past 150 years (deforestation and reforestation) that can be chronologically linked to geomorphic change on hillslopes and on valley floors. In this paper we use these studies to draw attention to: (1) the magnitude of the change in sediment production associated with a modification to the vegetation cover; (2) the impact that reforestation has on the sediment production and the channel system; and (3) the relative influence of anthropogenic and climatic forcing on the channel response. Finally, we consider the manner in which land use has been used as a tool to manage sediment production in France and New Zealand. The results obtained in both regions demonstrate the strong effect that the vegetation cover has on hillslope erosion processes, through its impact on the landsliding threshold (in New Zealand) and the total sediment yield (from paired forested and non‐forested catchments in France). Consideration of channel response serves to emphasize the sensitivity of upland regions to land‐use change, and suggests that the successful discrimination between the respective influences of climatic and land‐use change depends, in large part, upon the ability to detect spatial and chronological links (or, conversely, gaps) between causes and effects. Copyright © 2005 John Wiley & Sons, Ltd.
A review of techniques available for delimiting the erodible river corridor: a sustainable approach to managing bank erosion
Authors: Piégay H. , Darby S. E. , Mosselman E. , Surian N. 
Published: September 2005

AbstractTraditional policies for managing river bank erosion are currently being reconsidered as a result of increased awareness regarding the unsustainable nature of some forms of bank protection, and the role played by bank erosion in providing ecosystem services and supporting geomorphological functions. River managers are therefore increasingly seeking to preserve bank erosion within a defined erodible corridor. This paper provides an overview of the erodible corridor concept, focusing on the provision of guidelines for applying the concept in practice. We argue that a nested approach is required to address management objectives across a range of scales (network scale, reach scale, local scale) and review the different geomorphic tools that are available to help managers define the extent and inner sensitivity of the erodible corridor. These tools include simple rules of thumb such as evaluation of the equilibrium meander amplitude, historical approaches based on overlays of historical channel position, and simulation modelling. The advantages and limitations of each of these tools are discussed. Copyright © 2005 John Wiley & Sons, Ltd.
Pre‐ and post‐reforestation gully development in Mangatu Forest, East Coast, North Island, New Zealand
Authors: Marden Michael , Arnold Greg , Gomez Basil , Rowan Donna 
Published: September 2005

AbstractFollowing clearance of the indigenous forest and conversion of the land to pasture early in the 20th century, gully erosion became a pervasive feature in the headwaters of the Waipaoa River basin, and was notably problematic in the 140‐km2 area now covered by the Mangatu Forest. In this area, before reforestation in 1961, gully erosion affected c. 4% of the terrain. After a 24‐year exotic reforestation programme the area affected by gullies was reduced to 1.5%, but of the eight gullies larger than 10 ha in 1960 none had stabilized by 1988, although four had at least halved in size. Estimates that a gully will stabilize or increase in size under a range of conditions suggest that in the case of gullies < 1 ha in area, formed in terrain underlain by Cretaceous rock, there is a > 80% probability of stabilization after one forest rotation (c. 24 years). For gullies between 1 and 5 ha in area the probability of stabilization is c. 60%. Gullies of 5 ha have an even chance of stabilizing over the time frame of a single rotation. The key determinant is gully size and shape at the time of planting and, within this size range, these relationships were stronger for linear than for amphitheatre‐shaped gullies. Between 1939 and 1988 sediment production from gullies in the portion (76%) of the Mangatu Forest underlain by Cretaceous‐aged rock was c. 22 000 t km−2 yr−1, and during the period of maximum sediment production (1939–1960) they may have accounted for c. 17% of the Waipaoa River's average annual suspended sediment load. Reforestation reduced the contribution to c. 8% in the period between 1970 and 1988. However, the off‐site (downstream) impact of sediment generated by the remaining 420 active gullies in the Waipaoa River catchment is significant, not least on the capacity of the scheme that protects high‐value agricultural land on the Poverty Bay Flats from flooding. A targeted reforestation programme may be an alternative to raising the height of the existing artificial levees. It is estimated that additional exotic plantings totalling c. 15 400 ha (c. 7% of the Waipaoa River basin area) would produce a > 64% reduction in sediment production from gullies on pastoral hillslopes within one forest rotation (c. 24 yr). Copyright © 2005 John Wiley & Sons, Ltd.
Response of a river sediment budget after historical gravel mining (the lower Tordera, NE Spain)
Authors: Rovira A. , Batalla R. J. , Sala M. 
Published: September 2005

