julilili42/papers huggingface dataset:
The Haemodynamic Efficacy of Six Different Compression Stockings from Compression Class 2 in Patients Suffering from Chronic Venous Insufficiency
2000-12-01

Objective: To describe the efficacy of six different compression stockings from compression class 2 on venous haemodynamics in patients with chronic venous insufficiency (CVI). Design: An open, randomised, prospective study. Setting: University Department of Dermatology, Tübigen, Germany. Patients: Twenty-two patients (11 women, 11 men; mean age 55.1 years, SD 10.3 years) suffering from chronic venous insufficiency (CVI) at clinical stages C 1 4E p A s , A 14 , A p , P R . Interventions: The acute effect of six different compresion stockings from compression class 2 (CEN) on venous haemodynamics were measured using dynamic mercury strain gauge plethysmography. At the same time as venous function, the pressure exerted by the compression hosiery was determined under resting conditions and during exercise. Main outcome measures: Resting pressure exerted in the supine position was equivalent in all compression hosiery to the data defined in textile technology for compression class 2 (25–35 mmHg at the ankle). Compression hosiery produced a statistically significant improvement in venous refilling time t 0. The differing improvement in venous function could be explained by the quotient for maximum active pressure/resting pressure on standing (r = 0.98, p &lt;0.01). Conclusion: Compression stockings from the same compression class possess differing acute effects on venous haemodynamics. The efficacy of the various compression devices derives to an exceptional degree from the elasticity of the material, and can be characterised in vivo by the ratio between maximum pressure exerted during exercise and the resting pressure on standing.
Enantioselektive Gewinnung und Kristallstruktur des Ecstasy-Analogons N-Ethyl-3,4-methylendioxyamphetamin-HCl (MDE) und seiner beiden Hauptmetaboliten MDA und HME / Enantioselective Production and Crystal Structure of the Ecstasy Analogue N-Ethyl-3,4- methylenedioxyamphetamine-HCl (MDE) and its Major Metabolites MDA and HME
2000-12-01

A synthetic route to the production of the pure enantiomers of the ecstasy-analogue N-Ethyl- 3,4-methylenedioxyamphetamine (MDE) and its major metabolites MDA and HME is presented. The crystal and molecular structure of these compounds has been determined by X-ray crystallography. The hydrogen bonding in the crystal lattice is examined and significant differences were found by comparing (R)- and (S)-MDA-HCl.
Expression and Function of Na+HCO3− Cotransporters in the Gastrointestinal Tract
2000-12-01

A bstract : The stomach, duodenum, colon, and pancreas secrete HCO 3 − ions into the lumen. Although the importance of HCO 3 − secretion for the maintenance of mucosal integrity, a normal digestion, and the reabsorption of Cl − has been well established, the molecular nature of the apical and basolateral HCO 3 − transporting proteins has remained largely unknown. Functional studies have suggested that a Na + HCO 3 − cotransport system, similar but not identical to the well‐characterized Na + HCO 3 − cotransporter in the basolateral membrane of the kidney proximal tubule, is present in duodenal and colonic enterocytes, pancreatic ducts cells, and gastric cells and involved in HCO 3 − uptake from the interstitium. This report describes our work towards understanding the molecular nature, cellular origin, and functional relevance of the Na + HCO 3 − cotransporter(s) in the stomach and intestine and reviews work by others on the function and localization of Na + HCO 3 − cotransport processes in the gastrointestinal tract.
Three 5′‐Variant mRNAs of Anion Exchanger AE2 in Stomach and Intestine of Mouse, Rabbit, and Rat
2000-12-01

A bstract : AE2 is one of three known isoforms of the anion exchanger (AE) gene family. The use of alternative promoters, resulting in a tissue‐specific transcript pattern, was reported for all AE genes. Three N‐terminal variant AE2 subtypes are described: AE2a, AE2b, and AE2c. Although the basolaterally located parietal cell anion exchanger is known to be an AE2, the molecular identity of the basolateral and apical anion exchangers throughout the gut are still unknown. This article summarizes functional, immunohistochemical, and Western blot data demonstrating the basolateral localization of the gastric and intestinal AE2 in rabbit, mouse, and rat, and showing the AE2 subtype mRNA expression pattern in the stomach and along the intestine of rabbit and mouse: AE2a is expressed in all studied tissues, but most strongly in the colon; AE2b is expressed mainly in the stomach; and AE2c is detected nearly exclusively in the stomach. Further investigation is necessary to characterize the apical anion transport protein involved in NaCl absorption and HCO 3 − secretion in the gut.
A New Family Of Calcareous Microfossils From The Silurian Of Gotland, Sweden
2000-12-01

