bluuebunny/crossref_metadata_2025 huggingface dataset:
Carbon and nitrogen mineralization after maize harvest between and within maize rows: a microcosm study using 13C natural abundance
Authors: John Bettina , Ludwig Bernard , Potthoff Martin , Flessa Heiner
Published: June 2004

The sequestration of carbon in soil is not completely understood, and quantitative information about the rates of soil organic carbon (SOC) turnover could improve understanding. We analyzed the effects of the uneven distribution of crop residues after harvest of silage maize on C and N losses (CO2‐C, dissolved organic carbon (DOC) and nitrogen (DON), and NO3–) from a Haplic Phaeozem and on the occurrence of priming effects induced by the decomposition of accumulated maize residues. Soil columns were taken from a continuous maize (since 1961) field after harvest i) between maize stalk rows (Mbare), ii) within the maize rows including a standing maize stalk (Mstalk), and iii) from a continuous rye (since 1878) field after tillage (rye stalk and roots were mixed into the Ap horizon). The soil columns were incubated for 230 days at 8 °C with an irrigation rate of 2 mm 10–2 M CaCl2 per day. Natural 13C abundance was used to distinguish between maize‐derived C (in SOC and maize residues) and older C originating from former C3 vegetation.

The uneven distribution of maize residues resulted in a considerably increased heterotrophic activity within the maize rows as compared with soil between seed rows. Cumulative CO2 production was 53.1 g CO2‐C m–2 for Mstalk and 23.3 g CO2‐C m–2 for Mbare. The contribution of maize‐derived C to the total CO2 emission was 83 % (Mstalk) and 67 % (Mbare). Calculated as difference between CO2‐C release from Mstalk and Mbare, 19 % of the maize residues (roots and stalk) in Mstalk were mineralized during the incubation period. There was no or only a marginal effect of the accumulation of maize residues in Mstalk on leaching of DOC, DON, and NO3–. Total DOC and DON leaching amounted to 2.5 g C m–2 and 0.16 g N m–2 for Mstalk and to 2.1 g C m–2 and 0.12 g N m–2 for Mbare. The contribution of maize‐derived C to DOC leaching was about 25 % for Mstalk and Mbare. Nitrate leaching amounted to 3.9 g NO3–‐N m–2 for Mstalk and to 3.5 g NO3–‐N m–2 for Mbare. There was no priming effect induced by the decomposition of fresh maize residues with respect to CO2 or DOC production from indigenous soil organic carbon derived from C3 vegetation.
Regression analyses of weather effects on the annual concentrations of nitrate in soil and groundwater
Authors: Schweigert Peter , Pinter Nicholas , van der Ploeg Rienk R.
Published: June 2004

To control the groundwater pollution by NO3–, different monitoring programs have been carried out during more than a decade in drinking water catchments in Germany. The monitoring programs are based on agricultural and hydrological data. Atmospheric influences and irregularities of sampling complicate the interpretation of NO3– values in the soil and in the groundwater. To take such complications into account, NO3– time series from a drinking water catchment in Lower Saxony were analyzed by multiple regression. A strong correlation between the precipitation during the fall season and the NO3– content of the soil was found. The NO3– content of the soil is also influenced by the October temperature. While the raw data of NO3– content of the soil did not decrease significantly over time, a highly significant yearly decrease of about 3 kg N ha–1 or 50 % from 1992 to 2002 was observed after atmospheric influences were taken into account. The variability due to precipitation was amplified by changing the date at which samples were taken. The NO3– concentration of the groundwater near the surface decreased yearly by about 10 mg l–1 or 55 % from 1993 to 2001. Beside this decrease, influences of the October temperature and the sampling depth on the NO3– concentration of groundwater were identified. It is concluded that a multiple regression analysis is indispensable in interpreting soil and groundwater NO3– time series of restricted length.
Uncertainties of nonlinearly estimated parameters fro mincubations of soil organic matter
Authors: Böttcher Jürgen
Published: June 2004

Parameters of first‐order mineralization models are commonly estimated from incubation experiments by using nonlinear estimation techniques. The impact of incubation length and especially more or less small measurement errors on estimated mineralization parameters is largely unknown. The objective of this paper is to analyze the influence of errors in mineralization measurements on the nonlinearly estimated parameters, and to find out how the certainty of parameters can be enhanced. CO2 evolution from organic material (forest floor, L layer) of an acid sandy podzol under pine (Pinus silvestris L.) is taken as an example. For the nonlinear parameter estimation, Marquardt's method is used, and to evaluate uncertainties of estimated model parameters, Monte‐Carlo simulations are performed. The results demonstrate that really small measurement errors in the order of random and unavoidable experimental errors may cause serious uncertainties (about 50 %) in the estimated parameters. Parameter uncertainties are the same for cumulative or rate measurements and models. The evaluations based on Monte‐Carlo simulations show that measurement accuracy and incubation length are key factors for the certainty of estimated parameters. Any decrease of measurement errors results in a disproportionate enhancement of parameter certainty. An increase of incubation length up to about 80 % of the time needed to reach 90 % of the maximum cumulative mineralization, t90, is optimal to minimize parameter uncertainty. This optimal incubation length is commonly not known a priori because t90 depends on the a priori unknown mineralization kinetics. A practical way for its determination is an accompanying estimation of the parameters while the incubation is going on, and the experiment may be terminated when incubation length has reached about 80 % of the estimate of t90.
Plaggen Soils: landscape history, properties, and classification
Authors: Blume Hans‐Peter , Leinweber Peter
Published: June 2004

