bluuebunny/crossref_metadata_2025_split huggingface dataset:
Membrantechnolgie in der Prozessindustrie – Polymere Membranwerkstoffe
Authors: Rösler H.‐W. 
Published: May 2005

AbstractDer bei weitem größte Anteil von Membranen für die Prozessindustrie wird aus polymeren Werkstoffen hergestellt. In erste Linie werden die Polymere nach der Eignung für den angedachten Trennprozess ausgewählt. Insbesondere die Wechselwirkungen der zu separierenden Moleküle mit dem Membranpolymer sind entscheidend für die Stofftransportmechanismen. Nicht zuletzt bestimmen die auf verschiedene Arten verarbeiteten Polymere auch die chemische, thermische und mechanische Stabilität der technischen Membranen. Durch die Verfügbarkeit spezieller Membranen mit hohen Selektivitäten und Materialeigenschaften lassen sich Trennprozesse realisieren, die mit konventionellen Grundoperationen der Verfahrenstechnik wesentlich aufwendiger sind. Vor diesem Hintergrund wird die Entwicklung von Polymeren und deren Modifizierung auch zukünftig eine entscheidende Rolle spielen.
Entwicklungen und Perspektiven druckgetriebener Membranverfahren
Authors: Kraume M. , Peters T. 
Published: May 2005

AbstractAuf dem Gebiet der Membrantechnik wurden in den letzten vierzig Jahren bedeutsame Innovationen hervorgebracht, die zur Realisierung vielfältiger industrieller Prozesse geführt haben. So werden heute Membranen zur Entsalzung von Meer‐ und Brackwasser sowie zur Behandlung kommunaler und industrieller Abwässer großtechnisch eingesetzt. Für die Reinigung und Aufkonzentrierung von Produkten finden Membranen in der Pharma‐ und der Lebensmittelindustrie ebenso Verwendung wie bei der Herstellung von Grundchemikalien. Gegenwärtig vollziehen sich bedeutende Entwicklungen industrieller Membrantechnik bei der Integration verschiedener Membranprozesse in thermische Trennverfahren und chemische bzw. biologische Umsetzungen. Auf diese Weise werden höhere Produktqualitäten, kompaktere Produktionsanlagen, umweltschonendere und energetisch effizientere Prozesse möglich. Der Beitrag betrachtet derzeit wesentliche, großtechnische Anwendungen der Membrantechnik und erläutert aktuelle Entwicklungen.
Evaluation of sample spin‐polarization from spin‐polarized scanning tunneling spectroscopy experiments
Authors: Yamada T.K. , Vázquez de Parga A.L. , Bischoff M.M.J. , Mizoguchi T. , van Kempen H. 
Published: May 2005

AbstractSpin‐polarized scanning tunneling microscopy has produced a great amount of images presenting magnetic contrast between different magnetic domains with an unsurpassed spatial resolution but getting values like the surface polarization has proven to be a difficult task. We will discuss in detail how to extract this information for the case of manganese layers grown on Fe(001) whiskers. Mn layers adopt a body‐centered‐tetragonal (bct) structure when they are grown on the Fe(001) surface at room temperature. The Mn layers show an antiferromagnetic coupling between the layers. Comparing our spin‐polarized scanning tunneling spectra measured with Fe‐coated W tips with spin‐resolved band structure calculations, we are able to find the value of the sample surface polarization. Also discussed is a method to change the tip magnetization. Finally, the magnetic structure around a screw dislocation on the surface is reviewed. Microsc. Res. Tech. 66:93–104, 2005. © 2005 Wiley‐Liss, Inc.
Pododermal angiogenesis and angioadaptation in the bovine claw
Authors: Hirschberg Ruth M. , Plendl Johanna 
Published: May 2005

