3,405 research outputs found
(Ba, Sr)TiO3 system under DC-bias field .2. Induced and intrinsic pyroelectric coefficients and figures-of-merit
No full textThe pyroelectric coefficient under the applied DC-bias field consists of two terms: (i) induced pyroelectric coefficient, (ii) intrinsic (true) pyroelectric coefficient From the dielectric/pyroelectric data of both the unsubstituted (Ba, Sr)TiO3 (BST; with Ba: Sr = 2:1) and the Zr-substituted BST, it was shown that the intrinsic pyroelectric coefficient made a dominant contribution to the net pyroelectric coefficient below the Curie temperature (T-c). On the other hand, the induced pyroelectric coefficient contributes significantly to the net pyroelectric response above T,by virtue of the reduction in the temperature-dependent spontaneous polarization. The behavior of the induced pyroelectric response for the Zr-substituted BST was further analyzed using a semiempirical model based on the concept of a Gaussian distribution of the local Curie points. The two practically important figures-of-merit (F-V and F-D) under various DC-bias fields were estimated as a function of temperature. An optimum condition of the composition for the thermostability of pyroelectric figure-of-merit at near ambient temperature was deduced from the analysis, and it was 10 at. % Zr-substitution with Ba: Sr = 3:1 (ie., Ba0.75Sr0.25Ti0.9Zr0.1O3).X1114sciescopu
(Ba, Sr)TiO3 system under DC-bias field .1. Improvement on the thermostability of pyroelectric response by Zr-substitution
No full text(Ba, Sr)TiO3 (BST) is being actively investigated as a prime candidate material for thermal imaging sensor that utilizes the dielectric bolometer (DB) mode. However, strong temperature-dependent pyroelectric properties of BST severely limit its widespread applications. In the present study, we have attempted to improve the thermostability of pyroelectric response by narrowing the temperature intervals between the three consecutive rhombohedral-orthorhombic-tetragonal-cubic phase transitions. For this purpose, we have partially substituted Zr ions for Ti ions in the B-site of perovskite structure. It was observed that the three pyroelectric peaks associated with the structural phase transitions coalesced together at near room temperature, exhibiting a broad pyroelectric response at higher Zr concentrations (greater than or equal to 10 at.% Zr). It was shown that the broadness of pyroelectric response under the DC-bias field was closely correlated with the broadness of pyroelectric response in the absence of DC-bias field. Therefore, the thermostability of pyroelectric response under the DC-bias field was also significantly improved by the Zr-substitution.X115sciescopu
Relaxation time distribution of deuterated dipole glass
No full textWe have shown that none of the well-known relaxation functions such as the Cole-Cole, Cole-Davidson and KWW functions are satisfactory to describe the observed dielectric relaxation behavior of the deuterated rubidium-ammonium dihydrogen phosphate dipole glass (DRADP-x). The correlated domain model of Chamberlin was in qualitative agreements with the experimental observations of the dipole glass for (i) a long tail at lower frequency side, (ii) increase in the asymmetry of the dielectric loss spectrum with decreasing temperature.X11sciescopu
Disruption of smooth pursuit eye movements in cirrhosis: relationship to hepatic encephalopathy and its treatment.