AbstractThe channel of the lower Tordera River (Catalan Coastal Ranges) was intensively mined between 1956 and 1987, at an extraction rate 14 times higher than the replenishment rates. Mining caused incision of up to 2 m over the whole reach, leading to damage of infrastructures and affecting the groundwater system. In this paper we analyse the response of the river sediment budget by means of sediment transport measurements (both in suspension and as bedload) and topographic surveys. Historical data on mining activities was used to verify current values of sediment transport and to locate the main extraction areas in the long profile of the river. This has led to an integrated methodology that can be useful for assessing and managing current and future sediment deficits in heavily mined rivers. In the lower Tordera, a minimum of 3 million cubic metres of sand and gravel were extracted, especially from two gravel pits still visible as concavities in the river's longitudinal profile. Nowadays, 15 yr after mining ceased, the river shows during dry periods a general tendency towards aggradation (3.6 mm yr−1 on average and up to 12 mm yr−1 in central sections where mining took place), but a slight long‐term tendency to erode the riverbed. Sediment yield at the entrance of the study reach attains 552 000 t yr−1, while net sediment deposition reaches 16 400 t yr−1 (78% as bedload), mostly during small floods in dry periods. Estimated time for the river to recover pre‐extraction bed‐level is of the order of 420 yr. Copyright © 2005 John Wiley & Sons, Ltd.
Modulating T cell signaling cascades by HMG‐CoA reductase inhibitors
Authors: Waiczies Sonia , Prozorovski Timour , Zipp Frauke 
Published: September 2005

AbstractThe modulation of undesirable immune responses is a novel and exciting property of statins. These drugs were initially designed to lower lipid levels by specifically inhibiting the rate‐limiting enzyme HMGCR (3‐hydroxy‐3‐methylglutaryl (HMG)‐CoA reductase; EC 1.1.1.88; standard protein abbreviation HMG‐CoA reductase), which is important for cholesterol synthesis. Various mechanisms accounting for the anti‐inflammatory properties of statins have been proposed: preliminary studies reported an interference in MHC class II presentation necessary for transmitting antigen‐specific signals to T cells but subsequently a direct impact on various intracellular T cell molecules independent of antigen presentation or T cell receptor triggering was also reported. Several groups including ours have recently reported the benefits of treating various animal models of T cell‐mediated autoimmune disorders such as multiple sclerosis and rheumatoid arthritis with HMGCR inhibitors. Although a plethora of molecular processes have been reported, the main biological alterations responsible for modulating T cell response by statins involve (I) a direct interference in T cell cycle progression and induction of anergy and (II) a shift in the differentiation status of T‐helper (Th) effector cells towards a regulatory phenotype. The impact of statins on the T cellular immune response is discussed here in detail.
New aspects regarding mechanisms of tissue damage in the course of autoimmune demyelination
Authors: Aktas Orhan 
Published: September 2005

AbstractMultiple sclerosis (MS) is a chronic demyelinating disease of the central nervous system (CNS) and the major cause of neurological disability in young adults in Western countries. Over the last decades, it has become evident that the immune system specifically attacks the myelin sheath within the CNS and induces recurrent or persisting neurological deficits in patients. This review focuses on selected new aspects of the underlying mechanisms linking autoimmune demyelination and irreversible brain tissue damage in the course of MS and its animal model, experimental autoimmune encephalomyelitis.
Mitogen activated protein kinase signaling in the kidney: target for intervention?
Authors: de Borst Martin H. , Wassef Lesley , Kelly Darren J. , van Goor Harry , Navis Gerjan 
Published: September 2005

