GLORIA

GEOMAR Library Ocean Research Information Access

feed icon rss

Ihre E-Mail wurde erfolgreich gesendet. Bitte prüfen Sie Ihren Maileingang.

Leider ist ein Fehler beim E-Mail-Versand aufgetreten. Bitte versuchen Sie es erneut.

Vorgang fortführen?

Exportieren
  • 1
    ISSN: 1077-3118
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: A projection optical system with 20:1 reduction has been used with radiation at ∼36 nm to evaluate resists for use in soft-x-ray projection lithography. The high absorption of soft x rays by carbon-based polymers requires that an imaging resist layer be very thin. The sensitivities and contrasts of several such resists are reported. By incorporating a thin imaging layer into a trilayer resist scheme, we have exposed, developed, and transferred features as small as 0.2 μm into silicon.
    Materialart: Digitale Medien
    Standort Signatur Einschränkungen Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 2
    ISSN: 1089-7623
    Quelle: AIP Digital Archive
    Thema: Physik , Elektrotechnik, Elektronik, Nachrichtentechnik
    Notizen: It has been shown that it is possible to produce near diffraction limited images with soft x rays of wavelength 13.8 nm using normal incidence Si/Mo-multilayered coated optics. Initial experiments with a 20X reduction Schwarzschild optic produced features as small as 50 nm. It is considered that soft x-ray projection lithography may be a likely candidate for the future generation of lithographic tools needed to produce 0.1-μm features for integrated circuits around the turn of the century.
    Materialart: Digitale Medien
    Standort Signatur Einschränkungen Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 3
    ISSN: 1432-0649
    Schlagwort(e): 68 ; 42.70 ; 42.60 ; 61.70 ; 61.50 ; 42.80 ; 29
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Physik
    Materialart: Digitale Medien
    Standort Signatur Einschränkungen Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 4
    Digitale Medien
    Digitale Medien
    Springer
    Diabetologia 33 (1990), S. 339-345 
    ISSN: 1432-0428
    Schlagwort(e): VLDL ; glycation ; triglyceride ; kinetics ; lipase ; rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Rat VLDL were glycated in vitro in the presence or absence of a reducing agent. Prior to glycation, the VLDL triglyceride was endogenously radiolabelled with [3H]-oleic acid. Post glycation the VLDL B-apoprotein was exogenously radiolabelled with [131]I. The double labelled VLDL was then injected into normal rats and the decline in plasma radioactivity of the two isotopes was used as a measure of triglyceride and particle clearance. VLDL glycated in either the presence or absence of reducing agent exhibited a significantly slower removal of triglyceride and apoprotein B compared to normal VLDL. The ability of glycated VLDL triglyceride to act as substrate for lipoprotein lipase and hepatic lipase was examined. Increasing concentrations of normal and glycated VLDL triglyceride were incubated with post-heparin plasma. The kinetics of triglyceride hydrolysis were determined in a manner analagous to Michaelis-Menten analysis. Glycated VLDL was found to be poorer than normal VLDL as a substrate for lipoprotein lipase. Glycation of VLDL appears to interfere with the lipolysis of its triglyceride. This may explain the delayed clearance of glycated VLDL triglyceride in vivo. Glycation also extended the mean plasma residence time of the VLDL particle. These factors may, in part, contribute to the hypertriglyceridaemia observed in subjects with diabetes mellitus.
    Materialart: Digitale Medien
    Standort Signatur Einschränkungen Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 5
    ISSN: 1619-7089
    Schlagwort(e): Key words: Vertebral metastases ; Bone scan ; Single-photon emission tomography ; Planar imaging
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract. Bone scan has long been considered to be an important diagnostic test in searching for bone metastases. However, considerable difficulty is encountered in the vertebral region due to the complexity of structures and the fact that other benign lesions, especially degenerative changes, are very common there. Single-photon emission tomography (SPET) has been reported to be useful in the differentiation of benign from malignant conditions. Here we report our experience with bone SPET in the diagnosis of vertebral metastases. This is a retrospective study of technetium-99m methylene diphosphonate (MDP) bone scans in 174 consecutive patients who were referred for the investigation of back pain in our department. MDP planar and SPET images were obtained. Of teh 174 patients, 98 had a known history of malignant tumours. The diagnosis of vertebral metastasis was made on the basis of the patients’ clinical histories and the findings with other imaging techniques such as magnetic resonance imaging, computed tomography or follow-up bone scan. We found that the presence of pedicle involvement as seen on SPET was an accurate diagnostic criterion of vertebral metastasis. SPET had a sensitivity of 87%, a specificity of 91%, a positive predictive value of 82%, a negative predictive value of 94% and an accuracy of 90%. On the other hand, planar study had a sensitivity of 74%, a specificity of 81%, a positive predictive value of 64%, a negative predictive value of 88% and an accuracy of 79% in diagnosing vertebral metastasis. Except with regard to the negative predictive value, SPET performed statistically better than planar imaging. Only 9/147 (6.4%) lesions involving the vertebral body alone and 3/49 (6.1%) lesions involving facet joints alone were subsequently found to be metastases. We conclude that bone SPET is an accurate diagnostic test for the detection of vertebral metastases and is superior to planar imaging in this respect.
    Materialart: Digitale Medien
    Standort Signatur Einschränkungen Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 6
    Publikationsdatum: 2013-11-14
