bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of retention time and organic loading rate on anaerobic acidification and biogasification of dairy manure
Authors: Demirer GN , Chen S
Published: September 2004

Vast amounts of animal manure produced from concentrated animal feeding operations have the potential to be converted into economic gain if the proper processing technology is employed. Anaerobic digestion (AD) is an effective way to convert organic wastes including animal manure into profitable by‐products as well as to reduce the pollution of water, air, and soil caused by these wastes. Two‐phase AD of manure offers several advantages over conventional one‐phase AD. Solids reduction through hydrolysis/acidification might be very significant for animal manure which contains high amounts of solids. However, to date, studies of two‐phase AD of animal manure have been limited to screened manure. Therefore, this study investigated the two‐phase AD of dairy manure with particular emphasis on the effects of retention time and organic loading rate (OLR) on anaerobic acidification and biogasification of unscreened dairy manure. The results indicated that pre‐acidification of dairy manure in daily‐fed continuously‐mixed reactors with no recycle led to significantly high reduction efficiencies of volatile solids and, thus, biogas production in the subsequent methanogenic reactor especially at OLRs of 4–10 g VS dm−3 day−1. However, the extent of the stimulation in the biogas production relative to corresponding feed samples was quite variable (between 6.9 and 64.7%) for different solids retention times and OLR combinations. A relatively lower performance was observed for the high OLRs (20–30 g VS dm−3 day−1) used which was attributed to the possible wash‐out of the acidifiers at the considerably low retention times (1.25–4 days) used. Copyright © 2004 Society of Chemical Industry
Vasectomy‐related changes on sonographic examination of the scrotum
Authors: Reddy Neena M. , Gerscovich Eugenio O. , Jain Kiran A. , Le‐Petross Huong T. , Brock John M.
Published: September 2004

Purpose

The goal of this study was to evaluate the sonographic changes in the epididymis and testis after vasectomy using state‐of‐the‐art high‐resolution equipment.

Methods

We performed a retrospective study of 30 patients with a history of vasectomy and 30 patients without who were referred for scrotal sonography for various indications over a 1‐year period. After excluding findings related to acute pathology, sonographic findings for the epididymis and testis in the 2 groups were tabulated and compared.

Results

The following findings had a statistically higher incidence in the vasectomy group than in the controls: thickened epididymides (53% versus 17%, p < 0.05); epididymal tubular ectasia (43% versus 7%, p < 0.001); and both of the previous 2 findings simultaneously (37% versus 7%, p < 0.01). Sperm granulomas were found in 3 patients in the vasectomy group, and none was seen in the control group. Other findings (eg, epididymal cysts) showed no statistical difference in incidence.

Conclusions

We found a significantly higher incidence of thickened epididymides, epididymal tubular ectasia, a combination of both these findings, and sperm granuloma in the vasectomy group than in the controls. These findings are most likely attributable to postvasectomy obstructive changes and increased intraluminal pressure in the efferent ducts, epididymis, and vas deferens. © 2004 Wiley Periodicals, Inc. J Clin Ultrasound 32:394–398, 2004
Cloacal anomaly simulating megalocystis in the first trimester
Authors: Taipale Pekka , Heinonen Kirsti , Kainulainen Sakari , Seuri Raija , Heinonen Seppo
Published: September 2004

We present a case of cloacal anomaly that simulated megalocystis in the first trimester of gestation of a female fetus. During the second trimester, repeated paracentesis was necessary to treat increasing ascites, oligohydramnios, and hydronephrosis. Our data support findings that ascites presenting with a multiloculated cystic structure on sonography during the second trimester may be typical for cloacal anomalies. Active treatment of the fetal ascites is recommended to improve the child's prospects for survival. © 2004 Wiley Periodicals, Inc. J Clin Ultrasound 32:419–422, 2004
Ultrastructural and immunocytochemical analyses of opioid treatment effects on PC3 prostatic cancer cells
Authors: Baldelli Beatrice , Vecchio Lorella , Biggiogera Marco , Vittoria Emanuela , Muzzonigro Giovanni , Gazzanelli Giancarlo , Malatesta Manuela
Published: September 2004

Some opioid peptides are able to inhibit the growth of human prostatic cancer cells; in particular, the [D‐Ala2,D‐Leu5] enkephalin (DADLE) reduces PC3 cell growth. In order to understand how DADLE decreases cell proliferation, we investigated, by electron microscopy, its effects on PC3 cellular components. PC3 cells were incubated with DADLE and processed for both ultrastructural morphology and immunoelectron microscopy. Some cells were incubated with BrU to determine the transcriptional rate. BrU and DADLE molecules were detected by immunogold techniques and the labeling was quantitatively evaluated. Modifications of some cytoplasmic and nuclear components were observed in DADLE‐treated cells. Moreover, treated cells incorporated lower amounts of BrU than control cells. DADLE molecules were located in the cytoplasm and in the nucleus, especially on mRNA transcription and early splicing sites. Our data suggest that DADLE is able to slow down the synthetic activity of PC3 cells, perhaps interfering with nuclear functions. Microsc. Res. Tech. 64:243–249, 2004. © 2004 Wiley‐Liss, Inc.
Forbidden minors for wye‐delta‐wye reducibility
Authors: Yu Yaming
Published: September 2004

A graph is Y Δ Y reducible if it can be reduced to a single vertex by a sequence of series‐parallel reductions and Y Δ Y transformations. The class of Y Δ Y reducible graphs is minor closed. We found a large number of minor minimal Y Δ Y irreducible graphs: a family of 57578 31‐edge graphs and another 40‐edge graph. It is still an open problem to characterize Y Δ Y reducible graphs in terms of a finite set of forbidden minors. © 2004 Wiley Periodicals, Inc. J Graph Theory 47: 317–321, 2004
Obtaining thermochemical data by the extended kinetic method
Authors: Bouchoux Guy , Sablier Michel , Berruyer‐Penaud Florence
Published: September 2004