Plaggen soils were produced by farmers in the sandy lowlands of Denmark, NW Germany, Belgium, and the Netherlands by long‐term application of plaggen manure. The present paper summarizes the genesis, the properties, and the landscape impact of plaggen soils. The objectives and methods of plaggen management are outlined. Evidence for the plaggen management can be traced back to the late Bronze Age. It has continued until the last century. Numerous references indicate the geographical expansion of plaggen management over Europe. The various conditions of plaggen soil formation are reflected by their basic physical and chemical properties. Recent investigations of soil organic matter composition in sandy plaggen horizons revealed large proportions of lipids and fatty acids and some similarity with organic matter in Podzol B horizons. Finally, the classification of plaggen soils is discussed. In the World Reference Base of Soil Resources (ISSS/ISRIC/FAO, 1998), most of them are classified as a separate subunit: within the reference soil group of Anthrosols, they differ from other artificially transformed soils, and are classified as Plaggic Anthrosols.
Simulation of chromium transport in the unsaturated zone for predicting contaminant entries into the groundwater
Authors: Buczko Uwe , Hopp Luisa , Berger Wolfgang , Durner Wolfgang , Peiffer Stefan , Scheithauer Markus
Published: June 2004

Heavy metal contaminations in the top‐soil layers can impose serious threats to groundwater quality. A seepage water prognosis of probable future contaminant entries at the groundwater surface has to take into account the emission characteristics of the source zone and the reactive transport of the contaminated leachate through the unsaturated zone. Here, a possible approach is presented, exemplarily for a site contaminated with chromium, encompassing batch elution experiments, unsaturated soil column leaching experiments with flow interruption, soil monolith lysimeter experiments, and numerical modeling of non‐equilibrium solute transport. The prognosis provides a long‐term prediction of Cr concentrations at the groundwater surface. It must be emphasized, that the modeling results are uncertain, because several of the parameters in the simulations can be determined only with significant errors. Additionally, the approach is not applicable routinely for every hazardous waste site. Our study reveals, however, that reactive contaminants can possibly reach the groundwater at hazardous concentrations within very short time.
EBSD investigation of intergranular corrosion attack on low interstitial stainless steel
Authors: Kuníková T. , Wendrock H. , Wetzig K. , Hrivňaková D.
Published: June 2004

Grain boundary effect on corrosion behaviour of low interstitial AISI 316LN austenitic stainless steel after homogenization and heat treatment at 700 and 800°C was investigated by means of Electron Backscattered Diffraction (EBSD) technique. Rapid oxalic acid etch test (ASTM A262‐ practice A) was used to determine steel susceptibility to intergranular corrosion. An attempt to quantify oxalic acid etch test results was also made.

Beneficial effect of low carbon and nitrogen content on grain boundary precipitation and corrosion was observed. No changes neither in grain orientations nor in grain boundary types between sensitised and non‐sensitised steel states using orientation measurements were recorded. Twin boundaries were found in all samples with highest amount and only small occurrence changes. CSL categorizations showed only little increase of special boundary fractions with increasing time and temperature of heat treatment. Irrespective to annealing conditions a continued network of random boundaries was retained. Additionally, based on misorientation measurement of 50 grooved grain boundaries, a tendency for preferred attack of high angle boundaries (30–55°) was noted.
Influence of testing parameters on the corrosion rate of magnesium alloys
Authors: Kühlein M. , Galovsky U.
Published: June 2004

In sodium chloride solutions alloy composition, phases, microstructure and grain size influence the corrosion behaviour of magnesium alloys. Concentration and distribution of the critical impurities iron, nickel and copper affect the corrosion performance strongly.

Salt spray tests according to ASTM B 117 or DIN 50021 are used to control quality of magnesium alloys. Results of these tests often estimate alloy subcontractors and are therefore very important to placing.

Standards specify test solution, test temperature and position of specimens during test in the salt spray chamber. Standards not prescribe preparation of test specimens, exposure period, handling of the specimens after salt spray test nor the interpretation of the results. Results of salt spray tests can be only compared, provided that test conditions are exactly given. Whether the standards fulfil the above described criteria, will be shown by extensive investigations. Therefore the influence of exposure period, surface condition and microstructure was investigated.
Characterisation and corrosion of spot welds of austenitic stainless steels
Authors: Somervuori M. , Johansson L.‐S. , Heinonen M. H. , van Hoecke D. H. D. , Akdut N. , Hänninen H. E.
Published: June 2004

The corrosion resistance of spot‐welded and induction‐heated austenitic stainless steels EN 1.4301 and EN 1.4318 was investigated in 3.5% sodium chloride solution at ambient temperature. In potentiostatic measurements pitting corrosion of spot‐welded and induction‐heated samples occurs at lower potentials than in the base materials. The corrosion pits initiate on the heat‐tinted areas. In immersion tests the surface of the spot welds was not attacked but crevice corrosion was found between the sheets around the spot welds. The compositions and structures of the heat‐tinted oxides were investigated by surface spectroscopy. The results indicate the yellow, red and blue oxides to have a double‐layered structure with an iron‐rich and chromium‐depleted outer layer and a less iron and more chromium containing inner layer. A chromium‐depleted layer was found in the base material under the yellow heat‐tinted oxide on an induction‐heated sample. Significant amounts of copper contamination were found on the spot‐weld surface near the weld edge.
Untersuchungen des Korrosionsverhaltens ausgewählter Wärmeaustauscherwerkstoffe in Natriumacetat‐Trihydrat‐Schmelze für den Anwendungsfall Latentwärmespeichersysteme
Authors: Brandt B. , Stimming U.
Published: June 2004