AbstractMitogen activated protein kinases (MAPKs) are intracellular signal transduction molecules, which connect cell‐surface receptor signals to intracellular processes. MAPKs regulate a range of cellular activities including cell proliferation, gene expression, apoptosis, cell differentiation and cytokine production. The MAPK superfamily consists of at least four families: extracellular signal‐regulated kinase (ERK), p38 MAPK, Jun‐NH2‐terminal kinase (JNK), and ERK5. Each of these families exerts particular downstream effects, although interactions have been described. MAPK activity is present in the normal kidney. Moreover, in various types of renal disease, renal MAPK expression is increased. Interventions that provide renoprotection, such as ACE‐inhibition or statin therapy, may reduce renal MAPK expression, suggesting that increased renal MAPK expression is involved in the pathophysiology of renal damage. Studies using specific MAPK inhibitors have been used to further elucidate this role. This review gives an overview of available in vitro data on MAPK activation (focussed on renal cell types), and describes MAPK localization and possible functions in the normal and diseased kidney in man, and in experimental renal disease. Studies reporting the effect of conventional renoprotective intervention on renal MAPK expression are reviewed, as well as the available data on specific MAPK inhibition, both in the clinical and experimental setting. The available data appear to support the potential of MAPK inhibition as a novel intervention strategy in renal disease, but future clinical studies are needed to substantiate this assumption, and to establish its safety.
Protective role of thioredoxin‐1 in cardiovascular systems
Authors: Haendeler Judith 
Published: September 2005

AbstractThe thioredoxin‐1 (Trx‐1) system consists of two oxidoreductases, the thioredoxin‐reductase and Trx‐1. Trx‐1 is a ubiquitously expressed oxidoreductase. The cellular functions of Trx‐1 are wide range. They include protein disulfide reduction, DNA synthesis, protection from apoptosis, redox regulation of a variety of proteins transcription factors and reduction of H2O2, respectively. This review will first focus on the essential role for Trx‐1 in different cardiovascular cells, namely smooth muscle cells, endothelial cells and cardiomyocytes. Thereby, the review will demonstrate the predominant role of Trx‐1 to limit oxidative stress directly due to reactive oxygen species scavenging and by protein‐protein interaction with key signaling molecules. Furthermore, the review will focus on important in vivo studies showing a protective role of Trx‐1 in different cardiovascular diseases. Thus, the Trx system and Trx‐1 could be important future targets to develop clinical therapies for cardiovascular disorders.
Individualization of Single‐Walled Carbon Nanotubes: Is the Solvent Important?
Authors: Kim Dong Sik , Nepal Dhriti , Geckeler Kurt E. 
Published: September 2005

AbstractThe influence of different solvents on the individualization of single‐walled carbon nanotubes (SWNTs) was investigated by several methods. A stable solution of individual SWNTs in o‐dichlorobenzene was obtained by a combination of ultrasonication and ultracentrifugation. Atomic force microscopy height analysis confirmed that the final supernatant solution contained 85 % of individual tubes with a diameter equal to or less than 1.5 nm, which is consistent with the average diameter of arc‐discharge tubes. Both the solvent and the ultracentrifugation speed are important parameters in determining the final degree of individualized SWNTs. Notably, the SWNTs were stable in o‐dichlorobenzene for more than eight months. This technique for obtaining highly individualized SWNTs in an organic solvent is expected to have great potential in many applications, such as functional materials and nanoelectronics.
Ultrasound diagnosis of fetal macrosomia: a comparison of weight prediction models using computer simulation
Authors: Mongelli M. , Benzie R. 
Published: September 2005

AbstractObjectiveTo assess the frequency of the diagnosis of macrosomia in relation to differing weight estimation formulae in unselected pregnancies.MethodsComputer modeling techniques were employed. Computer modeling software generated correlated fetal biometry measurements according to published British standards, from 37 to 41 weeks' gestation. For each set of measurements, estimated fetal weights were obtained by a panel of 18 ultrasound weight formulae. The diagnosis of macrosomia was made if the fetal weight estimate was greater than 4500 g. Cohorts of 5000 pregnancies for each week of gestation were studied.ResultsThe frequency of diagnosis of macrosomia increased progressively with advancing gestational age, with large increases between 40 and 41 weeks. The type of weight estimation formula had a profound influence on the frequency of diagnosis of macrosomia. Five of the formulae tested almost never returned a weight estimate greater than 4500 g. Three formulae yielded false positive rates in excess of 15%. The Hadlock group of formulae yielded frequencies of 0.3% to 14.6%.ConclusionsMost formulae tend to over‐diagnose macrosomia at term. Intervention rates for suspected fetal macrosomia may be influenced by gestational age at the time of scan and the type of fetal weight estimation formula in use. Copyright © 2005 ISUOG. Published by John Wiley & Sons, Ltd.