A microcanonical analysis of the extended kinetic method is performed using statistical rate calculations based on orbiting transition state theory. The model systems simulate polydentate bases M which exhibit losses of entropy upon protonation of up to 35 kJ mol−1 K−1. It is shown that the correlations using the natural logarithm of the ratio of rate constants vs the proton affinity of the reference bases, at several effective temperatures, lead to correct proton affinity and protonation entropy of the base M of interest. A systematic underestimate of the latter quantity (by 5–15%), mainly due to the use of a linear rather than a polynomial curve fitting procedure, is noted, however. When considering experimental data, more severe underestimates are observed for the protonation entropies of polydentate bases (by 50–90%). The origins of these considerable discrepancies are beyond the limits of the present modeling and remain to be determined. Copyright © 2004 John Wiley & Sons, Ltd.
Influence of droplet size, capillary–cone distance and selected instrumental parameters for the analysis of noncovalent protein–ligand complexes by nano‐electrospray ionization mass spectrometry
Authors: Benkestock Kurt , Sundqvist Gustav , Edlund Per‐Olof , Roeraade Johan
Published: September 2004

It has been suggested in the literature that nano‐electrospray ionization (nano‐ESI) mass spectrometry better reflects the equilibrium between complex and free protein in solution than pneumatically assisted electrospray ionization (ESI) in noncovalent interaction studies. However, no systematic studies of the effects of ionization conditions have been performed to support this statement. In the present work, different instrumental and sample‐derived parameters affecting the stability of noncovalent complexes during analysis by nano‐ESI were investigated. In general, increased values of parameters such as drying gas flow‐rate, ion‐source temperature, capillary tip voltage and buffer concentration lead to a dissociation of ribonuclease A (RNAse)–cytidine 2′‐monophosphate (CMP) and cytidine 5′‐triphosphate (CTP) complexes. The size of the electrosprayed droplets was shown to be an important issue. Increasing the capillary to cone distance yielded an increased complex to free protein ratio when a hydrophilic ligand was present and the reverse effect was obtained with a hydrophobic ligand. Important in this regard is the degree of sampling of ions originating from late‐generation residue droplets, that is, ions present in the droplet bulk. Sampling of these ions increases with longer capillary–cone distance (flight time). Furthermore, when the sample flow‐rate was increased by increasing the capillary internal tip i.d. from 4 to 30 µm, a decreased complex to free protein ratio for the RNAse–CTP system was observed. This behavior was consistent with the change in surface to volume ratio for flow‐rates between 2 and 100 nl min−1. Finally, polarity switching between positive and negative ion modes gave a higher complex to free protein ratio when the ligand and the protein had the same polarity. Copyright © 2004 John Wiley & Sons, Ltd.
Mass spectral study of Boc‐carbo‐β3‐peptides: differentiation of two pairs of positional and diastereomeric isomers
Authors: Srikanth R. , Nagi Reddy P. , Narsimha R. , Srinivas R. , Sharma G. V. M. , Ravinder Reddy K. , Radha Krishna P.
Published: September 2004

A mass spectral study of a series of new Boc‐C‐linked carbo‐β3‐peptides prepared from C‐linked carbo‐β3‐amino acids (Caa) was carried out using liquid secondary ion mass spectrometry (LSIMS), electrospray ionization (ESI) and tandem mass spectrometry. Using the nomenclature of Roepstorff and Fohlman, the positive ion high‐ and low energy collision‐induced dissociation (CID) of [M + H − Boc + H]+ ions of the peptides produce both N‐ and C‐terminus ions, yn+ and bn+ ions, with high abundance and other ions of low abundance. Further, characteristic fragment ions of carbohydrate moiety are observed. In contrast to the CID of protonated peptide acids, the CID of [M − H]− ions of the β3‐peptide acids do not give $\hbox{b}_{{n}}^{-}$ ions and show abundant $\hbox{z}_{{n}}^{-}$ and cn− ions which are insignificant in the former. Two pairs of positionally isomeric Boc‐carbo‐β3‐dipeptides were differentiated by the CID of [M + H]+ ions in LSIMS and ESIMS. The fragment ion [M + H − C(CH3)3 + H]+ formed from [M + H]+ by the loss of 2‐methylprop‐2‐ene is relatively more abundant in the dipeptide Boc‐NH‐β‐hGly‐Caa(S)‐OCH3 (14) containing the sugar moiety at the C‐terminus whereas it is insignificant in Boc‐NH‐Caa(S)‐β‐hGly‐OCH3 (13), which has the sugar moiety at the N‐terminus. Similarly, two pairs of diastereomeric dipeptides were distinguished by the high‐ and low‐energy CID of [M + H]+ ions. The loss of 2‐methylprop‐2‐ene is more pronounced for Boc‐NH‐Caa(R)‐β‐hGly‐OCH3 (17) and Boc‐NH‐Caa(R)‐Caa(S)‐OCH3 (18) isomers whereas it is insignificant for Boc‐NH‐Caa(S)‐β‐hGly‐OCH3 (13) and Boc‐NH‐Caa(S)‐Caa(S)‐OCH3 (2) isomers. This was attributed to a favorable configuration of the carbohydrate moiety favoring the ‘H’ migration involved in the loss of 2‐methylprop‐2‐ene from the [M + H]+ ions of isomers 17 and 18 compared with the unfavorable configuration of the carbohydrate moiety in isomers 13 and 2. Copyright © 2004 John Wiley & Sons, Ltd.
TTV infection in children born to mothers infected with TTV but not with HBV, HCV, or HIV
Authors: Komatsu Haruki , Inui Ayno , Sogo Tsuyoshi , Kuroda Koichi , Tanaka Toshio , Fujisawa Tomoo
Published: September 2004