In den letzten Jahren haben sich die Entwicklungsaktivitäten auf dem Gebiet der Latentwärmespeicherung erheblich verstärkt. Grund dafür ist die Suche nach Energiespeichern mit höherer Effizienz und die verstärkte Nutzung der z. T. unregelmäßig anfallenden regenerativen Energien sowie von Abwärme. Der besondere Vorteil der Latentwärmespeicherung besteht in der hohen Energiespeicherdichte, die bei ausgewählten Speichermaterialien am Schmelzpunkt erreicht werden kann, und die daraus resultierende Platzeinsparung sowie die nahezu konstante Temperatur. Eine wesentliche Aufgabe bei der Entwicklung solcher Speichersysteme ist die Erhöhung der Langzeitstabilität, speziell die Korrosionsstabilität ausreichend wärmeleitfähiger Metalle, die als Wärmeaustauschermaterial verwendet werden. Das Wärmeaustauschermaterial hat dabei die Funktion, die Wärme oder Kälte von einem Wärmeübertragungsmedium, z. B. Wasser, das die Energie von einer externen Quelle aufgenommen hat, auf das Speichermaterial zu übertragen. Bei den Speichermaterialien hat sich das Natriumacetetat‐Trihydrat mit einem Schmelzpunkt von 58°C als besonders vorteilhaft erwiesen. Eine wichtige Aufgabe war daher die Untersuchung des Korrosionsverhaltens und die Ableitung geeigneter Wärmeaustauschermaterialien. Im vorliegenden Beitrag werden wichtige Ergebnisse der Untersuchung ausgewählter Metalle bei 80°C in Natriumacetat‐Trihydrat‐Schmelze vorgestellt. Dem analysenreinen Natriumacetat‐Trihydrat wurden außerdem gezielt die korrosionsbeeinflussenden Verunreinigungen Chlorid, Sulfat und Karbonat, die im wesentlich preisgünstigeren Salzhydrat technischer Qualität vorkommen können, zugesetzt. Darüber hinaus wurde der Zusatz von Grafit (zur Erhöhung der Wärmeleitfähigkeit) sowie der Zutritt von Luft untersucht. Aus den Untersuchungen wurden mehrere, für den genannten Anwendungsfall besonders aussichtsreiche Metalle abgeleitet.
Polyethylenes Having Well‐Defined Bimodal Molecular Weight Distributions Formed with Bis(phenoxy‐imine) Zr Complexes
Authors: Tohi Yasushi , Nakano Takashi , Makio Haruyuki , Matsui Shigekazu , Fujita Terunori , Yamaguchi Tsutomu
Published: June 2004

Summary: Bis(phenoxy‐imine) Zr complexes with MAO activation can produce polyethylenes with well‐defined bimodal molecular weight distributions. Polymerization behavior indicates that minor changes in the ligand structures can have a significant effect on the modality of the resulting polyethylenes. Although there is no direct relationship between the bimodal catalytic behavior and the structure of a precatalyst complex in solution, a precatalyst complex having a methyl or methoxy group para to the phenoxy‐oxygen inclined to exhibit bimodal behavior whereas that with a pentafluorophenyl group on the imine‐nitrogen displayed unimodal behavior. Polymerization results suggest that bimodal behavior is linked to the presence of two kinds of cationic active species, which arise from different modes of ligand coordination. A qualitative correlation was found between the calculated amounts of possible cationic active species and the uni‐ and bimodal catalytic behavior. Based on the results obtained, we concluded that the bimodal polyethylenes are produced by two kinds of cationic active species having two available cis‐located sites with cis‐N, trans‐O and cis‐N, cis‐O arrangements. The results introduced herein are rare examples of the production of well‐defined bimodal polyethylenes using a single precatalyst.

Bis(phenoxy imine) Zr complexes can produce well‐defined bimodal polyethylenes.

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Bis(phenoxy imine) Zr complexes can produce well‐defined bimodal polyethylenes.
Functionalization of Shortened Single‐Walled Carbon Nanotubes with Poly(p‐dioxanone) by “Grafting‐From” Approach
Authors: Yoon Kuk Ro , Kim Wan‐Joong , Choi Insung S.
Published: June 2004

Summary: It has been a real challenge to form carbon nanotube (CNT)/polymer composites where CNTs are well‐dispersed in the polymer matrix and the interactions between CNTs and polymers are effectively strong. In this paper, we applied surface‐initiated, ring‐opening polymerization (SI‐ROP) of p‐dioxanone (PDX) to shortened single‐walled carbon nanotubes (s‐SWCNTs) and successfully formed s‐SWCNT/PPDX composites (see Figure). Due to intimate interactions between s‐SWCNTs and PPDX, we observed dramatic changes in PPDX properties upon the formation of the composites: 10%‐weight‐loss‐temperature of PPDX increased by 20 °C (measured by thermogravimetric analysis) and the patterns of Tg and Tm were greatly altered. We did not observe any noticeable peaks from the composite up to 120 °C in differential scanning calorimetry (DSC), while DSC data of PPDX itself showed Tg and Tm at −13.4 and 103 °C respectively.

Schematic representation of the procedure for formation of s‐SWCNT/PPDX composites.

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Schematic representation of the procedure for formation of s‐SWCNT/PPDX composites.
β‐Cyclodextrin Pseudopolyrotaxanes with π‐Conjugated Polymer Axles
Authors: Yamaguchi Isao , Kashiwagi Kohki , Yamamoto Takakazu
Published: June 2004

Summary: β‐Cyclodextrin (β‐CD) pseudopolyrotaxanes containing poly(thiophene‐2,5‐diyl), PTh, or poly(3‐methylthiophene‐2,5‐diyl)s, P3MeThs, as an axle were prepared. Structures of the pseudopolyrotaxanes and their inclusion behavior with β‐CD were investigated. The UV‐vis measurements revealed that inclusion of P3MeThs by β‐CD depended on the flexibility of the main chain and their molecular weight.

Formation of the inclusion complex of β‐CD and PTh.

