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51.
Recently, we have demonstrated that a spectrum of human adenocarcinoma cell lines express binding sites for interleukin 13 (IL-13). These cells are killed by a chimeric protein composed of human (h) IL-13 and a derivative of Pseudomonas exotoxin, PE38QQR (Debinski et al., J. Biol. Chem., 270: 16775-16780, 1995). The cell killing was hIL-13- and hIL-4-specific, indicating that a common binding site for the two cytokines is present in several solid tumor cell lines. Herein, we report that an array of established glioma cell lines is killed by very low concentrations of hIL-13-PE38QQR, often reaching <1 ng/ml (<20 pM). Glioma cells express up to 30,000 molecules of IL-13 receptor/cell which has intermediate affinity toward hIL-13. hIL-13-PE38QQR is more active (up to 3 logs difference in cytotoxic activities) than are the corresponding chimeric toxins containing hIL-4 or hIL-6. The cytotoxic action of hIL-13-PE38QQR is blocked by an excess of hIL-13 on all cell lines studied, and it is not neutralized by hIL-4 on some of these cells. Our results show that human brain cancers richly express receptors for IL-13. Furthermore, the interaction detected previously between receptors for IL-13 and IL-4 on solid tumors cell lines is of a qualitatively different character in U-251 MG and U-373 MG glioma cells. The receptor for IL-13 may represent a new marker of brain cancers and an attractive target for anticancer therapies.  相似文献   
52.
Data on 1,000 pairs of sisters from the National Longitudinal Survey of Youth are used to estimate the effects of observed individual-level factors, common family-level variables, and shared unobserved family-level traits on the timing of premarital births. Results show a moderate correlated risk of premarital childbearing among siblings after controlling for the effects of measured covariates. The effect of older sisters' out-of-wedlock childbearing on the timing of younger sisters' premarital birth is overestimated when shared unmeasured family-level traits are ignored. Public policy measures designed to reduce premarital births have a smaller multiplier effect via reduced younger sisters' premarital births because unmeasured family-level factors are less amenable to policy measures. However, because the older-sibling effect is large when other sources of variability in premarital birth timing are controlled, interventions may be effective in reducing premarital births among young women in high-risk families.  相似文献   
53.
Molybdenum‐doped cordierite ceramics have been fabricated through facile combined techniques, coprecipitation followed by solid state. XRD results revealed that α‐cordierite phase is predominated with increasing Mo6+ ion content. The density measurements showed that the bulk density reduced to the minimum value of 0.61 g/cm3, which corresponds to the maximum porosity of about 76.8% at 5% Mo6+ ion. The dielectric permittivity (ε) of pure cordierite is decreased with increasing Mo6+ ion content. The minimum dielectric loss of Mo‐doped cordierite at 1 MHz was equal 0.008 with 10% Mo6+, while at 1 GHz was equal 0.03 with 5% Mo6+.  相似文献   
54.
The structure of a two-phase steady detonation in a granulated solid propellant studied, and existence conditions for a one-dimensional, steady two-phase detonation are given. Ordinary differential equations from continuum mixture theory are solved numerically to determine steady wave structure. In the limiting case where heat transfer and compaction effects are negligible, the model reduces to two ordinary differential equations that have a clear geometrical interpretation in a two-dimensional phase plane. This two-equation model predicts results that are quite similar to those of the full model. This suggests that in the limited parameter space studied heat transfer and compaction are not important mechanisms in determining the detonation structure. It is found that strong and Chapman-Jouguet (CJ) detonation solutions with a leading gas phase shock and unshocked solid can be admitted, as can weak and CJ solutions with an unshocked gas and solid. As for one-phase materials, the CJ wave speed is the speed of propagation predicted for an unsupported, one-dimensional, two-phase detonation. It is predicted that there is no admissible CJ structure with a single leading gas phase shock and unshocked solid below a critical value of initial bulk density. This result cannot be predicted from equilibrium end state analysis. Thus it is concluded that it is essential to consider reaction zone structure when assissing potential solutions.  相似文献   
55.
The effectiveness of in situ treatment using zero-valent iron (ZVI) for nonaqueous phase or significant sediment-associated contaminant mass can be limited by relatively low rates of mass transfer to bring contaminants in contact with the reactive media. For a field test in a trichloroethene (TCE) source area, combining moderate-temperature subsurface electrical resistance heating with in situ ZVI treatment was shown to accelerate TCE treatment by a factor of about 4 based on organic daughter products and a factor about 8 based on chloride concentrations. A mass-discharge-based analysis was used to evaluate reaction, dissolution, and volatilization processes at ambient groundwater temperature (~10 °C) and as temperature was increased up to about 50 °C. Increased reaction and contaminant dissolution were observed with increased temperature, but vapor- or aqueous-phase migration of TCE out of the treatment zone was minimal during the test because reactions maintained low aqueous-phase TCE concentrations.  相似文献   
56.
Abstract: Foods with antioxidant capacity provide protection against cardio‐vascular, certain forms of cancers, and Alzheimer's diseases caused by oxidative damages and contribute health benefits. The effect of extrusion cooking on the antioxidant capacity and color attributes of extruded products prepared from 3 selected formulations of purple potato and yellow pea flours using a co‐rotating twin screw extruder were studied. Expansion ratios of the extruded products varied from 3.93 to 4.75. The total antioxidant capacities (TAC) of the extruded products, using DPPH assay, were 3769 to 4116 μg trolox equivalent/g dry weight sample and not significantly different (P > 0.05) from their respective raw formulations. The total phenolic contents (TP) of the extruded products varied from 2088 to 3766 μg of gallic acid equivalent/g dry weight sample and retained 73% to 83% of the TP from the raw formulations after extrusion. The total anthocyanins contents (TA) in the extrudates were 0.116 to 0.228 mg of malvidin‐3‐glucosides/g dry weight sample. Compared with their raw formulations, significant losses (60% to 70%) of the TA in the extruded products occurred due to extrusion cooking. Browning indices and color attributes such as brightness, chroma, and hue angle agreed with degradation of anthocyanins in the extruded products. However, extrusion cooking retained antioxidant capacities of the raw formulations in the extruded products either in their natural forms or degraded products with radical scavenging activity. This study demonstrated the potential for the production of puffed extruded food products with the improved antioxidant content from colored potatoes and pulse formulations.  相似文献   
57.