The TT virus (TTV) was isolated recently from the serum of a patient with post‐transfusion hepatitis. TTV infection is widespread in the general population, and its prevalence increases continuously with age. The pathogenic role of TTV in liver disease remains controversial, and the source of transmission is still unclear. We investigated the pathogenicity and epidemiology of TTV infection in infants born to TTV DNA‐positive mothers. Enrolled in this study were 22 mother–child pairs testing negative for antibodies to hepatitis B, hepatitis C, and the human immunodeficiency viruses (HIVs). The children were followed for 30 months after birth. Serum TTV DNA was detected by N22‐PCR, and the PCR products were cloned and sequenced. The prevalence of TTV infection in children increased with age. Of the 22 children, 13 (59%) became positive for TTV DNA during the follow‐up period. Of these 13 children, 6 (46%) had elevated levels of serum alanine aminotransferase (ALT), although the elevations were transient and mild. TTV viremia was not associated significantly with the abnormal ALT levels. Children with TTV viremia developed neither severe liver disease nor fulminant hepatitis. Phylogenetic analysis showed that, in 11 (85%) of the 13 pairs, the mother and child had the same genotype at the first PCR‐positive time point. Among those 11 mother–child pairs, 6 (55%) had identical TTV nucleotide sequences. However, the genotype of predominant clones changed in 5 (50%) of 10 children who were positive for TTV DNA at two or more time points during the follow‐up period. In conclusion, this study did not provide evidence that TTV infection is related to liver disease in children. Although the main source of TTV infection in children is presumed to be their mothers, transmitted via non‐parenteral routes in the course of daily contact, intrafamilial carriers may also be sources of TTV infection. J. Med. Virol. 74:499–506, 2004. © 2004 Wiley‐Liss, Inc.
Flexible GMRES‐FFT method for fast matrix solution: application to 3D dielectric bodies electromagnetic scattering
Authors: Chen R. S. , Ding D. Z. , Fan Z. H. , Yung Edward K. N. , Chan C. H.
Published: September 2004

In this paper, the electromagnetic wave scattering is analysed by the efficient Krylov subspace iterative fast Fourier transform (FFT) technique in terms of the electric field integral equation (EFIE) for a dielectric body of general shape, inhomogeneity, and anisotropy. However, when the permittivity of the scatter becomes large, the convergence rate of Krylov subspace iterative methods slow down. Therefore, the inner–outer flexible generalized minimum residual method (FGMRES) is used to accelerate the iteration. As a result, nearly 10 times convergence improvement is achieved for high permittivity cases. Copyright © 2004 John Wiley & Sons, Ltd.
Reexpression of vimentin in differentiated neuroblastoma cells enhances elongation of axonal neurites
Authors: Dubey Maya , Hoda Sadaf , Chan Walter K.‐H. , Pimenta Aurea , Ortiz Daniela D. , Shea Thomas B.
Published: September 2004

Vimentin (Vm) is initially expressed by early neuronal precursors in situ and in culture. Vm is essential for neuritogenesis at least in culture and is gradually replaced by neurofilaments (NFs) because of down‐regulation of Vm expression. This period is accompanied by a slowing of axonal elongation. We examined whether continued expression of Vm could foster continued axonal elongation. NB2a/d1 cells differentiated with dibutyryl cAMP were transfected with constructs expressing Vm or the middle‐molecular‐weight NF subunit (NF‐M) each conjugated to green fluorescent protein (GFP). Axonal neurites of cells expressing GFP‐Vm were 30% longer than those of nonexpressing cells, or cells expressing GFP‐M, and exhibited a decrease in neurite caliber. Expression of GFP‐M did not enhance axonal neurite length but significantly increased caliber. These findings provide further evidence of a role for Vm in axonal outgrowth. Culturing of nontransfected cells on laminin increased neurite length, but cells expressing GFP‐Vm demonstrated an equivalent increase whether cultured on laminin or culture plastic. Axonal neurites of cells expressing GFP‐Vm turned to avoid a nonfavorable substrate (nitrocellulose), but culturing of these cells on nitrocellulose did not impair axonal outgrowth. These latter findings indicate that the more robust outgrowth following reexpression of Vm is independent of a favorable or nonfavorable substrate but that axonal neurites of these cells still interact with the substrate to the extent that the substrate can influence directionality. © 2004 Wiley‐Liss, Inc.
Metallothionein I and II mitigate age‐dependent secondary brain injury
Authors: Natale JoAnne E. , Knight Jay Brandon , Cheng Ying , Rome Justin E. , Gallo Vittorio
Published: September 2004

Both the immediate insult and delayed apoptosis contribute to functional deficits after brain injury. Secondary, delayed apoptotic death is more rapid in immature than in adult CNS neurons, suggesting the presence of age‐dependent protective factors. To understand the molecular pathobiology of secondary injury in the context of brain development, we identified changes in expression of oxidative stress response genes during postnatal development and target deprivation‐induced neurodegeneration. The antioxidants metallothionein I and II (MT I/II) were increased markedly in the thalamus of adult C57BL/6 mice compared to mice <15 days old. Target deprivation generates reactive oxygen species that mediate neuronal apoptosis in the central nervous system; thus the more rapid apoptosis observed in the immature brain might be due to lower levels of MT I/II. We tested this hypothesis by documenting neuronal loss after target‐deprivation injury. MT I/II‐deficient adult mice experienced greater thalamic neuron loss at 96 hr after cortical injury compared to that in controls (80 ± 2% vs. 57 ± 4%, P < 0.01), but not greater overall neuronal loss (84 ± 4% vs. 79 ± 3%, MT I/II‐deficient vs. controls). Ten‐day‐old MT I/II‐deficient mice, however, experienced both faster onset of secondary neuronal death (30 vs. 48 hr) and greater overall neuronal loss (88 ± 2% vs. 69 ± 4%, P = 0.02). MT I/II are thus inhibitors of age‐dependent secondary brain injury, and the low levels of MT I/II in immature brains explains, in part, the enhanced susceptibility of the young brain to neuronal loss after injury. These findings have implications for the development of age‐specific therapeutic strategies to enhance recovery after brain injury. © 2004 Wiley‐Liss, Inc.
Interleukin‐1: A master regulator of neuroinflammation
Authors: Basu Anirban , Krady J. Kyle , Levison Steven W.
Published: September 2004