AbstractPododermal microvascularization has been suggested to play a key role in the physiological function of the bovine claw and in the pathogenesis of claw diseases. According to our working hypothesis, angiogenesis plays a central role in the physiological and pathological function of the claw and is induced by the pro‐angiogenic vascular endothelial growth factor (VEGF). As a basis for further research, the aim of the present study was to examine the mechanisms of pododermal angiogenesis in the functional adaptation of the microvasculature of the claw in histological serial sections and microcorrosion casts of healthy juvenile and adult claws as well as pathologically altered claws. Scanning electron microscopy of microcorrosion casts allowed assessment of the 3D aspect of pododermal angiogenesis and angioadaptation, and was substantiated by a concomitant examination of a 3D in vitro model of angiogenesis based on cultured bovine microvascular endothelial cells. Particularly in the juvenile, but also in the adult claw, sprouting and intussusceptive angioadaptation was demonstrated and resembled the respective stages of in vitro angiogenesis. Evidence of angiogenic processes was also detected in the pathologically altered claws displaying symptoms of subclinical laminitis and/or the digital dermatitis complex. The detected angioadaptation was visible expression of the increased metabolic demands of the claw caused by the growing body weight load. Angiogenic remodeling of the pododermal angioarchitecture was also the connectional reparative principle in pathologically altered claws. Related research perspectives for prophylaxis and therapy of claw diseases are discussed. Microsc. Res. Tech. 66:145–155, 2005. © 2005 Wiley‐Liss, Inc.
Liquid Chromatography of Polymers under Limiting Conditions of Desorption, 3
Authors: Šnauko Marian , Berek Dušan 
Published: May 2005

AbstractSummary: Liquid chromatography under limiting conditions of desorption (LC LCD) enables the elution of adsorbing macromolecules independent of their size in solution. In this way, polymer species with different adsorptivities can be separated without mutual interference. It is shown on systems of bare silica gel, a tetrahydrofuran/toluene‐mixed eluent and poly(methyl methacrylate)s (PMMA) that LC LCD produces narrow, focused peaks with retention volumes independent of not only polymer molar mass but also, to a large extent, the concentration and volume of the injected sample. Sample capacity of LC LCD is very high, and sample volume can reach as much as 80% of the column pore volume. Reduced sample dilution or even its re‐concentration within the column is important for two‐dimensional separations. Changes in temperature as large as 40 °C only slightly affected retention volumes of the LC LCD‐eluted PMMA. Consequently, the LC LCD method is rather robust and user‐friendly. A practical application of LC LCD for the separation of model polymer blends has been demonstrated. Polystyrene and PMMA of similar molar masses were easily separated in less than four minutes using a small LC LCD column of low efficiency. The LC LCD fractions were successively transported into an on‐line SEC column either directly or after storage in the LC LCD column. The SEC system was equipped with a refractive index detector and a multi‐angle light scattering (MALS) detector. The MALS detector proved a good reproducibility of the molar masses for polymer blend components determined with a combination of LC LCD and SEC. Storage of the fractions within the LC LCD column even for several hours exhibited only a negligible effect on the determined molar mass averages.Scheme of the two‐dimensional chromatograph used. The capillary resistor had a flow resistance similar to that of the SEC column. For further details, see text.imageScheme of the two‐dimensional chromatograph used. The capillary resistor had a flow resistance similar to that of the SEC column. For further details, see text.
N‐Carbamylglutamate protects patients with decompensated propionicaciduria from hyperammonaemia
Authors: Gebhardt B. , Dittrich S. , Parbel S. , Vlaho S. , Matsika O. , Bohles H. 
Published: May 2005

SummaryIn patients with propionic aciduria, the accumulating metabolite propionyl‐CoA causes a disturbance of the urea cycle via the inhibition of N‐acetylglutamate synthesis. Lack of this allosteric activator results in an inhibition of carbamoylphosphate synthase (CPS). This finally leads to hyperammonaemia. In two patients with decompensated propionic aciduria the CPS activator carbamylglutamate was tested for its ability to antagonize the propionyl‐CoA associated hyperammonaemia. Oral carbamyl glutamate administration resulted in a significant increase in ammonia detoxification and could avoid further dialysis therapy. Safe, fast and easy to administer, carbamyl glutamate improves the acute therapy of decompensated propionic aciduria by increasing ammonia detoxification and avoiding hyperammonaemia.
A newborn with severe liver failure, cardiomyopathy and transaldolase deficiency
Authors: Verhoeven N. M. , Wallot M. , Huck J. H. J. , Dirsch O. , Ballauf A. , Neudorf U. , Salomons G. S. , van der Knaap M. S. , Voit T. , Jakobs C. 
Published: May 2005

