Sökresultat

Filtyp

Din sökning på "*" gav 536332 sökträffar

DT Modeling of Clock Phase Noise Effects in LP CT Delta-Sigma ADCs with RZ Feedback

The performance of continuous-time (CT) Delta Sigma modulators is limited by their sensitivity to clock phase noise (PN). The clock PN-induced in-band noise (IBN) is dependent on the magnitude and frequency of both the desired in-band signals and the out-of-band signals, as well as the shape of the clock PN spectrum. This brief presents a discrete-time (DT) model of the dominant clock PN-induced e

Identification of 20 polymorphic microsatellite loci in European crow (Corvus corone) from existing passerine loci

The European crow (Corvus corone) occurs in two subspecies (or species) with distinct plumage coloration: the black carrion crow (C. c. corone) and the grey and black hooded crow (C. c. cornix). We tested 42 passerine microsatellite loci for amplification in the European crow and identified 20 loci that were both polymorphic and easy to score. In 50 individuals sampled in the Danish part of the sp

Polyelectrolyte-surfactant complexes with long range order.

Mixtures of carboxymethyl cellulose (CMC) or hydrophobically modified CMC with an oppositely charged surfactant (benzyldimethyltetradecylammonium chloride) in water were prepared. When the global polymer concentration is 0.18% by weight and the surfactant content is high enough, a precipitate with hexagonal order is formed. The precipitate composition shows practically constancy in its water conte

Efficacy of Bioactive Polypeptides on Bleeding and Intra-Abdominal Adhesions.

Background: Perioperative bleeding and postoperative adhesions are two problems encountered in abdominal surgery. Commercial products are available that decrease both bleeding and development of abdominal adhesions, but no products are effective in both situations. The combination of differently charged bioactive polypeptides, administered intraperitoneally, has previously been shown effective in

The 80th anniversary of von Willebrand's disease: history, management and research

The history of von Willebrand's disease (VWD) is fascinating because it demonstrates how good clinical observations, genetic studies and biochemical skills can improve basic understanding of a disease and its management. The continuous efforts of scientists and clinicians during the last 80 years have significantly improved the knowledge of von Willebrand factor (VWF) structure and function and th

Two novel cyclodextrin-degrading enzymes isolated from thermophilic bacteria have similar domain structures but differ in oligomeric state and activity profile

In this paper, we present the expression and characterization of two novel enzymes from the a-amylase family exhibiting cyclomaltodextrinase specificity. The nucleotide sequences encoding the enzymes were isolated from the genomic DNA of two thermophilic bacterial strains originating from Icelandic hot springs and belonging to the genera Anoxybacillus (AfCda13) and Laceyella (LsCda13). The genes w

Formation of amylose-lipid complexes and effects of temperature treatment. Part 1: Monoglycerides.

The formation of amylose-lipid complexes of form I (amorphous structure) and form II (crystalline structure) during heating was studied by differential scanning calorimetry (DSC) for a range of monoglycerides and for monoglyceride mixtures. The temperature treatment applied to amylose-monoglyceride-mixtures were either the first scan in DSC (10 °C/min, 15-144 °C) or a prolonged heat treatment wher

Transanastomotic feeding tube after an operation for duodenal atresia.

The aim of this study was to answer the question whether or not, after an operation for duodenal atresia, a transanastomotic feeding tube reduces the time to full preanastomotic feeding. The method used was a retrospective study and a prospective observation. 18 consecutive newborns with duodenal atresia, nine from each of two different centres of paediatric surgery, were studied retrospectively.

Fa-brication and characterization of a molecular adhesive layer for micro- and nanofabricated electrochemical electrodes

In the microelectronics industry, gold electrodes on silicon dioxide are produced using an adhesive layer of chromium or titanium. This method is applicable whenever a dry environment is present. However, when such an electrode is exposed to an electrolyte a galvanic cell is formed and the less noble metal will dissolve and eventually destroy the electrode. We describe here how a monolayer of merc

Spin filtering in single magnetic barrier structures revisited

We reexamine spin-dependent transport properties of two-dimensional electrons modulated by the stray field of a ferromagnetic metal (FM) stripe on top. When the magnetization is along the transport direction of the electrons, the FM stripe generates not only a magnetic barrier but also an in-plane magnetic field component. Previous studies have omitted the in-plane magnetic field component and sho

Echocardiographic and electrocardiographic identification of those children with hypertrophic cardiomyopathy who should be considered at high-risk of dying suddenly

Background., Hypertrophic cardiomyopathy is a common cause of sudden death in children. In this study, we aimed to identify clinical measures for stratification of this risk in childhood. Patients and methods: By means of a retrospective cohort study from six regional centres of paediatric cardiology, we identified 128 patients with hypertrophic cardiomyopathy presenting below 19 years of age, wit

Influence of chemical bonds on the lifetime of the molecular-field-split 2p levels in H2S

Different lifetime broadenings in molecular-field-split 2p core levels in H2S are predicted theoretically and are identified in an experimental investigation of the S 2p Auger electron spectrum. The measurements were performed for the transition to the vibrationally resolved X(1)A(1) ground state of H2S2+. The lifetimes of the 3e(1/2) and 5e(1/2) levels of the 2p ionized molecule are found to be 6

Lactotetraosylceramide, a novel glycosphingolipid receptor for Helicobacter pylori, present in human gastric epithelium

The binding of Helicobacter pylori to glycosphingolipids was examined by binding of 35S-labeled bacteria to glycosphingolipids on thin-layer chromatograms. In addition to previously reported binding specificities, a selective binding to a non-acid tetraglycosylceramide of human meconium was found. This H. pylori binding glycosphingolipid was isolated and, on the basis of mass spectrometry, proton

Collagen VI glycine mutations: Perturbed assembly and a spectrum of clinical severity

Objective: The collagen VI muscular dystrophies, Bethlem myopathy and Ullrich congenital muscular dystrophy, form a continuum of clinical phenotypes. Glycine mutations in the triple helix have been identified in both Bethlem and Ullrich congenital muscular dystrophy, but it is not known why they cause these different phenotypes. Methods: We studied eight new patients who presented with a spectrum

End-of-life decision making in Europe and Australia - A physician survey

Background: The frequencies with which physicians make different medical end-of-life decisions (ELDs) may differ between countries, but comparison between countries has been difficult owing to the use of dissimilar research methods. Methods: A written questionnaire was sent to a random sample of physicians from 9 specialties in 6 European countries and Australia to investigate possible differences

Scintillation proximity assay using molecularly imprinted microspheres.

Molecularly imprinted microspheres were prepared as antibody binding mimics and used in scintillation proximity assay of a beta-adrenergic antagonist, (S)-propranolol. By using small polymer beads, we were able to place an organic scintillator and an "antenna" component in close proximity to the imprinted binding sites. When the radioactive template bound to the polymer, radiation energy was effec

Ex vivo gene delivery of GDNF using primary astrocytes transduced with a lentiviral vector provides neuroprotection in a rat model of Parkinson's disease.

Astrocytes are, as normal constituents of the brain, promising vehicles for ex vivo gene delivery to the central nervous system. In the present study, we have used a lentiviral vector encoding glial cell line-derived neurotrophic factor (GDNF) to transduce rat-derived primary astrocytes, in order to evaluate their potential for long-term transgene expression in vivo and neuroprotection in a rat mo