Interleukins 1α and 1β (IL‐1) are very potent signaling molecules that are expressed normally at low levels, but are induced rapidly in response to local or peripheral insults. IL‐1 coordinates systemic host defense responses to pathogens and to injury and not surprisingly it has similar effects within the central nervous system (CNS). Numerous reports have correlated the presence of IL‐1 in the injured or diseased brain, and its effects on neurons and nonneuronal cells in the CNS, but it is only recently that the importance of IL‐1 signaling has been recognized. This article reviews studies that demonstrate that IL‐1 is at or near the top of the hierarchical cytokine signaling cascade in the CNS that results in the activation of endogenous microglia and vascular endothelial cells to recruit peripheral leukocytes (i.e., neuroinflammation). The IL‐1 system thus provides an attractive target for therapeutic intervention to ameliorate the destructive consequences of neuroinflammation. © 2004 Wiley‐Liss, Inc.
Effect of the lanthanide ionic radius on the Raman spectroscopy of lanthanide agardite minerals
Authors: Frost Ray L. , Erickson Kristy L. , Weier Matt L. , McKinnon Adam R. , Williams Peter A. , Leverett Peter
Published: September 2004

Raman microscopy was used to study the Raman spectra of a series of rare earth element agardites ACu6(AsO4)3(OH)6 ·3H2O, where A = lanthanide3+. These minerals have a porous framework similar to that of zeolites with a structure based on (A3+)1−x(A2+)xCu6(OH)6(AsO4)3−x(AsO3OH)x. Two sets of AsO stretching vibrations were found and assigned to the vibrational modes of AsO4 and HAsO4 units. The position of selected bands was found to be sensitive to the lanthanide ionic radius. Raman spectra of the low‐wavenumber region are complex. Bending modes of the AsO4 and HAsO4 units were found to be sensitive to the ionic radius of the lanthanide ion. Linear relationships between positions of the Raman bands were derived, with correlation coefficients >0.90. Copyright © 2004 John Wiley & Sons, Ltd.
Production of fermentable media from vine‐trimming wastes and bioconversion into lactic acid by Lactobacillus pentosus
Authors: Bustos Guadalupe , Moldes Ana Belén , Cruz José Manuel , Domínguez José Manuel
Published: September 2004

Trimmings of vineshoots, an agricultural waste with little use, were hydrolysed with dilute sulphuric acid (1–5%) in order to obtain sugar solutions suitable as fermentation media. The operational conditions for hydrolysis were selected on the basis of both the generation of hemicellulosic sugars (mainly xylose) and glucose and the concentrations of reaction byproducts affecting fermentation (furfural, hydroxymethylfurfural and acetic acid). Hemicellulosic hydrolysates were supplemented with nutrients and fermented with Lactobacillus pentosus, without any previous detoxification stage, to produce lactic acid. Under the best operational conditions assayed (3% H2SO4 and 15 min), 21.8 g lactic acid l−1 was produced (QP = 0.844 g l−1 h−1, YP/S = 0.77 g g−1), which represents a theoretical yield of 99.6%. Acetic acid was the primary byproduct formed from xylose, at about 25% of the lactic acid level. Copyright © 2004 Society of Chemical Industry
Effects of drought stress and its sudden relief on free radical processes in barley
Authors: Goodman Bernard A , Newton Adrian C
Published: September 2004

The generation of free radicals and other paramagnetic species has been investigated by electron paramagnetic resonance (EPR) spectroscopy in leaves of barley plants during and after release of drought stress. Three cultivars were studied; the mlo‐resistant spring barley cultivars, Atem and Krona, along with the cultivar Golden Promise, with the wild‐type dominant Mlo. In the cultivar Atem, which exhibits a partial loss of resistance to powdery mildew after relief of drought stress, the free radical levels were elevated in the drought‐stressed samples compared with those seen in the controls, but they returned rapidly to the control levels after release of the stress. The other two cultivars showed little or no change in the free radical signal for any of the treatments. A sizeable increase in the level of a mononuclear Fe(III) complex was seen in the droughted samples (compared with the levels in the watered controls), and these elevated levels remained after release of the stress. These observations are discussed in the context of molecular processes in the mesophyll cells, where activation of plasma membrane H + ‐ATPase by 14‐3‐3 proteins leads to a decrease in pH. This, in turn, perturbs the Fe(II) speciation in favour of more easily oxidized complexes, and results in the generation of the mononuclear Fe(III) complex. The greater change in free radical activity in Atem as a result of drought stress compared with that seen with the other cultivars indicates that it is affected to a greater extent by the stress. Copyright © 2004 Society of Chemical Industry
Production of a root‐specific flavour compound, 2‐hydroxy‐4‐methoxy benzaldehyde by normal root cultures of Decalepis hamiltonii Wight and Arn (Asclepiadaceae)
Authors: Giridhar P , Rajasekaran T , Ravishankar GA
Published: September 2004