SummaryThis paper describes the second patient found to be affected with a deficiency of transaldolase (TALDO1; EC 2.2.1.2). Clinically, this patient presented in the neonatal period with several signs of severe liver failure: severe coagulopathy, low serum protein, elevated blood ammonia, and hypoglycaemia. She had generalized oedema, moderate muscular hypotonia, and dysmorphic signs. Liver size was decreased, and the spleen was moderately enlarged. There was severe cardiomegaly. The clinical course was characterized by intractable liver failure and progressive myocardial hypertrophy. The child died at the age of 18 days from respiratory failure. In urine, elevations of erythritol, arabitol and ribitol were found, suggesting a deficiency of transaldolase. Enzyme studies in cultured fibroblasts showed undetectable transaldolase activity. DNA sequence analysis of the TALDO1 gene showed a homozygous missense mutation (575G>A), resulting in an amino acid alteration at position 192 (arginine to histidine, R192H). This amino acid is part of the catalytic site of the transaldolase protein. Discovery of this second patient affected with transaldolase deficiency and liver failure suggests that this disorder has a heterogenous clinical presentation with highly variable severity.
L‐Carnitine and exercise tolerance in medium‐chain acyl‐coenzyme A dehydrogenase (MCAD) deficiency: A pilot study
Authors: Lee P. J. , Harrison E. L. , Jones M. G. , Jones S. , Leonard J. V. , Chalmers R. A. 
Published: May 2005

SummarySkeletal muscle function may be impaired in patients with medium‐chain acyl‐CoA dehydrogenase (MCAD) deficiency, but the value of L‐carnitine in their long‐term management is not clear. This study was designed as a pilot to examine the effects of L‐carnitine on exercise tolerance in patients with MCAD deficiency. Four clinically asymoptomatic MCAD‐deficient patients, aged 8 to 20 years, were studied. Incremental ramp exercise tests were carried out before and after 4 weeks’ treatment with oral L‐carnitine (100 mg/kg per day). During exercise without L‐carnitine supplementation, plasma carnitine concentrations fell, associated with an increased excretion of urinary acylcarnitines, notably acetylcarnitine, hexanoylcarnitine and octanoylcarnitine. L‐Carnitine treatment prevented this fall in plasma carnitine and resulted in greater increases in excretion of acylcarnitines. All four patients showed biologically significant improvement in peak oxygen uptake (peak VO2, 18–32% improvement), VO2 at a heart rate of 170 beats/min (15–23% improvement), VO2 at anaerobic threshold (27–42% improvement), and/or oxygen pulse (10–32% improvement). Exercise tolerance in MCAD‐deficient patients may be improved by short‐term L‐carnitine supplementation. This may be the direct result of improved intramitochondrial homeostasis induced by L‐carnitine in removing accumulating acyl moieties.
Selective antibody immune deficiency in a patient with Smith–Lemli–Opitz syndrome
Authors: Babovic‐Vuksanovic D. , Jacobson R. M. , Lindor N. M. , Weiler C. R. 
Published: May 2005

SummarySmith–Lemli–Opitz syndrome is a rare autosomal recessive disorder characterized by multiple congenital anomalies and various degrees of cognitive deficits. This condition results from a deficiency of 7‐dehydrocholesterol reductase, a critical step in cholesterol biosynthesis. Children with Smith–Lemli–Opitz syndrome have frequent infections, particularly of the respiratory tract. Immunodeficiency, however, is not recognized as a part of this metabolic condition. Frequent infections are usually attributed to a decreased patient mobility and reduced respiratory effort secondary to muscular hypotonia and mental retardation, which are often present in affected individuals. We describe a patient with Smith–Lemli–Opitz syndrome and recurrent respiratory infections who was found to have a selective antibody deficiency. The immunological diagnosis was based on an absent immune response to Pneumovax. She also had no immunological response to hepatitis B vaccine and was unable to break down red cells with isoagglutinin B. Therapy with intravenous IgG (IVIG) was initiated. Infections were less severe, although they still occurred in a high frequency after initiation of the IVIG therapy. This finding prompts the need for a higher index of suspicion for an underlying immune deficiency in patients with Smith–Lemli–Opitz syndrome who present with recurrent and chronic infections. Early recognition and appropriate therapeutic interventions may decrease the severity of infections, prevent potentially fatal infections, and eventually improve the quality of life in these patients.
Cerebral ketone body metabolism
Authors: Morris A. A. M. 
Published: May 2005

