Library

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    ISSN: 1432-0428
    Keywords: Lipoproteins ; VLDL subfractions ; diabetes mellitus ; lipid composition ; lipolytic enzymes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Very low density lipoproteins (VLDL) have an abnormal lipid composition in Type 1 (insulin-dependent) diabetic patients. Since VLDL represent a heterogeneous lipoprotein class, this might be due either to a shift in the distribution or to an abnormal composition of VLDL subclasses or both. In order to investigate these possibilities and to evaluate possible pathogenetic mechanisms, lipid composition (non-esterified and esterified cholesterol, triglycerides, phospholipids) of four VLDL subfractions of decreasing size (A: Svedberg flotation unit [Sf]〉400, B: Sf, 175–400, C: Sf 100–175, D: Sf 20–100), isolated by density gradient preparative ultracentrifugation, and plasma post-heparin lipolytic activity (lipoprotein lipase and hepatic lipase) were evaluated in 13 male normolipidaemic insulin-dependent diabetic patients in good glycaemic control (HbA1c 6.9±0.5%) (mean±SEM) and 9 male control subjects matched for age, body mass index and plasma lipid values. Compared to control subjects, diabetic patients showed a reduced total lipid concentration of VLDL of intermediate size (B and C) reaching statistical significance only for VLDL C (0.16±0.02 vs 0.24±0.03 mmol/l; p 〈0.05). Expressing each VLDL subfraction as percent of the total VLDL lipid concentration, a significant decrease in particles of intermediate size (C) (20.5±1.6 vs 27.9±1.5%; p 〈0.005) was present, which was compensated by an increase in the smallest ones (D) (50.5±2.7 vs 37.4±3.1%; p 〈0.05). VLDL of smaller size were also the only particles with an abnormal composition consisting of a significant increase in esterified cholesterol (12.2±0.8 vs 8.7±1.2%, p 〈0.01). Post-heparin hepatic lipase activity was significantly reduced in diabetic patients as compared to control subjects (232.9±27.9 vs 332±42.3 mU/ml; p 〈0.05) while post-heparin lipoprotein lipase activity was similar in the two groups. Furthermore, hepatic lipase activity was inversely related to the percentage of smaller VLDL (D)(r=−0.72; p 〈0.01) in diabetic patients and this relationship was independent of changes in intermediate VLDL (VLDL C). In conclusion the data suggest that Type 1 diabetic patients, although normolipidaemic and in good blood glucose control, show a shift in the distribution of VLDL subclasses toward VLDL of a smaller size which also have an abnormal composition. The different distribution of VLDL subfractions seems to be related to a reduced hepatic lipase activity.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    s.l. : American Chemical Society
    Journal of medicinal chemistry 33 (1990), S. 1470-1476 
    ISSN: 1520-4804
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Colloid & polymer science 268 (1990), S. 720-725 
    ISSN: 1435-1536
    Keywords: Syndiotacticpolystyrene ; drawingbehavior ; influence ofdrawing andtemperature ; elasticmodulus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract The drawing behavior of syndiotactic polystyrene was analyzed at different temperatures. Amorphous films were used and, depending on drawing temperature, strain-induced or thermal-induced cold crystallization was observed. This phenomenon, when present, greatly affects the drawing behavior. The dynamic-mechanical behavior of drawn samples was analyzed, and the obtained results indicate that the glass transition is affected by drawing, and that the effect depends drastically on the drawing temperature. Particularly interesting is the dynamic behavior at high temperature where the elastic modulus is weakly affected by temperature also near the melting point.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Experiments in fluids 11 (1991), S. 351-358 
    ISSN: 1432-1114
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract A new configuration for the transmitting optics of a laser Doppler anemometer has been developed in order to measure the velocity at two different points at the same time. From the simultaneous measurements at two points along the mean flow direction it is possible to evaluate the spatial correlations and to compare them with the temporal correlation to verify the validity limits of Taylor's hypothesis also known as the frozen turbulence hypothesis. The transfer function between the velocity signals at two different points has been introduced to better explain the differences between Taylor's hypothesis and non frozen flow. The analysis is carried out in a flow with high turbulence levels.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Colloid & polymer science 268 (1990), S. 625-629 
    ISSN: 1435-1536
    Keywords: Isotacticpolypropylene cross-linked ; drawing behavior:crystallinity ; structural andtopological features ; yielding,necking phenomena,ultimate properties
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract The drawing behavior of cross-linked isotactic polypropylene was analysed. The crystallinity and the composition of the crystalline phase are affected by cross-linking. Structural and topological features play a significant role in the drawing behavior. The yielding, the necking phenomenon, and the ultimate properties, i.e., stress and strain at the fracture, can be correlated with the sample structure. The general picture agrees well with Peterlin's model of cold drawing.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Colloid & polymer science 271 (1993), S. 454-459 