The flavour compound 2‐hydroxy‐4‐methoxy benzaldehyde from normal roots of swallow root (Decalepis hamiltonii) raised in vitro was extracted with dichloromethane, evaporated to dryness and dissolved in ethanol for qualitative (TLC) and quantitative (GC‐MS) analysis. Maximum root biomass and the maximum content of flavour compound (40 ± 2.1 µg g−1 dry weight) were recorded after 45 days of growth on Murashige and Skoog medium containing 1.0 mg l−1 α‐naphthaleneacetic acid. Copyright © 2004 Society of Chemical Industry
Laser induced fusion in boron-hydrogen mixture
Authors: Krainov V P
Published: September 2004

The yield of alpha-particles in nuclear fusion reaction between11B nuclei and protons in solid mixture induced by oblique p-polarized picosecond laser pulses with high laser contrast is derived analytically. The vacuum (Brunel) heating is the main mechanism for electron heating in overdense plasma. Induced inverse bremsstrahlung can be neglected in the electron heating. Nuclei acquire their kinetic energy due to ambipolar diffusion together with heated electrons at the plasma hydrodynamic expansion with the speed of the ionic sound. The yield of alpha-particles is equal to 4 × 103for Nd:glass laser with the peak laser intensity of 2 × 1018W/cm2and the pulse duration of 1.5 ps.
Formation and electrochemical behaviour of poly(pyrrole) coatings on steel substrates
Authors: Hamer W. J. , Koene L. , de Wit J. H. W.
Published: September 2004

This paper focuses on the deposition process and the semi‐conductive properties of PPy layers on steel. The polymerisation of PPy was performed galvanostatically on steel in an aqueous solution of 0.1 M pyrrole and 0.1 M oxalic acid (H2C2O4) using a current density of 1 mA/cm2. The build‐up of a ferrous oxalate (FeC2O4) layer, which seals the seel substrate surface, is initially observed. PPy layers made by this method are always doped with oxalate anions. A mechanism is proposed in which PPy deposits at sites where ferrous oxalate is dissolved. PPy is a semiconductor, just like oxide films formed naturally on some metals. Mott‐Schottky diagrams for 9.0, 11.6 and 15.0 kHz suggests a frequency dependence of the dielectric constant of polypyrrole (εPPy). The flatband potential EFB was about − 0.39 V vs. NHE and the charge carrier density was estimated to be about 5 · 1020 m−3. Also, in earlier work by Rammelt et al. and by Miller and Bockris (using different electrolytes and substrate materials) a frequency dependence has been found for a constant phase element that was used to describe the space charge capacitance CSC. The frequency dependence observed can partly be ascribed to surface roughness, which seems experimentally supported by SEM‐research.
Urban and marine corrosion: Comparative behaviour between field and laboratory conditions
Authors: Iribarren Laco J. I. , Liesa Mestres F. , Cadena Villota F. , Bilurbina Alter L.
Published: September 2004

A detailed study of the corrosion phenomena of carbon steel has been investigated in this work by means of the comparison of field and laboratory tests. Two areas of the metropolitan area of Barcelona (Spain) were selected to carry out the field tests, whereas two different solutions of sodium chloride and sodium hydrogen sulfite were used to simulate the field conditions by means of cyclic laboratory tests. The corrosion rate has been evaluated from the weight loss of the specimens and the morphology surface has been visualized by optical and scanning electron microscopy. Corrosion products and contaminants have been analyzed by X‐ray diffraction and energy‐dispersive X‐ray spectroscopy, respectively. The penetration results can be adjusted to the Passano equation and the corrosivity degree can be assigned in accordance with ISO standards.

A correlation between field and laboratory tests has been found, by comparing the specimens with the same degree of corrosion, showing the validity of the accelerated laboratory tests in order to simulate the field conditions.
Microbial consortium influence upon steel corrosion rate, using the electrochemical impedance spectroscopy technique
Authors: Hernández‐Gayosso M. J. , Zavala‐Olivares G. , Ruiz‐Ordaz N. , García‐Esquivel R. , Mora‐Mendoza J. L.
Published: September 2004

The Electrochemical Impedance Technique was used to evaluate the influence of a microbial consortium, isolated from a gas pipeline, upon API XL52 steel corrosion rate. The bacteria growth exhibited two different kinetics behavior, one for the plancktonic and the other for the sessile phase. The sessile bacteria were found to be the main responsible for the corrosion rate increment observed during the experiments and no relationship between the plancktonic microorganisms and the corrosion rate increment was found.

The diagrams obtained from the electrochemical impedance measurements, indicated a biofilm formation and that the system changed from activation to diffusion control. Although the system was under diffusion control, an increment on the corrosion rate was detected, and a localized corrosion process was induced. The results were complemented with some surface analysis using Scanning Electron Microscopy.
Synthesis and Characterisation of Terminal Carbohydrate Modified Poly(dimethylsiloxane)s
Authors: Henkensmeier Dirk , Abele Bors Cajus , Candussio Anton , Thiem Joachim
Published: September 2004

Summary: In the 1990's, carbohydrate modified silicones were developed as a novel class of hydrophilic modified silicones which are now ready for marketing and industrially available, mainly as ingredients of cosmetic formulations. This report focuses on the synthesis of α,ω‐carbohydrate modified linear poly(dimethylsiloxane)s by hydrosilylation reactions. Thus, a series of carbohydrate derivatives was synthesised and reacted with a hydrodimethylsilyl‐terminated poly(dimethylsiloxane) applying Speier's catalyst. The resulting oils were characterised by MALDI TOF MS and NMR spectroscopy. Deprotection gave a series of novel amphiphilic modified silicones, which were more viscous than their protected analogues, due to hydrogen bonding.

General structure of the amphiphilic carbohydrate modified poly(dimethylsiloxane)s.