SummaryKetone bodies (KBs) are an important source of energy for the brain. During the neonatal period, they are also precursors for the synthesis of lipids (especially cholesterol) and amino acids. The rate of cerebral KB metabolism depends primarily on the concentration in blood; high concentrations occur during fasting and on a high‐fat diet. Cerebral KB metabolism is also regulated by the permeability of the blood–brain barrier (BBB), which depends on the abundance of monocarboxylic acid transporters (MCT1). The BBB's permeability to KBs increases with fasting in humans. In rats, permeability increases during the suckling period, but human neonates have not been studied. Monocarboxylic acid transporters are also present in the plasma membranes of neurons and glia but their role in regulating KB metabolism is uncertain. Finally, the rate of cerebral KB metabolism depends on the activities of the relevant enzymes in brain. The activities vary with age in rats, but reliable results are not available for humans. Cerebral KB metabolism in humans differs from that in the rat in several respects. During fasting, for example, KBs supply more of the brain's energy in humans than in the rat. Conversely, KBs are probably used more extensively in the brain of suckling rats than in human neonates. These differences complicate the interpretation of rodent studies. Most patients with inborn errors of ketogenesis develop normally, suggesting that the only essential role for KBs is as an alternative fuel during illness or prolonged fasting. On the other hand, in HMG‐CoA lyase deficiency, imaging generally shows asymptomatic white‐matter abnormalities. The ability of KBs to act as an alternative fuel explains the effectiveness of the ketogenic diet in GLUT1 deficiency, but its effectiveness in epilepsy remains unexplained.
Keratan sulphate levels in mucopolysaccharidoses and mucolipidoses
Authors: Tomatsu S. , Okamura K. , Maeda H. , Taketani T. , Castrillon S. V. , Gutierrez M. A. , Nishioka T. , Fachel A. A. , Orii K. O. , Grubb J. H. , Cooper A. , Thornley M. , Wraith E. , Barrera L. A. , Laybauer L. S. , Giugliani R. , Schwartz I. V. , Frenking G. Schulze , Beck M. , Kircher S. G. , Paschke E. , Yamaguchi S. , Ullrich K. , Haskins M. , Isogai K. , Suzuki Y. , Orii T. , Kondo N. , Creer M. , Okuyama T. , Tanaka A. , Noguchi A. 
Published: May 2005

SummaryThe mucopolysaccharidoses (MPS) is characterized by accumulation of glycosaminoglycans (GAGs), and mucolipidosis (ML) by accumulation of GAGs and sphingolipids. Each type of MPS accumulates specific GAGs. The lysosomal enzymes N‐acetylgalactosamine‐6‐sulphate sulphatase and β‐galactosidase involve the stepwise degradation of keratan sulphate (KS). Deficiency of these enzymes results in elevation of KS levels in the body fluids and in tissues, leading to MPS IV disease. In this study, we evaluated blood and urine KS levels in types of MPS and ML other than MPS IV. Eighty‐five plasma samples came from MPS I (n=18), MPS II (n=28), MPS III (n=20), MPS VI (n=3), MPS VII (n=5) and ML (n=11) patients while 127 urine samples came from MPS I (n=34), MPS II (n=34), MPS III (n=32), MPS VI (n=7), MPS VII (n=9) and ML (n=11) patients. KS levels were determined using the ELISA method. Plasma KS levels varied with age in both control and patient populations. In all age groups, the mean values of plasma KS in MPS and ML patients were significantly higher than those in the age‐matched controls. Plasma KS values in four newborn patients were above the mean + 2SD of the age‐matched controls (mean, 41 ng/ml). Overall, 85.9% of individual values in non‐type IV MPS and ML patients were above the mean + 2SD of the age‐matched controls. For urine KS levels, 24.4% of individual values in patients were above the mean + 2SD of the age‐matched controls. In conclusion, KS in blood is elevated in each type of non‐type IV MPS examined, in contrast to the conventional understanding. This finding suggests that measurement of KS level provides a new diagnostic biomarker in a wide variety of mucopolysaccharidoses and mucolipidoses in addition to MPS IV.
Increased NO production in lysinuric protein intolerance
Authors: Mannucci L. , Emma F. , Markert M. , Bachmann C. , Boulat O. , Carrozzo R. , Rizzoni G. , Dionisi‐Vici C. 
Published: May 2005

SummaryLysinuric protein intolerance (LPI) is a disorder of dibasic amino acid transport secondary to mutation of the SLC7A7 gene characterized by renal failure, pulmonary alveolar proteinosis, lupus‐like autoimmune symptoms and usually increased plasma citrulline. In order to better understand the underlying mechanism, we studied the plasma and urinary nitrite/nitrate (NO2‐/NO3‐) concentrations in three LPI patients and the in vitro NO2‐ production in cultured fibroblasts. Our data show that NO3‐ levels are increased in the plasma of patients with LPI. Similarly, NO2‐ release in the medium of cultured fibroblasts was increased. On this basis, we hypothesize that some of the poorly understood clinical signs of LPI could be related to the activation of the NO‐citrulline pathway.
Two novel mutations in mitochondrial acetoacetyl‐CoA thiolase deficiency
Authors: Mrázová L. , Fukao T. , Hálovd K. , Gregová E. , Kohút V. , Přibyl D. , Chrastina P. , Kondo N. , Pospišilová E. 
Published: May 2005