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Formation of the inclusion complex of β‐CD and PTh.
The Formation of Ordered Nanoholes in Binary, Chemically Similar, Symmetric Diblock Copolymer Blend Films
Authors: Xuan Yu , Peng Juan , Wang Hanfu , Li Binyao , Han Yanchun
Published: June 2004

Summary: Binary symmetric diblock copolymer blends, that is, low‐molecular‐weight poly(styrene‐block‐methyl methacrylate) (PS‐b‐PMMA) and high‐molecular‐weight poly(styrene‐block‐methacrylate) (PS‐b‐PMA), self‐assemble on silicon substrates to form structures with highly ordered nanoholes in thin films. As a result of the chemically similar structure of the PMA and the PMMA block, the PMMA chain penetrates through the large PMA block that absorbs preferentially on the polar silicon substrate. This results in the formation of nanoholes in the PS continuous matrix.

An atomic force microscopy image of the thin film obtained from the blend of low‐molecular‐weight PS‐b‐PMMA and high‐molecular‐weight PS‐b‐PMA. The regular array of nanoholes in the films surface is clearly visible.

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An atomic force microscopy image of the thin film obtained from the blend of low‐molecular‐weight PS‐b‐PMMA and high‐molecular‐weight PS‐b‐PMA. The regular array of nanoholes in the films surface is clearly visible.
Association Equilibria Theory for Polymers in Mixed Solvents with Specific Interactions
Authors: Soria Vicente , Figueruelo Juan E. , Abad Concepción , Campos Agustín
Published: June 2004

Summary: Hydrogen bonding plays an important role in determining the physical and thermodynamic properties of polar fluids. Theoretical and experimental aspects of polymers, in mixed solvents with hydrogen‐bonding‐specific interactions, are investigated using a simple association model based on the theory of association equilibria developed by Pouchlý et al. The thermodynamic non‐idealities are accounted for using a modified Flory‐Huggins theory with effective gij parameters. The entropic term of the above formalism has been formulated taking into account the polymer segment‐solvent as well as the solvent‐solvent hydrogen‐bond formation. Four equilibrium constants are introduced to make a realistic picture between the associated and non‐associated species. By application of “multiple association equilibria theory”, sorption coefficients λ and Y have been deduced for the ternary systems with specific interactions i.e., alcohol(C1–C3)/heptan‐3‐one/poly(N‐vinyl pyrrolidone). Numerical values for the self‐association constants of the alcohols, association constants for the alcohols and ketone and for the alcohols and polymer, have been evaluated. These were determined as parameters adjusting best the predicted values of both preferential solvation, λ, and the second virial coefficient, A2, to experimental ones.

Comparison of the theoretical (lines) and experimental (points) λ values as a function of propanol/heptan‐3‐one mixture composition for diverse poly(N‐vinyl pyrrolidone) samples. PVP‐K90 (, ×); PVP‐700K (, ⋄); PVP‐K40 (, ♦); PVP‐K24 (, ▴); and PVP‐K15 (, ▪).

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Comparison of the theoretical (lines) and experimental (points) λ values as a function of propanol/heptan‐3‐one mixture composition for diverse poly(N‐vinyl pyrrolidone) samples. PVP‐K90 (, ×); PVP‐700K (, ⋄); PVP‐K40 (, ♦); PVP‐K24 (, ▴); and PVP‐K15 (, ▪).
Verschleißbeständige Fe‐Basislegierungen mit Niobkarbid
Authors: Theisen W.
Published: June 2004

Martensitische Fe‐Basislegierungen des Systems Fe‐Cr‐C finden heute als Hartguss und Werkzeugstahl vielfältige Anwendung. Da ihre FeCr‐Karbide über eine relativ geringe Härte verfügen, wird in diesem Beitrag über neue Legierungen mit primär ausgeschiedenen härteren Niobkarbiden berichtet. Im Mittelpunkt stehen eine sekundär härtende, rissfrei aufschweißbare Hartlegierung, eine warmfester Schichtwerkstoff für Verbundguss, ein weißes Gusseisen und ein korrosionsbeständiger Kaltarbeitsstahl, die hinsichtlich ihrer herstellungsbedingten Gefüge analysiert und bezüglich Furchungsverschleiß untersucht wurden.
Mechanical Properties and Corrosion Resistance of Nitrided or Oxinitrided, and Powder Painted Regular and Interstitial Free (IF) Drawing Steel Sheet
Authors: Rogalski Z. , Łataś Z.
Published: June 2004

Specimens of 0.8 mm thick regular and interstitial free (IF) drawing steel sheet have been nitrided in fluidised bed for 2 hours at 620 °C and 560 °C with and without a post‐oxidation, and slow and accelerated cooling. As a result, surface hardness, yield and tensile strength of the sheets increased considerably without a critical loss of ductility. Resistance welds between the sheets did not lose their original strength after nitriding‐oxinitriding. Nitrided‐oxinitrided at 620 °C and then powder painted sheets, as compared with powder painted raw sheets, were more corrosion resistant in neutral salt spray and climatic tests. Some mechanical and anticorrosion properties of the IF steel sheet that had undergone the nitriding‐oxinitriding processes were definitely better than those of equally processed regular steel sheet.
Untersuchung von Schmelz‐ und Rekristallisationsprozessen sowie Riss‐, Oxid‐ und Porenbildung beim Schweißen
Authors: Abdurakhmanov R.U. , Saidov R.M. , Semmler U. , Matthes K.‐J. , Abdurakhmanov A.R. , Aitureev M.G. , Bohr A.R.
Published: June 2004

Diskutiert werden verschiedene bekannte Methoden der Untersuchung der primären Rekristallisation und der Struktur der Kristallisationsfront. Diese Methoden besitzen eine Reihe von Nachteilen, haben z. T. eine eingeschränkte Aussagekraft und sind häufig sehr aufwändig. Die hier vorgestellte neue Methode basiert auf mikrofotografischer Aufzeichnung der schmelzenden und erstarrenden Metalloberfläche des Schweißbades. Die Nachteile bisheriger Methoden sind überwunden, wobei die neue Methodik neben der primären auch die Untersuchung der sekundären Rekristallisation sowie der Bildung von Rissen, Poren und nichtmetallischen Einschlüssen in der Schweißnaht erlaubt. Der Leistungsumfang der neuen Methodik wird anhand von Anwendungsbeispielen demonstriert.
Vorhersage des Ermüdungsrissausbreitungsverhaltens von Aluminiumlegierungen für Beanspruchungen mit variablen Mittelspannungen
Authors: Rödling S. , Bär J. , Gudladt H.‐J.
Published: June 2004