Thymoma in dogs: 23 cases (1980-1991)   总被引:1,自引:0,他引:1  
OBJECTIVE: To assess the efficacy of misoprostol for the treatment of chronic erosive gastritis and associated symptoms. METHODS: We performed a double-blind controlled trial, administering 200-micrograms misoprostol tablets or placebo twice daily for 2 months to 48 patients with symptomatic chronic erosive gastritis. Symptomatology was assessed by means of a standard questionnaire at the beginning and at the end of the study, as well as endoscopic and histologic changes of the gastric mucosa. RESULTS: At the end of the treatment period, a significant reduction in symptom score was observed in misoprostol-treated (from 86.6 +/- 66.2 to 17.6 +/- 18.2, p < 0.001) but not in placebo-treated patients. Endoscopic score was significantly reduced at the end of the treatment period in the misoprostol group, compared with that of the placebo group (p < 0.05). A significant reduction in the activity of histologic gastritis was observed only in patients on misoprostol. The prevalence of gastric colonization by Helicobacter pylori was rather low (30%), and no effect of treatment was observed. CONCLUSIONS: Patients with symptomatic chronic erosive gastritis seem to profit from treatment with misoprostol: the treatment with misoprostol, but not with placebo, was effective in significantly reducing the extent of symptoms. Such an improvement was associated with a substantial improvement in the endoscopic and histologic appearance of the gastric mucosa.  相似文献   
58.
Controlled-geometry voids were introduced into unim-planted and Ti-implanted high-purity c -axis sapphire substrates using microfabrication techniques and ion beam etching, and subsequently transferred to an internal interface by hot-pressing. The morphological evolution of crack-like and channellike defects oriented parallel to the basal plane in response to anneals at 1700°C was studied. The healing behavior of defects in the unimplanted and Ti-ion-implanted samples differs significantly. Ti additions appear to reverse the directional dependence of the healing characteristics in undoped sapphire, greatly stabilizing defects with edges aligned along the [1100] direction, while reducing the stability of defects with edges aligned parallel to the [1120] direction relative to unimplanted sapphire. The healing characteristics of unimplanted and Ti-implanted sapphire substrates are compared and contrasted with those observed previously in Ca- and Mg-ion-implanted sapphire.  相似文献   
59.
When a rigorous methodological approach is utilized, a substantial majority of recent studies provide evidence for the familial transmission of schizophrenia. Although the absolute rates of schizophrenia among relatives of schizophrenics tend to be lower than those reported in the earlier studies due to the restrictiveness of contemporary definitions of schizophrenia, the risk to relatives compared to that of controls has remained quite consistent. This observation that relatives of schizophrenics have an elevated risk for schizophrenia compared to controls is consistent with theories of both genetic and environmental transmission. Twin studies of schizophrenia have consistently reported greater concordance rates for monozygotic than dizygotic twins. Although this indicates the importance of genetic factors, the less than 100% concordance for monozygotic twins observed in every study indicates that nongenetic factors also play a role in the etiology of schizophrenia. Further, adoption studies offer an opportunity to unconfound genes and environment. The findings of adoption studies confirm that there are genetic components for schizophrenia. Even though we have shown that family, twin, and adoption studies have provided strong evidence for the role of genetic factors in schizophrenia, the mode of transmission remains unclear. The results of mathematical modeling studies do not support the single gene model. There is somewhat more support for the multifactorial polygenic model, but the model has also been rejected in several studies. Thus, the pattern of inheritance of schizophrenia has eluded an unambiguous characterization. Genetic linkage analysis promised to clarify the mechanisms of transmission, but early positive reports were subsequently overturned and, to date, there are no consistently replicated positive linkage findings for schizophrenia. There is now a world-wide search for the location of the genes on specific chromosomes which are responsible for schizophrenia. The clinical implications of current work to the future of locating a schizophrenic gene or genes will be discussed.  相似文献   
60.
The Refractance Window® evaporator represents a novel concept in the design of evaporation systems for small food processing plants. In this system thermal energy from circulating hot water is transmitted through a plastic sheet to evaporate water from a liquid product flowing concurrently on the top surface of the plastic. The objectives of this study were to investigate the heat transfer characteristics of this evaporator, determine its energy consumption, and capacity at different tilt angles and product flow rates. The system performance was evaluated with tap water, raspberry juice, and blueberry juice and puree as feed. With a direct steam injection heating method, the steam economy ranged from 0.64 to 0.84, while the overall heat transfer coefficient (U) was 666 W m?2 °C?1. Under this condition, the highest evaporation capacity was 27.1 kg h?1 m?2 for blueberry juice and 31.8 kg h?1 m?2 for blueberry puree. The energy consumption was 2492–2719 kJ kg?1 of water evaporated. Installation of a shell and tube heat exchanger with better temperature control minimized incidences of boiling and frequent discharge of condensate. The steam economy, highest evaporation rate and overall heat transfer coefficient increased to 0.99, 36.0 kg h?1 m?2 and 733 W m?2 °C?1, respectively. Copyright © 2004 John Wiley & Sons, Ltd.  相似文献   
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