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91.
We set out to determine whether advanced epithelial ovarian cancer (EOC) is associated with elevated serum and ascitic concentrations of the angiogenic factors angiogenin (ANG), basic fibroblastic growth factor (bFGF), and vascular endothelial growth factor (VEGF), and whether the expression of angiogenic factors was associated with tumor vascularity. Serum and ascitic samples were collected from previously untreated patients with FIGO stage III and IV EOC and stored at -70 degreesC. Levels of the three factors were determined by enzyme-linked immunoassay. Histological sections from paraffin blocks of ovarian cancers were stained immunochemically for factor VIII, CD34, and VEGF. Thirty-nine patients were studied, although not all had paired serum and ascitic samples. For each angiogenic factor, the following findings were noted: (a) there was a wide range in serum and ascitic fluid concentrations; (b) the mean serum concentration was higher (P < 0.05) than the mean concentration in normal serum; and (c) the mean serum concentration was lower (P < 0. 05) than the mean ascitic concentration. Overall, the most consistent pattern of elevated serum and ascitic concentrations was with bFGF. With serum samples, 38.9% of patients had a normal VEGF concentration, as did 15.3% for ANG and 7.7% for bFGF. In ascites, the VEGF concentration was in the range for normal serum in 24.5% of samples, compared to 39.4% for ANG and 2.8% for bFGF. In paired samples, both VEGF and bFGF showed higher ascitic concentrations in 100 and 88.3% of samples, compared to 53.3% for ANG. There was no correlation between the serum and/or ascitic concentration of one factor and that of another, suggesting that these factors are independently regulated. Staining with anti-CD34 was more sensitive and reliable than with anti-factor VIII. VEGF staining was most prominent in poorly differentiated tumors and was observed only on tumor cells. There was no correlation between the serum or ascitic concentrations of angiogenic factors and tumor vascularity. Advanced EOC is associated with raised serum and ascitic bFGF concentrations and with markedly elevated ascitic VEGF in most cases. Serum VEGF and serum and ascitic ANG are less often elevated. There was no correlation between the angiogenic profile in serum and ascites and tumor vascularity.  相似文献   
92.
Glass-ceramic bonding in alumina/CBN abrasive systems   总被引:2,自引:0,他引:2  
A glass-ceramic bond which can be applied in alumina/CBN abrasive systems was developed by the method of liquid-phase sintering of a homogenized mixture of alumina abrasives and bonding medium containing various amounts of B2O3. Microstructural and mechanical examinations have shown that the amount of B2O3 present in the starting glass frit determines the ultimate properties of the glass-ceramic bond which can be successfully used in the Al2O2/CBN abrasive systems.  相似文献   
93.
The biocompatibility of contact lenses is closely related to their oxygen permeability. In hydrogel lenses, this characteristic can be attributed to the water permeability resulting from a combination of viscous and diffusive fluxes. Hydrogel lenses were studied by means of nuclear magnetic resonance (NMR) relaxation times, resulting in a mathematical model which evaluated the water self-diffusion coefficient as a quantification of the diffusive contribution to permeation. Comparing the results obtained with the data of permeability to oxygen as measured by other techniques, a reasonable agreement was shown for lenses with a higher water content (WC) with respect to lenses with a lower WC: this difference was accounted for by considering the different contribution to permeation.  相似文献   
94.

Abstract  

In the present work, we investigated the scattering and spectrally resolved absorption properties of nanofluids consisting in aqueous and glycol suspensions of single-wall carbon nanohorns. The characteristics of these nanofluids were evaluated in view of their use as sunlight absorber fluids in a solar device. The observed nanoparticle-induced differences in optical properties appeared promising, leading to a considerably higher sunlight absorption with respect to the pure base fluids. Scattered light was found to be not more than about 5% with respect to the total attenuation of light. Both these effects, together with the possible chemical functionalization of carbon nanohorns, make this new kind of nanofluids very interesting for increasing the overall efficiency of the sunlight exploiting device.  相似文献   
95.
The involvement of the serotonin 5‐HT1A receptor (5‐HT1A‐R) in the antidepressant effect of allyphenyline and its analogues indicates that ligands bearing the 2‐substituted imidazoline nucleus as a structural motif interact with 5‐HT1A‐R. Therefore, we examined the 5‐HT1A‐R profile of several imidazoline molecules endowed with a common scaffold consisting of an aromatic moiety linked to the 2‐position of an imidazoline nucleus by a biatomic bridge. Our aim was to discover other ligands targeting 5‐HT1A‐R and to identify the structural features favoring 5‐HT1A‐R interaction. Structure–activity relationships, supported by modeling studies, suggested that some structural cliché such as a polar function and a methyl group in the bridge, as well as proper steric hindrance in the aromatic area of the above scaffold, favored 5‐HT1A‐R recognition and activation. We also highlighted the potent antidepressant‐like effect (mouse forced swimming test) of (S)‐(+)‐ 19 [(S)‐(+)‐naphtyline] at very low dose (0.01 mg kg?1). This effect was clearly mediated by 5‐HT1A, as it was significantly reduced by pretreatment with the 5‐HT1A antagonist WAY100635.  相似文献   
96.
Observers of patch-light videotape displays can reliably discriminate levels of lifted weight; accuracy of judgments sometimes approximates that achieved when the observers themselves lift weighted boxes. Results of 6 studies reveal impressive levels of visual weight discrimination based on static displays (photographs) of certain action phases sampled from videos of entire lifting-carrying events. Slow and controlled actions (e.g., walking, placing box on table) supported optimum weight discrimination for both photographic and video displays, whereas the action of lifting a box yielded high levels of discrimination only for video displays. Static and kinematic specification of dynamics, as well as the work by painters and photographers to depict humans and other animals in action, is discussed.  相似文献   
97.
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99.
ABSTRACT

A microprocessor system for automatic electroanalytical determinations is described. Application to potentiometric titrations according to Gran's method is dicussed. The results obtained by suitably designed procedures point to good analytical reliability.  相似文献   
100.
A power unit constituted by a reformer section, a H2 purification section and a fuel cell stack is being tested c/o the Dept. of Physical Chemistry and Electrochemistry of Università degli Studi di Milano, on the basis of a collaboration with HELBIO S.A. Hydrogen and Energy Production Systems, Patras (Greece), supplier of the unit, and some sponsors (Linea Energia S.p.A., Parco Tecnologico Padano and Provincia di Lodi, Italy). The system size allows to co-generate 5 kWe (220 V, 50 Hz a.c.) + 5 kWt (hot water at 65 °C) as peak output. Bioethanol, obtainable by different non-food-competitive biomass, is transformed into syngas by a pre-reforming and reforming reactors couple and the reformate is purified from CO to a concentration below 20 ppmv, suitable to feed a proton exchange membrane fuel cell (PEMFC) stack that will be integrated in the fuel processor in a second step of the experimentation. This result is achieved by feeding the reformate to two water gas shift reactors, connected in series and operating at high and low temperature, respectively. CO concentration in the outcoming gas is ca. 0.4 vol% and the final CO removal to meet the specifications is accomplished by two methanation reactors in series. The second methanation step acts merely as a guard, since ca. 15 ppmv of CO are obtained already after the first reactor.  相似文献   
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