    Beschreibung: Objective— Overproduction of hepatic apolipoprotein B (apoB)-100 containing very low-density lipoprotein particles and intestinal apoB-48 containing chylomicrons contributes to hypertriglyceridemia seen in conditions such as obesity and insulin resistance. Some, but not all, preclinical and clinical studies have demonstrated that the polyphenol resveratrol ameliorates insulin resistance and hypertriglyceridemia. Here, we assessed intestinal and hepatic lipoprotein turnover, in humans, after 2 weeks of treatment with resveratrol (1000 mg daily for week 1 followed by 2000 mg daily for week 2) or placebo. Approach and Results— Eight overweight or obese individuals with mild hypertriglyceridemia were studied on 2 occasions, 4 to 6 weeks apart, after treatment with resveratrol or placebo in a randomized, double-blinded, crossover study. Steady-state lipoprotein kinetics was assessed in a constant fed state with a primed, constant infusion of deuterated leucine. Resveratrol treatment did not significantly affect insulin sensitivity (homeostasis model of assessment of insulin resistance), fasting or fed plasma triglyceride concentration. Resveratrol reduced apoB-48 production rate by 22% ( P =0.007) with no significant effect on fractional catabolic rate. Resveratrol reduced apoB-100 production rate by 27% ( P =0.02) and fractional catabolic rate by 26% ( P =0.04). Conclusions— These results indicate that 2 weeks of high-dose resveratrol reduces intestinal and hepatic lipoprotein particle production. Long-term studies are needed to evaluate the potential clinical benefits of resveratrol in patients with hypertriglyceridemia, who have increased concentrations of triglyceride-rich lipoprotein apoB-100 and apoB-48. Clinical Trial Registration— URL: www.clinicaltrials.gov . Unique identifier: NCT01451918.
    Print ISSN: 1079-5642
    Digitale ISSN: 1524-4636
    Thema: Medizin
    Standort Signatur Einschränkungen Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 7
    Publikationsdatum: 2012-06-05
    Beschreibung: Objectives— Incretin-based therapies for the treatment of type 2 diabetes mellitus improve plasma lipid profiles and postprandial lipemia, but their exact mechanism of action remains unclear. Here, we examined the acute effect of the glucagon-like peptide-1 receptor agonist, exenatide, on intestinal and hepatic triglyceride-rich lipoprotein production and clearance in healthy humans. Methods and Results— Fifteen normolipidemic, normoglycemic men underwent 2 studies each (SC 10 μg exenatide versus placebo), 4 to 6 weeks apart, in random order, in which triglyceride-rich lipoprotein particle kinetics were examined with a primed, constant infusion of deuterated leucine and analyzed by multicompartmental modeling under pancreatic clamp conditions. A fed state was maintained during each study by infusing a high-fat, mixed macronutrient, liquid formula at a constant rate directly into the duodenum via a nasoduodenal tube. Exenatide significantly suppressed the plasma concentration and production rate of triglyceride-rich lipoprotein-apolipoprotein B-48, but not of triglyceride-rich lipoprotein-apolipoprotein B-100. Conclusions— These results suggest a possible direct effect of exenatide on intestinal lipoprotein particle production, independent of changes in weight gain and satiety as seen in long-term studies and independent of changes in gastric emptying. This finding expands our understanding of the effects of exenatide in metabolic regulation beyond its primary therapeutic role in regulation of glucose homeostasis. Clinical Trial Registration— URL: http://www.clinicaltrials.gov , NCT01056549.
    Schlagwort(e): Lipid and lipoprotein metabolism
    Print ISSN: 1079-5642
    Digitale ISSN: 1524-4636
    Thema: Medizin
    Standort Signatur Einschränkungen Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 8
    Publikationsdatum: 2015-03-27
    Beschreibung: Sodalis glossinidius is an intra- and extracellular symbiont of the tsetse fly ( Glossina sp.), which feeds exclusively on vertebrate blood. S. glossinidius resides in a wide variety of tsetse tissues and may encounter environments that differ dramatically in iron content. The Sodalis chromosome encodes a putative TonB-dependent outer membrane heme transporter (HemR) and a putative periplasmic/inner membrane ABC heme permease system (HemTUV). Because these gene products mediate iron acquisition processes by other enteric bacteria, we characterized their regulation and physiological role in the Sodalis /tsetse system. Our results show that the hemR and tonB genes are expressed by S. glossinidius in the tsetse fly. Furthermore, transcription of hemR in Sodalis is repressed in a high-iron environment by the iron-responsive transcriptional regulator Fur. Expression of the S. glossinidius hemR and hemTUV genes in an Escherichia coli strain unable to use heme as an iron source stimulated growth in the presence of heme or hemoglobin as the sole iron source. This stimulation was dependent on the presence of either the E. coli or Sodalis tonB gene. Sodalis tonB and hemR mutant strains were defective in their ability to colonize the gut of tsetse flies that lacked endogenous symbionts, while wild-type S. glossinidius proliferated in this same environment. Finally, we show that the Sodalis HemR protein is localized to the bacterial membrane and appears to bind hemin. Collectively, this study provides strong evidence that TonB-dependent, HemR-mediated iron acquisition is important for the maintenance of symbiont homeostasis in the tsetse fly, and it provides evidence for the expression of bacterial high-affinity iron acquisition genes in insect symbionts.
    Print ISSN: 0099-2240
    Digitale ISSN: 1098-5336
    Thema: Biologie
    Standort Signatur Einschränkungen Verfügbarkeit
    BibTip Andere fanden auch interessant ...
Schließen ⊗
Diese Webseite nutzt Cookies und das Analyse-Tool Matomo. Weitere Informationen finden Sie hier...