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General structure of the amphiphilic carbohydrate modified poly(dimethylsiloxane)s.
Effect of Tacticity on the Structure of Poly(1‐octadecene)
Authors: VanderHart David L. , Pérez Ernesto , Bello Antonio , Vasquez Jaime , Quijada Raúl
Published: September 2004

Summary: A sample of poly(1‐octadecene), synthesized with a highly active heterogeneous Ziegler‐Natta catalyst, has been fractioned with heptane, giving soluble and insoluble fractions. Both fractions and the original polymer have been characterized by size exclusion chromatography, solution and solid‐state 13C NMR, DSC and X‐ray diffraction. The results show that the fractionation occurs on the basis of both molecular mass and tacticity differences, with the atactic content concentrated in the lower molecular mass chains. Thus, the soluble fraction, having a lower average molecular mass than the original sample, consists predominantly of atactic chains, whereas the insoluble fraction is mainly isotactic. The analysis of the solid‐state structure reveals that both atactic and isotactic fractions are able to crystallize, although their crystalline structures are different. The NMR and X‐ray data together support the “most probable” structure for the isotactic polymer advanced by Turner‐Jones. That structure is characterized by an orthorhombic crystal form, where a) the backbone crystallizes in a quaternary helical conformation, b) the sidechains are packed in a way analogous to orthorhombic polyethylene, and c) successive sidechains are conformationally inequivalent. Support for points b) and c) are respectively found in the chemical shift of the sidechains and in the splittings observed for backbone carbons and for some sidechain carbons located near the points of attachment. In addition, there is evidence that the mobility of sidechain sites at points near both the bonded and free ends are not uniform from chain to chain. On the other hand, the crystal form for the atactic polymer shows only sidechain order with some support for the notion that this order approximates the disordered hexagonal rotator phase of the alkanes.

X‐ray diffractograms of the three poly(1‐octadecene) samples.

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X‐ray diffractograms of the three poly(1‐octadecene) samples.
Second Order Nonlinear Optical Performances of Polymers Containing Imidazole and Benzimidazole Chromophores
Authors: Carella Antonio , Centore Roberto , Sirigu Augusto , Tuzi Angela , Quatela Alessia , Schutzmann Stefano , Casalboni Mauro
Published: September 2004

Summary: Condensation polymers based on two different NLO‐active chromophores, namely 2‐[4‐[(4‐N,N‐dihydroxyethylamino)phenylazo]phenyl]‐5(6)‐nitrobenzimidazole (BZI) and 2‐[4‐(4‐N,N‐dihydroxyethylamino)phenylazo]‐4,5‐dicyanoimidazole (IMI), have been synthesized and their basic properties measured. The second order NLO properties of poled polymers were investigated by SHG procedures at different temperatures (35, 65 and 85 °C) and exposure times. Resonance free d33 coefficients (λ = 1 368 nm) took values in the range 1.8–4.0 pm · V−1, but the time stability of their SHG signal was fairly acceptable, particularly for the high Tg (e.g. 188 °C) polymer for which a relaxation time (at 25 °C) of 2.8 years has been determined.

BZI and IMI chromophores.

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BZI and IMI chromophores.
Cellulose Acetate‐graft‐Poly(hydroxyalkanoate)s: Synthesis and Dependence of the Thermal Properties on Copolymer Composition
Authors: Teramoto Yoshikuni , Ama Shoko , Higeshiro Tomokazu , Nishio Yoshiyuki
Published: September 2004

Summary: Several different series of cellulose acetate‐graft‐poly(hydroxyalkanoate)s (CA‐g‐PHAs) were synthesized over a wide range of compositions by the graft copolymerization of lactic acid, L‐lactide, (R,S)‐β‐butyrolactone, δ‐valerolactone and ε‐caprolactone onto the residual hydroxyl positions of CA, by virtue of a suitable catalyst, solvent and procedure for each individual case. To achieve a diversity of molecular architectures of the respective graft copolymer series, the degree of acetyl substitution (acetyl DS) of the CA starting material was also varied, resulting in different levels of the intramolecular density of grafts. The CA‐g‐PHAs thus obtained were subjected to differential scanning calorimetric measurements and the relationship between their molecular structure and thermal transition behavior was estimated, in comparison with some semi‐empirical equations available for polymer blends or comb‐like polymers. In particular, the composition dependence of the Tgs of the graft copolymers was represented well in terms of a formula proposed by Reimschuessel for comb‐like polymers, when CAs of acetyl DS ≈2 were employed as a trunk polymer. The deviation of the glass transition data from the model function was discussed in connection with the manner of graft modification.

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Codes and invariant theory
Authors: Nebe G. , Rains E. M. , Sloane N. J. A.
Published: September 2004

The main theorem in this paper is a far‐reaching generalization of Gleason's theorem on the weight enumerators of codes which applies to arbitrary‐genus weight enumerators of self‐dual codes defined over a large class of finite rings and modules. The proof of the theorem uses a categorical approach, and will be the subject of a forthcoming book. However, the theorem can be stated and applied without using category theory, and we illustrate it here by applying it to generalized doubly‐even codes over fields of characteristic 2, doubly‐even codes over ℤ/2fℤ, and self‐dual codes over the noncommutative ring 𝔽q + 𝔽q u, where u2 = 0. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Nanostructures and Functionalities in Polymer Thin Films
Authors: Stamm Manfred , Minko Sergiy , Tokarev Igor , Fahmi Amir , Usov Denys
Published: September 2004

Several examples of self‐organization in thin polymer films are considered for the fabrication of nanopatterned surfaces and nanoscopic objects. Mixed polymer brushes of statistical distribution at the surface, composed of two immiscible polymers covalently bonded to the substrate phase, segregate in the sub‐micrometer scale. Interplay between lateral and perpendicular (sandwich‐like) segregation effects switching behavior of the thin films upon exposure to different environments. The switching between brush morphologies is used for the fabrication of adaptive/responsive surfaces. Fabrication of nano‐domains based on microphase segregation in block‐copolymer systems is used for structures with lateral dimensions as small as 5‐50 nm. The ordered copolymer structures are applied as templates for the fabrication of membranes, nanofibers and nanoparticles.
Strain‐Controlled Tensile Deformation Behavior and Relaxation Properties of Isotactic Poly(1‐butene) and Its Ethylene Copolymers
Authors: Al‐Hussein Mahmoud , Strobl Gert
Published: September 2004