Für realistische Lebensdauervorhersagen von rissbehafteten Bauteilen muss das Rissausbreitungsverhalten für wechselnde Beanspruchungsamplituden und variable Mittelspannungen bekannt sein. Dazu wurde ein Verfahren entwickelt, mit dem auf der Grundlage von nur zwei Rissausbreitungsexperimenten eine Vorhersage des Rissausbreitungsverhaltens für beliebige Mittelspannungen möglich ist. Neben einer Rissausbreitungskurve für ein konstantes Spannungsverhältnis R wird lediglich ein weiterer Versuch benötigt, bei dem der Schwellenwert durch eine Erhöhung der Unterspannung erreicht wird. Auf der Grundlage dieser beiden Versuche lassen sich die R‐Abhängigkeit des Schwellenwertes und die für entsprechende Rissfortschrittsrechnungen benötigten Konstanten vorhersagen. Das Verfahren liefert eine geschlossene Funktion zur Beschreibung der Rissfortschrittskurven für beliebige Spannungsverhältnisse. Die Modellrechnung wurde anhand experimenteller Daten für die Aluminiumlegierungen 6013 T62 und 2024 T351 verifiziert. Sie zeigt insgesamt sehr gute Übereinstimmungen mit dem Experiment. Die auf diese Weise ermittelbaren Ergebnisse stellen eine wichtige Grundlage für Betriebsfestigkeitsrechnungen an rissbehafteten Bauteilen, insbesondere bei Kollektiven mit variabler Mittelspannung, dar. Das vorgestellte Verfahren bietet somit eine schnelle und damit kostengünstige Möglichkeit zur vollständigen Ermittlung des Rissfortschrittsverhaltens unter variablen Mittelspannungen.
Quality of life in Polish patients with long‐lasting Parkinson's disease
Authors: Żach Marcin , Friedman Andrzej , Sławek Jarosław , Derejko Mirosława
Published: June 2004

The objective of this study was to evaluate possible relationships between quality of life (QoL) of Polish patients with long‐lasting Parkinson's disease and various demographic and clinical factors. The study comprised 141 patients of Movement Disorders outpatient clinics in Warsaw and Gdansk with at least 5 years of the disease duration. Mean age of patients was 68.09 ± 8.51 years, mean duration of disease was 11.87 ± 5.14 years. To assess the quality of life, the Parkinson's Disease Questionnaire (PDQ‐39) was used. Additional questions concerned duration of disease, initial and current treatment and expenses associated with therapy. Self‐perceived symptoms of depression were in our study the most important factor determining QoL. Duration of the disease and expenses related to the treatment also have a significant impact on the QoL. Patient's age and presence of dyskinesia seem to be irrelevant to the quality of life. © 2003 Movement Disorder Society
Parkinson's disease in Ireland: Clinical presentation and genetic heterogeneity in patients with parkin mutations
Authors: Wiley Joseph , Lynch Timothy , Lincoln Sarah , Skipper Lisa , Hulihan Mary , Gosal David , Bisceglio Gina , Kachergus Jennifer , Hardy John , Farrer Matthew J.
Published: June 2004

Early‐onset autosomal recessive parkinsonism is associated with parkin gene mutations. Different parkin mutations occur in many ethnic backgrounds; however, the phenotype may vary. We studied 102 young‐onset (age at onset <60 years) Parkinson's disease (PD) patients. From 102 patients, 40 with early‐onset PD (<45 years at symptomatic onset) were selected for clinical assessment and parkin gene molecular analysis for duplications/deletions and point mutations. We identified parkin mutations in 7 of 40 early‐onset patients; including novel compound heterozygotes and potential splice site changes. The mean age at onset in the 7 parkin mutation‐positive patients was 33 ± 9 years (age range, 18–42 years), marginally lower than that of the 33 parkin‐negative early‐onset patients, 38 ± 7 years (age range, 17–45 years). A family history of PD was present in 4 of 7 patients with parkin mutations, compared with 6 of 33 early‐onset parkin‐negative patients. Overall, parkin mutations were found in 4 of 10 patients with a positive family history and 3 of 30 patients without a family history of PD. Patients with parkin mutations had more dystonia, dyskinesia, and sleep benefit compared with parkin‐negative patients. We subsequently identified a single point mutation among the 62 young‐onset (age at onset 45 to <60 years). Mutations in the parkin gene may account for ∼17% of early‐onset (age at onset <45 years) parkinsonism in Ireland, in agreement with previous European studies. © 2003 Movement Disorder Society
Partial lesion of thalamic ventral intermediate nucleus after chronic high‐frequency stimulation
Authors: Henderson Jasmine , Rodriguez Michael , O'Sullivan Dudley , Pell Malcolm , Fung Victor , Benabid Alim Louis , Halliday Glenda
Published: June 2004

A 73‐year‐old man with Parkinson's disease underwent thalamic stimulation for disabling tremor with excellent results only when stimulation on. Post‐mortem neuropathology (7 years postoperatively) revealed 60% cell loss within 0.5 mm of the electrode tip. Tremor improvement was attributable to chronic stimulation, not microthalamotomy. © 2004 Movement Disorder Society
Muscle relaxation is impaired in dystonia: A reaction time study
Authors: Buccolieri Alessandro , Avanzino Laura , Marinelli Lucio , Trompetto Carlo , Marchese Roberta , Abbruzzese Giovanni
Published: June 2004