    ISSN: 1435-1536
    Keywords: Syndiotactic polystyrene ; polymorphism ; phase transitions ; dynamic behavior
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract The syndiotactic polystyrene can crystallize in different forms, depending on thermal and solvent treatments. The influence of the polymorphism on the dynamic-mechanical behavior has been analyzed. Thermogravimetric and calorimetric analysis were also carried out. The effects of phase transitions and solvent release on the relaxation phenomena were observed, and the correlations between structure and dynamic behavior allow to better understand some aspects of the polymorphism phenomena.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 7
    ISSN: 1530-0358
    Keywords: Rectal cancer ; Local recurrence ; Imaging techniques
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The use of modern techniques of imaging in the postoperative follow-up is reported to allow an earlier diagnosis of local recurrence in patients operated on with anterior resection for rectal cancer and, consequently, to allow a higher percentage of local recurrence resection to be performed. Although intrarectal ultrasound (IU) has proved highly reliable in preoperative staging, its value in relapse detection has been investigated only in retrospective studies and rarely compared with that of computed tomography (CT). The present prospective study aims at evaluating the role of IUvs. CT in the diagnosis of local recurrence and at verifying whether an earlier diagnosis and a higher resectability rate of recurrence result in an acceptable long-term survival. Thirty-seven patients who had undergone low and ultralow anterior resection for rectal cancer (anastomosis within 10 cm of the anal verge) were investigated prospectively. All the patients have been followed up by IU and CT at predetermined intervals. Six local recurrences were detected. CT correctly identified all the local recurrences (sensitivity = 100 percent, specificity = 93 percent, and accuracy = 94.5 percent); IU correctly identified only four of six local recurrences (sensitivity = 66.6 percent, specificity = 93 percent, and accuracy = 89 percent). Four patients with local recurrence underwent surgical treatment (resectability rate = 66.6 percent). Abdominoperineal resection in three patients and Hartmann's procedure in one patient were performed. In the other two patients, extensive metastatic liver involvements contraindicated surgery. All the resected patients were alive after one year; two of them are disease free, and the other two experienced recurrent disease. In conclusion, CT seems to have a higher sensitivity and accuracy in relapse detection. The increase in the local recurrence resectability rate does not result in a significant improvement in longterm survival. However, the good quality of life justifies the high cost of an intensive follow-up and a more aggressive surgical approach.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 8
    Electronic Resource
    Electronic Resource
    Brookfield, Conn. : Wiley-Blackwell
    Polymer Composites 11 (1990), S. 1-9 
    ISSN: 0272-8397
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: The behavior of poly(ethylene terephthalate) (PET) and poly(butylene terephthalate) (PBT) on water aging has been studied above and below the glass transition temperature (Tg). The aging process is caused by: degradation of the matrix and an increase in crystallinity above Tg, and microcavitation at the amorphous/crystalline interface below Tg. Such behavior well explains the deviation of the sorption kinetics from the Fickian model. The apparent water diffusion coefficients and the transport activation energies of PET and PBT have been calculated at temperatures above and below Tg. The mechanical behavior of the two polymers on water aging has been measured by means of fracture mechanics and Izod impact tests at different stress concentration factors. An increase of toughness of PET at short aging times has been shown by mechanical tests and SEM analysis fracture surfaces of differently aged samples. Izod tests of PET and PBT composites reinforced by long glass fibers have shown the contribution of fibers to the total fracture energy.
    Additional Material: 16 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 9
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 46 (1992), S. 1799-1806 
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Fibers of isotactic polypropylene were obtained by high-temperature drawing, adopting a two-stage process. Very high drawing degrees were achieved, more than 40. The physical behavior was analyzed by determining the dynamic-mechanical relaxation spectra in monoaxial stretching. The results obtained show that the elastic modulus reaches a saturation value at deformation degrees of about 20, well below the drawability upper limit, indicating that above 20 any further drawing does not affect the structure. Moreover the α transition appears weak or absent in the drawn samples, while the β transition is still readily detectable. Both effects agree with Peterlin's model of drawing and with the fiber structure. © 1992 John Wiley & Sons, Inc.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...