No full textThe use of indomethacin to demonstrate an enterotoxic activity in extracts of entamoeba histolytica trophozoites, 1982
No full textAxenically cultured Entamoeba histolytica trophozoites of the pathogenic strain HM-1 were harvested in phosphate buffered saline (PBS). The cells were disrupted with ultrasonic energy, centrifuged, and the supernatant fluid tested for enterotoxic activity in the i[n vivo rabbit ileum loop .and-the rat proximal colon loop. This HM-1 extract, equivalent to 106 trophozoites/ml, had no effect on intestinal absorption in either animal model, but secretion resulted in both preparations when indomethacin (0.1 mg/kg) was administered subcutaneously to reduce cytoprotection. In the rat colon a lower dose of indomethacin was ineffective in allowing the ameba preparation to cause frank secretion, while higher doses, 1 and 10 mg/kg, directly inhibited this secretory response. In the absence of indomethacin, a preparation equivalent to 107 trophozoites/ml reduced colonic absorption without producing secretion, while a preparation of 107 trophozoites/ml of the non-pathogenic E_. histolytica-like Laredo strain was ineffective even in the presence of 0.1 mg/kg indomethacin. The HM-1 enterotoxic activity was heat labile. Prior exposure of the loop lumen to fetuin (100 wg/ml) blocked the secretory response to subsequent enterotoxin exposure in indotnethacin-treated animals. Fetuin inhibition of secretion could not be reversed by inoculating the loop with fresh trophozoite extract at hourly intervals for 4 hours
An assessment of the impact of possible CAP reform scenarios on Romanian agriculture
No full textUsing a simplified model, with key-variable the prices of two different possible scenarios of CAP reform after 2013 (moderate and radical), this paper present a comparison between the price effects of implementation of each reform scenario at 2015 horizon on Romanian agriculture. This short analysis shows that, under the presented hypotheses, the net welfare effect, due to the price changes, for the selected products, is positive in both reform scenarios, yet greater in the case of the radical reform. Integrated in the large context of Romanian development, it seems that the influence of CAP reform upon agriculture and rural areas will be most likely a gradual one: an interpenetration between the two scenarios is foreseeable, starting with the moderate reform that will dominate the period around 2013, the reform measures acquiring a more radical character afterwards.CAP reform, Romania, welfare effects, Agricultural and Food Policy,
The Role of Relationally Embedded Network Ties in Resource Acquisition of British Nonprofit Organizations
No full textAs nonprofit and charity organizations face increasing competition, there have been growing interests in how nonprofit organizations conduct commercial activities to raise funds as well as grow their business. However, there is lack of prior research about market-oriented and/or commercial activities in the context of nonprofit business. This study examines the process of how nonprofit organizations use relationally embedded network ties to acquire financial, human, and human capital resources to fulfill their social mission and achieve business growth. The study investigates commercial activity of three U.K.-based nonprofit organizations using the case study method. The findings contribute to insights into components of network ties for acquiring three different network resources of financial, human, and human capital. Nonprofit organizations leverage social mission to improve their ability to acquire network resources. The findings also suggest the charity and social mission of nonprofit business enhance trustworthiness in relationally embedded network ties for resource acquisition
Prevalence and clinical picture of celiac disease in Turner syndrome
No full textPrevalence and clinical picture of celiac disease in Turner syndrome.
Bonamico M1, Pasquino AM, Mariani P, Danesi HM, Culasso F, Mazzanti L, Petri A, Bona G; Italian Society Of Pediatric Gastroenterology Hepatology (SIGEP); Italian Study Group for Turner Syndrom (ISGTS).
Author information 1Department of Pediatrics, University of Rome La Sapienza, 00161 Roma, Italy.
Abstract
A multicenter study of Turner syndrome (TS) patients was carried out to estimate the prevalence of celiac disease (CD) and to detect clinical characteristics and laboratory data of affected patients. Three hundred eighty-nine girls with TS were screened by IgA antigliadin antibodies and/or antiendomysial antibodies. Intestinal biopsy was offered to positive cases. CD was diagnosed in 25 patients. In celiac subjects, anemia, anorexia, and delayed growth (with respect to Italian TS curves) were frequently present; whereas distended abdomen, chronic diarrhea, constipation, and vomiting occurred more rarely. In addition, low serum iron levels, hemoglobinemia, and high values of aminotransferases were observed. Ten patients showed classic CD, 8 showed atypical symptoms, and 7 showed a silent CD. In 11 symptomatic patients, the diagnosis of CD was made at the onset of symptoms, whereas 7 of them showed a median delay of 79 months in diagnosis. Other autoimmune disorders were observed in 40% of the patients. Our study confirms the high prevalence (6.4%) of CD in a large series of TS patients. Moreover, the subclinical picture in 60% of the cases, the diagnostic delay, and the incidence of other autoimmune disorders suggest that routine screening of CD in TS is indicated
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