A simple visual reaction time (RT) paradigm was used to investigate whether the velocity of relaxation is impaired in dystonia. In 16 subjects with a clinical diagnosis of adult‐onset focal, segmental or multifocal dystonia and in 15 age‐matched normal controls, the relaxation reaction time (R‐RT) and the contraction reaction time (C‐RT) were compared across different tasks involving the flexor carpi radialis (FCR), biceps brachii (BB) and triceps brachii (TR) arm muscles. In normal controls, the latency of EMG termination (R‐RT) was significantly shorter than the latency of electromyographic (EMG) onset (C‐RT) in the BB and TR muscles, but not in the FCR muscle. In dystonic patients, the latency of EMG termination (R‐RT) was significantly longer than the latency of EMG onset (C‐RT) in the FCR and BB muscles. No significant difference of the C‐RT was observed between patients and controls whereas the R‐RT was prolonged significantly in the BB and TR muscles of patients with dystonia and almost significantly in the FCR muscle. This study indicates that muscle relaxation is abnormal in patients with focal (multifocal or segmental) dystonia. The impaired muscle relaxation may contribute to the longer overlap of agonist–antagonist activities (co‐contraction) typically observed in dystonia and to the slowness of voluntary movement sequencing. © 2004 Movement Disorder Society
A 100% increase of dopaminergic cells in the olfactory bulb may explain hyposmia in Parkinson's disease
Authors: Huisman Evelien , Uylings Harry B.M. , Hoogland Piet V.
Published: June 2004

Hyposmia is one of the most prevalent symptoms of Parkinson's disease. It may occur even before the motor symptoms start. To determine whether the olfactory dysfunctions, like the motor symptoms, are associated with a loss of dopamine, the number of dopaminergic cells in the olfactory bulb of Parkinson's disease patients was studied using tyrosine hydroxylase immunohistochemistry. The quantitative analysis reveals that the total number of tyrosine hydroxylase–immunoreactive neurons in the olfactory bulb is twice as high in Parkinson patients compared to age and gender‐matched controls. Because dopamine is known to inhibit olfactory transmission in the olfactory glomeruli, we suggest that the increase of dopaminergic neurons in the olfactory bulb is responsible for the hyposmia in Parkinson patients. The increase of dopamine in the olfactory bulb explains why olfaction does not improve with levodopa therapy. © 2004 Movement Disorder Society
Minocycline in Huntington's disease: A pilot study
Authors: Thomas Madhavi , Ashizawa Tetsuo , Jankovic Joseph
Published: June 2004

Minocycline is a caspase inhibitor, decreases inducible nitric oxide synthase (iNOS), and has been shown to delay disease progression in the mouse model R6/2 of Huntington's disease (HD). This safety and tolerability study included 30 patients with HD who were given minocycline over a 6‐month period and underwent assessments every 2 months with laboratory studies, the Abnormal Involuntary Movements Scale, the Unified Huntington's Disease Rating Scale, and the Mini‐Mental State Examination. Minocycline was well tolerated during this study period and no serious adverse events were noted. © 2004 Movement Disorder Society
Cerebellar metabolic symmetry in essential tremor studied with 1H magnetic resonance spectroscopic imaging: Implications for disease pathology
Authors: Louis Elan D. , Shungu Dikoma C. , Mao Xiangling , Chan Steven , Jurewicz Eva C.
Published: June 2004

The pathological basis for essential tremor (ET) is not known; however, metabolic changes in the cerebellum can be observed in positron emission tomography (PET) and 1H magnetic resonance spectroscopic imaging (MRSI) studies. Tremor is relatively symmetric in ET, suggesting that underlying metabolic changes could be also symmetric. The degree of metabolic asymmetry in the cerebellum, however, has not yet been studied in ET, and knowledge about distribution and laterality of metabolic changes might shed some light on basic disease mechanisms. We measured brain metabolism (N‐acetylaspartate[NAA]/creatine [tCR]) to obtain an asymmetry index for cerebellar cortical metabolism ET patients compared with that in controls. This index, a percentage, was calculated as |(value right − value left)|/(value right + value left) × 100. Multislice 1H MRSI data were acquired for 20 patients and 11 controls. In ET patients, mean right and left cerebellar cortical NAA/tCR values were 1.61 ± 0.42 and 1.55 ± 0.38, respectively, compared with 1.81 ± 0.62 and 1.87 ± 0.49 in controls. The difference between right and left cerebellar cortical NAA/tCR was also calculated for each subject. In ET patients, the mean right‐left difference was 0.14 ± 0.11, compared with 0.32 ± 0.27 in controls (P = 0.016). The mean cerebellar cortical asymmetry index was low in ET (8.8 ± 6.1%), one‐half of that in controls (17.0 ± 13.7%, P = 0.027). These data suggest that pathological lesions in ET patients, which remain elusive, might be distributed similarly in each cerebellar cortex. Postmortem studies are needed to confirm these preliminary imaging results. © 2004 Movement Disorder Society
Neuropathology of primary restless leg syndrome: Absence of specific τ‐ and α‐synuclein pathology
Authors: Pittock Sean J. , Parrett Timothy , Adler Charles H. , Parisi Joseph E. , Dickson Dennis W. , Ahlskog J. Eric
Published: June 2004

The neuroanatomical substrate for restless legs syndrome (RLS) is unknown. We identified 4 patients with idiopathic RLS who came to post‐mortem examination, where brain and spinal cord tissue were available for neuropathological assessment. Lewy bodies were not identified and α‐synuclein immunohistochemistry was uniformly negative. Neurofibrillary tangle pathology was variable and nonspecific. These findings suggest that τ‐ or α‐synuclein brain pathology is not a component of primary RLS. Although chronic ischemic changes were found in all 4 cases, these were probably incidental. The absence of diagnostic microscopic brain or spinal cord pathology suggests that the pathologic substrate may be neurochemical or receptor based. © 2004 Movement Disorder Society
Restless legs syndrome due to interferon‐α
Authors: LaRochelle Jeffrey S. , Karp Barbara I.
Published: June 2004