Scanning electron microscopy of polished, slightly etched rock surfaces of samples from the Silurian of Gotland, Sweden, revealed the presence of excellently preserved calcareous microfaunas and microfloras. This paper illustrates several morphotypes of calcareous micro‐organisms of unknown biological affinity, attributed to the new family Ovummuridae. Specimens of Ovummurus duoportius Minoura and Chitoku, a problematical microfossil, which was first described from the Upper Pennsylvanian of Kansas, USA, were found in addition to comparable micro‐organisms attributed to the following new taxa: Minourella gotlandica gen. et sp. nov., Arouxina pluricellata gen. et sp. nov. and Samtlebenella circumcamerata gen. et sp. nov. In addition, a few other problematical micro‐organisms, probably belonging to the same family, are described under open nomenclature. The enigmatic microfossils are compared with other known calcareous organisms, their possible biological affinities are discussed, and the different stages of diagenetic alteration and destruction are illustrated.
Interindividual variation of cerebral activation during encoding and retrieval of words
2000-12-01

The aim of the present study was to compare the cerebral activation associated with encoding and retrieval in individual subjects with the average activation in the same group of subjects. Twelve volunteers performed two paradigms: 1) intentional encoding of words, and 2) recognition of learned words intermixed with new distracters. Echo-planar magnetic resonance imaging (MRI) of BOLD signal changes was used to compare cerebral activation between active and resting conditions. During encoding, activation of the left precentral gyrus related to the motor response was observed in some subjects. Averaged data showed increased activation of the left precentral gyrus, the supplementary motor area (SMA), the left inferior frontal gyrus and in the left temporo-occipital junction. During recognition, motor response-related activity was found in the precentral cortex and SMA in most subjects. Activation in other brain areas showed considerable interindividual variation. In the entire group, recognition showed activation of the left dorsolateral prefrontal cortex, the precentral gyrus, the SMA, and the temporo-occipital junction. The total amount and the distribution of task-related cerebral activation varies considerably between individuals and might correspond to individual preferences of cognitive strategies. The investigation of these interindividual variations will be an exciting scientific challenge in the near future.
Investigative strategies and risk assessment of old unlined municipal solid waste landfills
2000-12-01

A case study was carried out at an old landfill site (Riet site) located in Winterthur, northern Switzerland. The Riet site contains mainly municipal solid wastes (MSW) comprising four discrete unlined landfill compartments, the oldest of which dates back to 1918. One goal of the case study was to assess the investigative techniques used to determine the risk of groundwater contamination. Waste compartments and leachate plumes were delineated with the electromagnetic method EM31 and with tracer methods. The most efficient methods for a risk assessment were flow modelling based on reliable hydraulic head and hydraulic conductivity measurements, and chemical analyses. Chemical analyses of leachate and groundwater samples showed that the older compartments of the landfill pose only a small risk to the groundwater. The other goal of the study was to determine the long-term risk of groundwater contamination posed by MSW landfills of different ages. To this end, chemical concentrations of leachate from the Riet site were compared with those of other MSW landfills of various ages. The long-term risk of landfill compartments older than about 1960 can be considered in general to be considerably smaller than that of younger ones. Age of the compartment and leachate concentrations could be correlated.
Contrasting effects of alloxan on islets and single mouse pancreatic β-cells
2000-12-01