SummaryWe report a new patient with acetoacetyl‐CoA thiolase deficiency in whom we found two new missense mutations.
The importance of antennae for pea aphid wing induction in the presence of natural enemies
Authors: Kunert G. , Weisser W.W. 
Published: May 2005

AbstractThe pea aphid Acyrthosiphon pisum Harris has been shown to produce an increasing proportion of winged morphs among its offspring when exposed to natural enemies, in particular hoverfly larvae, lacewing larvae, adult and larval ladybirds and aphidiid parasitoids. While these results suggest that wing induction in the presence of predators and parasitoids is a general response of the pea aphid, the cues and mechanisms underlying this response are still unclear. Tactile stimuli and the perception of chemical signals as well as visual signals are candidates for suitable cues in the presence of natural enemies. In this paper the hypothesis that the aphids' antennae are crucial for the wing induction in the presence of natural enemies is tested. Antennae of pea aphids were ablated and morph production was scored when aphids were reared either in the presence or the absence of predatory lacewing larvae over a six-day period. Ablation of antennae resulted in a drastic drop in the proportion of winged morphs among the offspring, both in the presence and the absence of a predator whereas predator presence increased wing induction in aphids with intact antennae, as reported in previous experiments. The results show that antennae are necessary for wing induction in the presence of natural enemies. Critical re-examination of early work on the importance of aphid antennae and tactile stimuli for wing induction suggests that a combination of tactile and chemical cues is likely to be involved not only in predator-induced wing formation but also for wing induction in response to factors such as crowding in the aphid colony.
The effect of environmentally induced changes in the bark of young conifers on feeding behaviour and reproductive development of adult Hylobius abietis (Coleoptera: Curculionidae)
Authors: Wainhouse D. , Staley J. , Johnston J. , Boswell R. 
Published: May 2005

AbstractYoung plants of Sitka spruce, Scots and Corsican pine were subject to high and low light, and high and low nitrogen treatments in a polyhouse experiment. The effect of treatments on resin duct size and nitrogen concentration in stem bark was determined together with feeding by Hylobius abietis Linnaeus on the stems of ‘intact’ plants and on ‘detached’ stems cut from the plant. Resin duct size was largest on Corsican pine and smallest on Sitka spruce and inherent variation in duct size between the three conifer species appears to determine the pattern of weevil feeding between species. Resin ducts and the flow of resin from them protect the stems of young conifers from weevil feeding not by affecting the total amount of bark eaten but by limiting the depth of feeding and so protecting the inner phloem and cambium. Shallow feeding may increase the likelihood of effective wound repair. Duct size was positively related to plant growth and in particular increased with bark thickness. Overall, ducts were largest in the high light treatment although species differed in their response to the treatment. It is suggested that the effects of plant size, growing conditions and transplantation on susceptiblilty to attack by H. abietis, reported in various studies, may be due to underlying variation in resin duct size or flow rate. The effect on weevils of super-ficial feeding on stems is to increase the time for reproductive maturation by reducing consumption of the inner bark which has a higher nitrogen content.
How host larval age, and nutrition and density of the parasitoid Dinarmus basalis (Hymenoptera: Pteromalidae) influence control of Acanthoscelides obtectus (Coleoptera: Bruchidae)
Authors: Schmale I. , Wäckers F.L. , Cardona C. , Dorn S. 
Published: May 2005

AbstractChoice of the targeted host developmental stage, regulation of parasitoid numbers released and introduction of food supplements are operational factors with a potential to influence the level of biological control. In a closed laboratory storage system maintained over two generations of the host, the impact of these three parameters on the control potential of the parasitoid Dinarmus basalis Rondani was investigated for high populations of larvae of Acanthoscelides obtectus (Say) feeding inside dry common bean seeds Phaseolus vulgaris. The beans were already infested with immature bruchids at the beginning of the storage period to simulate harvest conditions, characterized in a previous study. Treatments resulted in a reduction of 48–75% of the bruchid population within 16 weeks of storage. The best timing of parasitoid release was at the simulated harvest, as later releases reduced the bruchid population only by about half this percentage. Host feeding is postulated to be the key factor involved in the observed difference. The effect of increasing the number of parasitoids strongly depended on host age and food supplement. Addition of vials with honey had no direct effect on the bruchid population or on the parasitoid progeny. The ecological significance of these findings and implications for biological control are discussed.