The tensile deformation behaviour of poly(1‐butene) and two of its ethylene copoloymers was studied at room temperature. This was done by investigating true stress‐strain curves at constant strain rates, elastic recovery and stress relaxation properties and in‐situ WAXS patterns during the deformation process. As for a series of semicrystalline polymers in previous studies, a strain‐controlled deformation behaviour was found. The differential compliance, the recovery properties and the stress relaxation curves changed simultaneously at well‐defined points. The strains at which these points occurred along the true stress‐strain remained constant for the different samples despite their different percentage crystallinities. The well‐defined way in which the different samples respond to external stresses complies with the granular substructure of the crystalline lamellae in a semicrystalline polymer.
Short latency afferent inhibition and facilitation in patients with writer's cramp
Authors: Kessler Kirn R. , Ruge Diane , Ilić Tihomir V. , Ziemann Ulf
Published: September 2004

Patients with writer's cramp (WC) show abnormalities of sensorimotor integration possibly contributing to their motor deficit. We studied sensorimotor integration by determining short‐latency afferent inhibition (SAI) in 12 WC patients and 10 age‐matched healthy controls. A conditioning electrical median nerve stimulus was followed 14 to 36 msec later by transcranial magnetic stimulation of the contralateral primary motor cortex, and motor evoked potentials (MEP) were recorded from the relaxed or contracting abductor pollicis brevis muscle (APB). SAI was normal in WC but during APB relaxation SAI was followed by abnormal MEP facilitation, which was absent during APB contraction and in the controls. These findings suggest that somatosensory short‐latency inhibitory input into the primary motor cortex is normal in WC, whereas a later excitatory input, which very likely reflects the long‐latency reflex II, is exaggerated. © 2004 Movement Disorder Society
Parkinsonism, FXTAS, and FMR1 premutations
Authors: Toft Mathias , Aasly Jan , Bisceglio Gina , Adler Charles H. , Uitti Ryan J. , Krygowska‐Wajs Anna , Lynch Timothy , Wszolek Zbigniew K. , Farrer Matthew J.
Published: September 2004

The presence of late‐onset neurological symptoms in male carriers of premutation expansions of the fragile X mental retardation 1 (FMR1) gene has been described recently. One of the clinical symptoms in this fragile X–associated tremor/ataxia syndrome (FXTAS) is parkinsonism. To test the possible association between expanded FMR1 alleles and Parkinson's disease (PD), we determined the size of the FMR1 CGG repeat in 414 male cases of clinically diagnosed parkinsonism, the majority of whom had PD. None of our patients had expanded FMR1 repeats within the premutation range (55–200 CGG repeats). Five patients (1.2%) carry intermediate‐size alleles (41–54 CGG repeats). Expansions within the FMR1 gene are not associated with PD in our study. © 2004 Movement Disorder Society
On blow‐up rate for sign‐changing solutions in a convex domain
Authors: Giga Yoshikazu , Matsui Shin'ya , Sasayama Satoshi
Published: September 2004

This paper studies a growth rate of a solution blowing up at time T of the semilinear heat equation ut − Δu − ∣u∣p−1 u=0 in a convex domain D in ℝn with zero‐boundary condition. For a subcritical p ∈ (1,(n+2)/(n−2)) a growth rate estimate ∣u(x,t)∣⩽C(T−t)−1/(p−1), x ∈ D, t ∈ (0,T) is established with C independent of t provided that D is uniformly C2. The estimate applies to sign‐changing solutions. The same estimate has been recently established when D=ℝn by authors. The proof is similar but we need to establish Lh – Lk estimate for a time‐dependent domain because of the presence of the boundary. Copyright © 2004 John Wiley & Sons, Ltd.
Evolution completeness of separable solutions of non‐linear diffusion equations in bounded domains
Authors: Galaktionov V. A.
Published: September 2004

As a basic example, we consider the porous medium equation (m > 1)
equation image

where Ω ⊂ ℝN is a bounded domain with the smooth boundary ∂Ω, and initial data $u_0 \thinspace \varepsilon L^{\infty} \cap L^{1}$. It is well‐known from the 1970s that the PME admits separable solutions $u_{k}(x,t) = t^{-1/(m-1)} \psi_{ k}(x), \, k = 0,1,2,\ldots,$, where each ψk ≠ 0 satisfies a non‐linear elliptic equation $\Delta (|\psi_{ k}|^{m-1} \psi_k)+ 1/(m-1) \psi_k = 0\, in \,\Omega, \psi_{ k} = 0\, on \, \partial \Omega$. Existence of at least a countable subset Φ = {ψk} of such non‐linear eigenfunctions follows from the Lusternik–Schnirel'man variational theory from the 1930s. The first similarity pattern t−1/(m−1)ψ0(x), where ψ0 > 0 in Ω, is known to be asymptotically stable as t → ∞ and attracts all nontrivial solutions with u0 ⩾ 0 (Aronson and Peletier, 1981).