Alloxan is used to induce diabetes in animals; however, the underlying mechanisms are still a matter of debate. Alloxan evoked a rapid hyperpolarization of the plasma membrane potential and suppressed electrical activity elicited by 15mM glucose, thus terminating voltage-dependent Ca2+ influx. Accordingly, glucose-induced oscillations in intracellular free Ca2+ concentration were abolished. The effect of alloxan on membrane potential could not be reversed by glucose but was reversed by tolbutamide. However, the sensitivity to tolbutamide was decreased after treatment of the cells with alloxan. These effects closely resemble those described earlier for H2O2. H2O2 and alloxan decreased the mitochondrial membrane potential, indicating a decrease in ATP production and thus interference with cell metabolism. A decrease in ATP synthesis would explain the plasma membrane hyperpolarization observed in intact islets, reflecting the activation of ATP-dependent K+ channels. Surprisingly, alloxan inhibited the whole-cell K+ATP current measured in single cells and the single-channel K+ATP current registered in excised patches. This inhibitory effect of alloxan is not mediated by changes in cell metabolism but seems to be due to direct interactions with the K+ATP channels via thiol-group oxidation. We have monitored the appearance of reactive oxygen species in single cells and islets treated with alloxan and H2O2 for comparison. In contrast to H2O2, alloxan induced the appearance of measurable reactive oxygen species only in islets but not in single cells. The results show that alloxan evokes different effects in islets and single cells, giving a possible explanation for inconsistent results reported in the past. It is concluded that alloxan exerts its diabetogenic effect by the production of H2O2 in intact islets.
Cyanophora paradoxa: Nucleotide Sequence and Phylogeny of the Nucleus Encoded Muroplast Fructose-1,6-bisphosphate Aldolase
2000-12-01

Immunoscreening of a C. paradoxa expression library against water soluble muroplast (“cyanelle”) proteins resulted in isolation of a clone encoding the nucleus-encoded muroplast class-II fructose-1,6-bisphosphate aldolase (class-II FBA § ). Its nucleotide sequence was determined. The 1432 bp insert, derived from a single-copy gene transcript, bears a reading frame of 1206 bp in length, representing 402 amino acids with 346 amino acids of mature protein. The leading amino acids match structural features necessary for precursor import across chloroplast envelope membranes. In phylogenetic tree topology, the investigated mature FBA clusters within type B FBAs with Synechocystis sp. as nearest neighbor. This is the first report of a Type B class-II FBA sequence of plastids.
Directions in Mathematical Quasicrystals
2000-12-05

Self-similar measures for quasicrystals by M. Baake and R. V. Moody Fourier analysis of deformed model sets by G. Bernuau and M. Duneau Mathematical quasicrystals and the problem of diffraction by J. C. Lagarias Designer quasicrystals: Cut-and-project sets with pre-assigned properties by P. A. B. Pleasants Generalized model sets and dynamical systems by M. Schlottmann On shelling icosahedral quasicrystals by A. Weiss Tilings, -algebras, and -theory by J. Kellendonk and I. F. Putnam Hulls of aperiodic solids and gap labeling theorems by J. Bellissard, D. J. L. Herrmann, and M. Zarrouati Quasicrystals, parametric density, and Wulff-shape by K. Boroczky, Jr., U. Schnell, and J. M. Wills Gordon-type arguments in the spectral theory of one-dimensional quasi-crystals by D. Damanik The planar dimer model with boundary: A survey by R. Kenyon Digit tiling of euclidean space by A. Vince A guide to quasicrystal literature by M. Baake and U. Grimm Index.
Self-similar measures for quasicrystals
2000-12-05

We study self-similar measures of Hutchinson type, defined by compact families of contractions, both in a single and multi-component setting. The results are applied in the context of general model sets to infer, via a generalized version of Weyl's Theorem on uniform distribution, the existence of invariant measures for families of self-similarities of regular model sets.
Dependence of the shell-model single-particle energies on different components of the nucleon-nucleon interaction
2000-12-05

The spin-orbit splittings in the spectra of nuclei with mass numbers 5, 15, and 17 are studied within the framework of shell-model configuration mixing calculations including excitations. The contributions of the two-body spin-orbit and tensor components of the nucleon-nucleon interaction are studied in various model spaces. It is found that the effects of the two-body spin-orbit interaction are dominant and quite sensitive to the size of the model space considered. The effects of the tensor interaction are weaker. The correlations effects which are included in the larger (0+2) shell-model space reduce the spin-orbit splitting in the case of by 20%, and enhance it for by about the same 20%. However, it is found that the correlations have a very small effect on the splitting in
Meeting Report: Plant Developmental Biologists Show Their Colors Toward a Virtual Understanding of Green DevelopmentA review of the meeting "Mechanisms in Plant Development", FASEB Summer Research Conference, Saxtons River, Vermont, 12 to 17 August 2000
2000-12-05