A patient developed restless legs symptoms paralleling the course of interferon‐α (IFNα) therapy for chronic hepatitis C. Symptoms began during a course of IFNα, resolved with its suspension, and recurred on rechallenge. Restless legs syndrome may thus be an adverse effect of IFNα treatment. © 2004 Movement Disorder Society
Reconstruction of the hand and upper limb with free flaps based on musculocutaneous perforators
Authors: Chen Hung‐Chi , Tang Yueh‐Bih , Mardini Samir , Tsai Bo‐Wen
Published: June 2004

Since the advent of perforator flaps, a wide variety of applications have been documented. This study focuses on free flaps based on musculocutaneous perforators, because they have not been well‐described in the literature of upper‐limb reconstruction. They can be trimmed to be thin and pliable, and may provide large flaps with multiple components on the same pedicle to facilitate three‐dimensional inset of flaps. Microvascular free flaps based on musculocutaneous perforators were performed in 36 cases for reconstruction of the thumb and thenar web, palm, dorsum of the hand, wrist, and forearm. They included the anterolateral thigh perforator flap (27 cases), thoracodorsal perforator flap (5 cases), and deep inferior epigastric perforator flap (4 cases). In 2 other cases not included in this series, the thoracodorsal perforator flap could not be elevated due to anatomical variations. There was no failure in this series, but complications included: 1) hematoma in 2 cases, and 2) infection in 2 cases with flap rim necrosis which was treated by a local rotation flap and skin graft. The thin flaps facilitated secondary reconstructive procedures, and only minor effort was required for the debulking procedure of the flaps. On average, these patients required 2.3 occasions of secondary procedures for further reconstruction following coverage with a perforator flap. The perforator flaps provide medium‐thickness flaps for coverage of large defects in the upper limb with improved aesthetics and function. With careful dissection of the musculocutaneous perforators and primary thinning of the flaps, the use of a perforator flap is quite safe. Preservation of the muscles leads to better preservation of donor‐site functions. Less requirement of secondary debulking procedures is a great advantage. However, caution should be taken in the presence of wound infection. © 2004 Wiley‐Liss, Inc.
Gene transfer into intact fetal skeletal muscle grown in vitro
Authors: Cardoso Sandra M. Pinto , Mutch Philip , Scotting Paul J. , Wigmore Peter M.
Published: June 2004

The development of an organ culture system for growing prenatal intercostal muscle in vitro and its use to study gene function is described. Fetal skeletal muscle is relatively inaccessible during the key stages of its development, and this method enables DNA transfections and other manipulations to be carried out. The system allows cell proliferation and differentiation to continue and also maintains the morphology and fiber types of developing muscle. Gene transfer into cultured embryonic intercostal muscle was achieved by square‐pulse electroporation of intact pieces of tissue. Expression of a marker gene (GFP) was found within 5 h and maintained for 2 days in muscle fibers and cells. The technique should enable the function of genes implicated in muscle development and disease to be studied at stages when access is difficult and in a controlled environment. Muscle Nerve 30: 87–94, 2004
Number of contractions to maintain mass and force of a denervated rat muscle
Authors: Dow Douglas E. , Cederna Paul S. , Hassett Cheryl A. , Kostrominova Tatiana Y. , Faulkner John A. , Dennis Robert G.
Published: June 2004

Within 5 weeks, denervated extensor digitorum longus (EDL) muscles of rats lose 66% of mass, 91% of force, and 76% of fiber cross‐sectional area (CSA). We previously determined the parameters of electrical stimulation for denervated rat EDL muscles to generate tetanic contractions sufficient to maintain mass and force close to control values. Using these parameters, we tested the hypothesis that a range exists for number of contractions per day, below and above which values for mass, maximum force, and fiber CSA are lower than values for innervated control muscles. For 5 weeks, denervated EDL muscles were stimulated to generate between 25 and 5000 contractions daily with contractions separated by constant intervals of rest, repeated 24 h per day. Force was not maintained with fewer than 200 or more than 800 contractions daily, whereas mass and fiber CSA were not maintained with fewer than 50 contractions daily. Protocols of stimulation that maintain muscle mass and force during prolonged periods of denervation may minimize problems clinically associated with denervation atrophy. Muscle Nerve 30: 77–86, 2004
Inactivity‐induced modulation of Hsp20 and Hsp25 content in rat hindlimb muscles
Authors: Huey Kimberly A. , Thresher Jeffrey S. , Brophy Colleen M. , Roy Roland R.
Published: June 2004

Denervation decreases small heat shock protein (HSP) content in the rat soleus muscle; however, it is unknown whether this change is due to inactivity or absence of a nerve–muscle connection. Spinal cord isolation (SI) is a model of inactivity with an intact neuromuscular connection. After 7 days of SI, Hsp20 and Hsp25 levels in the soleus, plantaris, and adductor longus muscles were lower than in control rats, whereas Hsp20 was unchanged and Hsp25 increased in the tibialis anterior. The results for the soleus indicate that these small HSPs respond to inactivity and that this response is not influenced by neural activity–independent factors. Furthermore, the data indicate that these HSPs are impacted to a greater degree in muscles that are predominantly slow or have an antigravity function than in flexor muscles. Understanding the regulation of these HSPs during chronic reductions in neuromuscular activity may have valuable applications for conditions such as spinal cord injury. Muscle Nerve 30: 95–101, 2004
Corticosteroid use in the treatment of neuromuscular disorders: Empirical and evidence‐based data
Authors: Bromberg Mark B. , Carter Orly
Published: June 2004