We show that if Φ is discrete, then it is evolutionary complete, i.e. describes the asymptotics of arbitrary global solutions of the PME. For m = 1 (the heat equation), the evolution completeness follows from the completeness‐closure of the orthonormal subset Φ = {ψk} of eigenfunctions of the Laplacian Δ in L2. The analysis applies to the perturbed PME and to the p‐Laplacian equations of second and higher order. Copyright © 2004 John Wiley & Sons, Ltd.
Investigation of time‐domain characteristics of thin‐wire antennas
Authors: Li Hui Feng , Chen Zhi Ning , Li Le‐Wei
Published: September 2004

In this paper, the transient response of thin‐wire dipoles is investigated using a time‐domain integral‐equation method. First, an antenna system comprising two straight wire dipoles is numerically analyzed using the direct method and the separation method, and is verified by the measurement. The separation method enables us to consider the transmitting antenna and the receiving antenna separately during the antenna‐system design process. Secondly, the transient response of an antenna excited by pulses with different time duration is investigated. The response strongly depends on the time duration of the pulse. Lastly, the directional characteristics are demonstrated by the gain for dipoles and V‐dipoles. The received pulses by antenna systems composed of V‐dipoles are discussed. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 43: 253–258, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20435
Effects of early seizures on later behavior and epileptogenicity
Authors: Holmes Gregory L.
Published: September 2004

Both clinical and laboratory studies demonstrate that seizures early in life can result in permanent behavioral abnormalities and enhance epileptogenicity. Understanding the critical periods of vulnerability of the developing nervous system to seizure‐induced changes may provide insights into parallel or divergent processes in the development of autism. In experimental rodent models, the consequences of seizures are dependent on age, etiology, seizure duration, and frequency. Recurring seizures in immature rats result in long‐term adverse effects on learning and memory. These behavioral changes are paralleled by changes in brain connectivity, changes in excitatory neurotransmitter receptor distribution, and decreased neurogenesis. These changes occur in the absence of cell loss. Although impaired cognitive function and brain changes have been well‐documented following early‐onset seizures, the mechanisms of seizure‐induced dysfunction remain unclear. MRDD Research Reviews 2004;10:101–105. © 2004 Wiley‐Liss, Inc.
Sleep and arousal mechanisms in experimental epilepsy: Epileptic components of NREM and antiepileptic components of REM sleep
Authors: Shouse M. N. , Scordato J. C. , Farber P. R.
Published: September 2004

Neural generators related to different sleep components have different effects on seizure discharge. These sleep‐related systems can provoke seizure discharge propagation during nonrapid eye movement (NREM) sleep and can suppress propagation during REM sleep. Experimental manipulations of discrete physiological components were conducted in feline epilepsy models, mostly in the systemic penicillin epilepsy model of primary generalized epilepsy and the amygdala kindling model of the localization‐related seizure disorder, temporal lobe epilepsy. The sleep–wake state distribution of seizures was quantified before and after discrete lesions, systemic and localized drug administration, and/or photic stimulation, as well as in relation to microdialysis of norepinephrine. We found that (1) neural generators of synchronous EEG oscillations—including tonic background slow waves and phasic “arousal” events (sleep EEG transients such as sleep spindles and k‐complexes)—combine to promote electrographic seizure propagation during NREM and drowsiness, and antigravity muscle tone permits seizure‐related movement; (2) neural generators of asynchronous neuronal discharge patterns reduce electrographic seizures during alert waking and REM sleep, and skeletal motor paralysis blocks seizure‐related movement during REM; (3) there are a number of similarities between amygdala‐kindled kittens and children with Landau–Kleffner Syndrome (LKS) that suggest a link among seizures, sleep disorders, and behavioral abnormalities/regression. MRDD Research Reviews 2004;10:117–121. © 2004 Wiley‐Liss, Inc.
Localization and early time course of TGF‐β1 mRNA expression in dystrophic muscle
Authors: Gosselin Luc E. , Williams Jacqueline E. , Deering Melissa , Brazeau Daniel , Koury Stephen , Martinez Daniel A.
Published: September 2004

Fibrosis is a common pathological feature observed in muscle from patients with Duchenne muscular dystrophy (DMD). In the dystrophic (mdx) mouse model of DMD, the diaphragm is more severely affected than other skeletal muscles. The level of transforming growth factor‐beta1 (TGF‐β1), an inflammatory cytokine, is significantly elevated in mdx diaphragm. However, little is known about the onset of TGF‐β1 messenger ribonucleic acid (mRNA) expression, or which cells express the mRNA. In this study, we characterized the location and time course of expression of TGF‐β1 mRNA in diaphragm from mdx mice. TGF‐β1 mRNA was significantly elevated in mdx diaphragm at 6 and 9 but not 12 weeks of age, and these changes corresponded with changes in type I collagen mRNA and hydroxyproline concentration. Mononucleated cells localized to areas of fiber necrosis highly expressed the TGF‐β1 transcript in mdx diaphragm. Neutralization of TGF‐β1 by decorin administration resulted in a 40% reduction in the level of diaphragm muscle type I collagen mRNA. These findings support a role for TGF‐β1 during the early stages of fibrogenesis in dystrophic diaphragm muscle. Therapeutic interventions aimed at neutralizing this cytokine may be beneficial in slowing the development of fibrosis in DMD. Muscle Nerve, 2004
Detection of bioradicals by in vivo L‐band electron spin resonance spectrometry
Authors: Fujii Hirotada , Berliner Lawrence J.
Published: September 2004

The applications of in vivo electron paramagnetic resonance (EPR) or electron spin resonance (ESR) spectroscopy have been impressive over a relatively short period despite the many obstacles which had to be overcome, such as dielectric absorption and biodestruction. The loop–gap resonators and modified loop coil systems have emerged as the most suitable resonators for in vivo EPR experiments. This paper briefly discusses instrumental aspects as a prelude to several examples related to the in vivo monitoring and detection of bioradicals. Recent progress in detection of bioradicals induced by drugs or chemicals is discussed with regard to nitrosocompounds, nitric oxide and metals in vivo. A clinical EPR application is also discussed. Copyright © 2004 John Wiley & Sons, Ltd.