Schrick summarizes the advances made in understanding plant development presented at the FASEB Summer Research Conference, at which lessons learned from Arabidopsis were in the limelight. How the underlying mechanisms of plant development are similar to animal developmental pathways are highlighted.
Meeting Report: Plant Developmental Biologists Show Their Colors Toward a Virtual Understanding of Green Development
2000-12-05

Schrick summarizes the advances made in understanding plant development presented at the FASEB Summer Research Conference, at which lessons learned from Arabidopsis were in the limelight. How the underlying mechanisms of plant development are similar to animal developmental pathways are highlighted.
Intrinsic quadrupole moment of the nucleon
2000-12-08

We address the question of the intrinsic quadrupole moment Q_0 of the nucleon\\nin various models. All models give a positive intrinsic quadrupole moment for\\nthe proton. This corresponds to a prolate deformation. We also calculate the\\nintrinsic quadrupole moment of the Delta(1232). All our models lead to a\\nnegative intrinsic quadrupole moment of the Delta corresponding to an oblate\\ndeformation.\\n
MEK1 and Erk1/2 kinases as targets for the modulation of radiation responses.
2000-12-11

Since PD98059 did not alter radiation responses despite blocking MEK-1 kinase, MEK-1 and Erk1/2 are not involved in radiation resistance. Thus PD98059 has no potential in the modulation of radiation responses.
Oxidative stress in patients with Friedreich ataxia
2000-12-12

Increased generation of reactive oxygen species may underlie the pathophysiology of Friedreich ataxia (FRDA). The authors measured concentrations of 8-hydroxy-2'-deoxyguanosine (8OH2'dG), a marker of oxidative DNA damage, in urine and of dihydroxybenzoic acid (DHBA), a marker of hydroxyl radical attack, in plasma of 33 patients with FRDA. They found a 2.6-fold increase in normalized urinary 8OH2'dG but no change in plasma DHBA as compared with controls. Oral treatment with 5 mg/kg/day of the antioxidant idebenone for 8 weeks significantly decreased urinary 8OH2'dG concentrations, indicating that 8OH2'dG may be useful in monitoring therapeutic interventions in patients with FRDA.-1721
Effect of low-energy protons on the performance of the EPIC pn-CCD detector on XMM-Newton
2000-12-13

After the launch of Chandra, it was realized that low energy protons (below approximately 300 keV) are funnelled by grazing incident mirrors onto the focal plane detectors. Front illuminated CCD detectors are very sensitive to soft protons causing radiation damage in their electrode structures and transfer channels. The back-illuminated 280 micrometer thick fully depleted pn-CCD of the European Photon Imaging Camera (EPIC) on board the X-ray Multi Mirror mission (XMM) is by far less sensitive to low energy proton radiation. Commanding the camera in a special low gain mode, even allows to directly measure proton spectra and event patterns up to 300 keV per pixel. At the 3 MV Van-de-Graaff accelerator of the Institute for Physics in Tubingen we have irradiated and tested a 3 cm<SUP>2</SUP> flight-like pn-CCD with protons from 1 to 300 keV up to a fluence of 1.4 (DOT) 10<SUP>9</SUP> protons/cm<SUP>2</SUP>. This is about a factor of 1000 above the expected solar proton fluence for a 10 year XMM-Newton mission under nominal operational conditions. In this paper we given an overview of the proton irradiation experiment, discuss the performance of the detector after proton irradiation and finally present proton spectra directly measured with the pn-CCD on board XMM-Newton during solar flares. In addition, we briefly describe the precautionary measures taken to minimize the proton radiation dose of the EPIC CCD detectors in orbit.
In-orbit calibration activities of the XMM-Newton EPIC cameras
2000-12-13

The combined effective area of the three EPIC cameras of the XMM-Newton Observatory, offers the greatest collecting power ever deployed in an X-ray imaging system. The resulting potential for high sensitivity, broad-band spectroscopic investigations demands an accurate calibration. This work summarizes the initial in-orbit calibration activities that address these requirements. We highlight the first steps towards effective area determination, which includes the maintenance of gain CTI calibration to allow accurate energy determination. We discuss observations concerning the timing and count-rate capabilities of the detectors. Finally we note some performance implications of the optical blocking filters.
Protection by Synergistic Effects of Adenovirus-Mediated X-Chromosome-Linked Inhibitor of Apoptosis and Glial Cell Line-Derived Neurotrophic Factor Gene Transfer in the 1-Methyl-4-Phenyl-1,2,3,6-Tetrahydropyridine Model of Parkinson's Disease
2000-12-15