Corticosteroids have been used to treat neuromuscular disorders for many years. With few randomized, controlled trials, efficacy has been established primarily from empirical data. This has led to a range of treatment regimens varying in terms of initial dosing, dosing schedules, and taper rates. The goals of this review were to examine the literature for data concerning corticosteroid pharmacokinetics and for evidence‐based treatment regimens in several prototypic neuromuscular disorders. The results provide a number of sound principles for corticosteroid use, but also indicate that corticosteroid regimens and patient management are largely based on empirical clinical experiences. Muscle Nerve 30: 20–37, 2004
Annexin expression in inflammatory myopathies
Authors: Probst‐Cousin Stefan , Berghoff Corinna , Neundörfer Bernhard , Heuss Dieter
Published: June 2004

The pathogenesis of the inflammatory myopathies is still unclear, making their treatment largely empirical. Improved understanding of the molecular mechanisms of inflammatory muscle injury may, however, lead to the development of more specific immunotherapies. To elucidate a possible pathogenic contribution of calcium‐binding proteins such as the annexins, we immunohistochemically investigated muscle biopsy specimens from patients with dermatomyositis (10 cases), polymyositis (9 cases), and inclusion‐body myositis (4 cases), compared to control cases comprising sarcoid myopathy (3 cases), Duchenne muscular dystrophy (DMD; 4 cases), and normal muscle (3 cases). We found expression of annexins A1, A2, A4, and A6 in the vascular endothelium of all cases. Myofibers expressed annexins A5, A6, and A7 diffusely and weakly in the cytosol, whereas annexins A5 and A7 were also particularly localized to the sarcolemma. In the inflammatory myopathies, in areas of myonecrosis in DMD, and in granulomatous lesions of sarcoid myopathy, reactivity of annexins A1, A2, A4, A5, and A6 was observed in macrophages and T‐lymphocytes. Whereas the latter annexins appear to be nonspecific indicators of activation, annexin A1 upregulation may represent endogenous anti‐inflammatory mechanisms that merit further investigation. Muscle Nerve 30: 102–110, 2004
Free‐radical‐initiated copolymerization of 2‐(2‐naphthylamino)‐2‐oxo‐ethyl methacrylate with methyl methacrylate and styrene
Authors: Erol Ibrahim , Soykan Cengiz
Published: June 2004

A naphthylamino species containing the methacrylate‐based monomer 2‐(2‐naphthylamino)‐2‐oxo‐ethyl methacrylate (NphAOEMA) was synthesized by reacting 2‐chloro‐N‐2‐naphthylacetamide (NphA) with sodium methacrylate in acetonitrile. The acetamide was prepared by reacting 1‐naphthylamine, dissolved in benzene, with chloroacetylchloride. The free‐radical‐initiated copolymerization's of NphAOEMA, with methyl methacrylate (MMA) and styrene (ST), were carried out in dimethylsulfoxide (DMSO) solution at 65 °C using 2,2′‐azobisisobutyronitrile (AIBN) as the initiator with various monomer‐to‐monomer ratios in the feed. The monomer (NphAOEMA) and copolymers were characterized from FT‐IR, 1H and 13C NMR spectral studies. The copolymer compositions were evaluated by determining the nitrogen contents in the polymers. The reactivity ratios of the monomers were determined by the application of the Fineman–Ross and Kelen–Tüdőos methods. The molecular weights (M̄w and M̄n) and polydispersity indices of the polymers were measured by using gel permation chromagtography. The thermal stabilities of the homo and copolymers were investigated by using thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The solubilities and inherent viscosities of the homo and copolymers were also studied. Copyright © 2004 Society of Chemical Industry
Novel thermally resistant polysilphenylenesiloxanes with a high content of vinyl substituents
Authors: Liu Yang , Imae Ichiro , Kawakami Yusuke
Published: June 2004

Polysilphenylenesiloxanes containing various amounts of vinyl substituents (ranging from partial (25 %) to complete (100 %)) on the silicon atoms were synthesized. 29Si NMR spectroscopy revealed that they had a well defined structure, as designed. Unlike the known crystalline poly(tetramethyl‐p‐silphenylenesiloxane), all polymers containing vinyl side groups were amorphous and showed low Tgs, ranging from −52 to −32 °C (from differential scanning calorimetry (DSC)). Dynamic and isothermal thermogravimetric (TG) analyses indicated that they all possessed a greatly improved thermal stability up to 500 °C, and have ultra‐high residual yields at 1000 °C under both inert and oxidative conditions. Polysilphenylenesiloxanes containing a high percentage of vulcanizable vinyl substituents should be excellent candidates for high‐temperature polymers and have potential applications such as heat‐resistant or flame‐retardant materials. Copyright © 2004 Society of Chemical Industry
Preparation of styrene‐acrylic emulsion by using nano‐SiO2 as seeds
Authors: Zhang Faai , Wang Yunpu , Chai Chunpeng
Published: June 2004

A styrene‐acrylic/SiO2 nanoparticle composite emulsion was prepared by using SiO2 nanoparticles as seeds. The effect of factors such as the level of nano‐SiO2, reaction temperature and ultrasound treatment of nano‐SiO2 on the stability of the polymerization reaction was investigated. Water‐resistance of the emulsion was measured. The level of nano‐SiO2 in the emulsion was determined by inductively coupled plasma (ICP) spectrometry. The particle morphology of the emulsion with nano‐SiO2 was observed with transmission electron microscopy (TEM). The kinetics of the polymerization was also studied at various temperatures and various levels of nano‐SiO2. They showed that the level of nano‐SiO2 and reaction temperature had a great influence on the monomer conversion, particle size, coagulum content and viscosity of the emulsion. Nano‐SiO2 treated by ultrasonics can increase the coagulum content greatly, but it does not improve the water resistance of the emulsion. The level of nano‐SiO2 in the emulsion was lower than the theoretical value. The reaction kinetics indicated that the level of nano‐SiO2 had less influence on the reaction rate than the reaction temperature. Even a small amount of nano‐SiO2 can decrease the reaction rate. Copyright © 2004 Society of Chemical Industry