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) produces clinical, biochemical, and neuropathological changes reminiscent of those occurring in idiopathic Parkinson's disease (PD). Here we show that a peptide caspase inhibitor, N -benzyloxy-carbonyl-val-ala-asp-fluoromethyl ketone, or adenoviral gene transfer (AdV) of a protein caspase inhibitor, X-chromosome-linked inhibitor of apoptosis (XIAP), prevent cell death of dopaminergic substantia nigra pars compacta (SNpc) neurons induced by MPTP or its active metabolite 1-methyl-4-phenylpyridinium in vitro and in vivo . Because the MPTP-induced decrease in striatal concentrations of dopamine and its metabolites does not differ between AdV-XIAP- and control vector-treated mice, this protection is not associated with a preservation of nigrostriatal terminals. In contrast, the combination of adenoviral gene transfer of XIAP and of the glial cell line-derived neurotrophic factor to the striatum provides synergistic effects, rescuing dopaminergic SNpc neurons from cell death and maintaining their nigrostriatal terminals. These data suggest that a combination of a caspase inhibitor, which blocks death, and a neurotrophic factor, which promotes the specific function of the rescued neurons, may be a promising strategy for the treatment of PD.
Expression of AMPA receptor subunit flip/flop splice variants in the rat auditory brainstem and inferior colliculus
2000-12-21

The expression of alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionate (AMPA) receptor subunit mRNAs and their flip/flop splice variants was evaluated in the rat auditory brainstem and inferior colliculus employing in situ hybridization with radiolabeled oligonucleotide probes. A differential expression of AMPA receptor subunits in auditory nuclei was observed. In general, neurons in all nuclei of the auditory brainstem express high levels of GluR-C flop and GluR-D flop mRNA, but low to very low levels of GluR-A and GluR-B mRNA. The strongest GluR-C and -D flop expression is found in the ventral and medial part of the anteroventral cochlear nucleus, the posteroventral cochlear nucleus, and the medial and the lateral superior olive. These nuclei are part of the binaural auditory pathway which is important for sound localization in space. In contrast, neurons in the central nucleus of the inferior colliculus express high levels of GluR-B flip but only low levels of the other AMPA receptor subunits. From our data, we conclude that neurons of nuclei involved in binaural processing exhibit a specific "auditory AMPA receptor" which consists primarily of GluR-C flop and -D flop and often lacks GluR-B subunits; this indicates fast kinetics and high Ca(2+) permeability of AMPA receptor currents. In contrast, neurons in the central nucleus of the inferior colliculus contain large amounts of GluR-B flip subunits resulting in Ca(2+) impermeable AMPA receptors with slow kinetics.
Combined HPLC−MS and HPLC−NMR On-Line Coupling for the Separation and Determination of Lutein and Zeaxanthin Stereoisomers in Spinach and in Retina
2000-12-29

The determination and unambiguous identification of carotenoid stereoisomers from biological tissues, avoiding isomerization and oxidation due to the extraction process, is still a major challenge. Particularly, the analysis of lutein and zeaxanthin stereoisomers is of great importance, as these are the main constituents of the macula lutea, the central part of the human retina, and act as possible agents in the prevention and treatment of age-related macular degeneration (AMD). By combining a mild and quick extraction technique such as matrix solid-phase dispersion together with high-performance liquid chromatography (HPLC), the extremely light and oxygen sensitive lutein and zeaxanthin stereoisomers are extracted, enriched, and separated directly from the solid plant or tissue samples, excluding preparation of artifacts. HPLC separations are performed with C30 phases due to their enhanced shape selectivity compared to C18 phases and on-line coupled to mass spectrometry (MS) and nuclear magnetic resonance (NMR) spectroscopy. By using HPLC-MS with atmospheric pressure chemical ionization, the lutein stereoisomers can be distinguished from the zeaxanthin stereoisomers within one chromatographic run in the upper picogram range, whereas HPLC-NMR coupling allows the unequivocal identification of each stereoisomer with a concentration in the upper nanogram range. This article provides an analytical method for the artifact-free determination of lutein and zeaxanthin stereoisomers directly from the solid biological tissue spinach as a source of carotenoids and retina as the sphere of activity for AMD. In addition, the structures of these stereoisomers were unambiguously elucidated by employing hyphenated analytical techniques.