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排序方式: 共有544条查询结果,搜索用时 15 毫秒
1.
R Centurioni P Leoni M Candela M Cristina Refe A Stella Strusi L Fabietti G Danieli 《Canadian Metallurgical Quarterly》1996,87(4):161-163
In absence of thrombocytosis, periodic bloodlettings represent the elective therapy of polycythemia vera. In the present study we tested if neocytoapheresis, a method able to remove large quantities of younger, and then bigger red cells could represent an alternative therapeutic choice in these patients. We found that the employment of neocytoapheresis produced a remarkable delay in the time of procedures with a mean interval of 100 +/- 55 days. The mean value of hematocrit before neocytopheresis is resulted statistically different in comparison with the hematocrit after the procedure (p = 0.0001). The reticulocyte count is resulted higher in apheresis product in comparison with the blood control measured before procedure (p = 0.0001). In the same way, the mean corpuscular volume in the collection bags was higher than the volume measured before neocytoapheresis (p = 0.0095). We did not find any variation about the mean values of white blood cells and platelets before and after neocytoapheresis in the patients examined. These preliminary data seem to underline a better withdrawal of big size cells by this technique suggesting the efficacy of neocytoapheresis in the treatment of polycythemia vera. 相似文献
2.
3.
M Bazzan G Gruden S Stella A Vaccarino G Tamponi C Olivetti S Giunti P Cavallo-Perin 《Canadian Metallurgical Quarterly》1998,41(7):767-771
Insulin-like growth factor II (IGF-II) plays a key role in mammalian growth, influencing foetal cell division and differentiation and possibly metabolic regulation. The mature 67 amino acid peptide shares sequence homology with both insulin and IGF-I. The liver is the main endocrine source of IGFs, but autocrine/paracrine activity is found in most tissues. The type 1 receptor mediates most of the biological effects of IGF-I and IGF-II; the type 2 receptor is involved with IGF-II degradation. Binding proteins may both localise IGFs to the receptors and regulate their activities. The IGF2 gene is maternally imprinted in mouse and human. Relaxation of IGF2 imprinting occurs in the Beckwith-Wiedemann syndrome of somatic overgrowth, sporadic Wilms' tumour and a number of other cancers. In the general adult population, the IGF2-INS gene cluster may also influence body weight, in which case IGF-II function could become a target for therapeutic intervention in obesity. 相似文献
4.
Roberto Truzoli Veronica Pirola Stella Conte 《Journal of Computer Assisted Learning》2021,37(4):940-952
The lockdown due to COVID-19 in Italy resulted in the sudden closure of schools, with a shift from traditional teaching to the online one. Through an online questionnaire, this survey explores teachers' experience of online teaching, the level of risk factors (e.g., stress) and protective factors (e.g., locus of control) and their impact on satisfaction levels during the social distancing. One hundred seven high school teachers from Lombardy, an Italian region very affected by the COVID-19 outbreak, participated. Results show that depression and stress are the main predictors of satisfaction levels for online teaching. In addition, coping, locus of control and self-efficacy emerge as important protective factors. Finally, although there is great satisfaction with the online teaching experience, critical elements emerged. This study is relevant because it describes the critical elements of the online teaching experience, and identifies some protective factors and the main risk factors in teachers operating in an area strongly marked by social restrictions imposed by the pandemic. High school teachers emerge as a sub-group of the general population with specific psychological reactions. Considering the results, it is possible to suggest providing high-quality educational support and crisis-psychological oriented services to teachers, and help to maintain the psychological well-being. 相似文献
5.
Michael Carl Maite Melero Toni Badia Vincent Vandeghinste Peter Dirix Ineke Schuurman Stella Markantonatou Sokratis Sofianopoulos Marina Vassiliou Olga Yannoutsou 《Machine Translation》2008,22(1-2):67-99
METIS-II was an EU-FET MT project running from October 2004 to September 2007, which aimed at translating free text input without resorting to parallel corpora. The idea was to use “basic” linguistic tools and representations and to link them with patterns and statistics from the monolingual target-language corpus. The METIS-II project has four partners, translating from their “home” languages Greek, Dutch, German, and Spanish into English. The paper outlines the basic ideas of the project, their implementation, the resources used, and the results obtained. It also gives examples of how METIS-II has continued beyond its lifetime and the original scope of the project. On the basis of the results and experiences obtained, we believe that the approach is promising and offers the potential for development in various directions. 相似文献
6.
Stella Clarke Gerhard Schillhuber Michael F. Zaeh Heinz Ulbrich 《Multimedia Systems》2008,13(4):253-261
The remote nature of telepresence scenarios can be seen as a strongpoint and also as a weakness. Although it enables the remote
control of robots in dangerous or inaccessible environments, it necessarily involves some kind of communication mechanism
for the transmission of control signals. This communication mechanism necessarily involves adverse network effects such as
delay. Three mechanisms aimed at improving the effects of network delay are presented in this paper: (1) Motion prediction
to partially compensate for network delays, (2) force prediction to learn a local force model, thereby reducing dependency
on delayed force signals, and (3) haptic data compression to reduce the required bandwidth of high frequency data. The utilized
motion prediction scheme was shown to improve operator performance, but had no influence on operator immersion. The force
prediction provided haptic feedback through synchronous forces from the local model, thereby stabilizing the control loop.
The developed haptic data compression scheme reduced the number of packets sent across the network by 90%, while improving
the quality of the haptic feedback. 相似文献
7.
A. Stella G. Sartoni G. Giugliarelli M. R. D'Orsogna 《International Journal of Thermophysics》1998,19(4):1209-1218
Quenched geometric disorder of a wall delimiting a spectator phase can have dramatic effects on the nature of critical wetting transitions. We consider self-affine walls in 2D with roughness exponent W. Transfer matrix results for directed interfacial models with short-range interactions suggest that wetting turns first-order as soon as W exceeds 0, the anisotropy index of interface fluctuations in the bulk. Discontinuous interface depinning is best identified by a peculiar two-peak structure in the statistical distributions of wall–interface contacts obtained by sampling over disorder. On the other hand, for W<0 wetting remains continuous, most plausibly in the same universality class as with flat walls. This occurs both with ordered (0 = 1/2) and with bond-disordered (0 = 2/3) bulk. A precise location of the thresholds at W = 0 can be argued on the basis of an analysis of different terms in the interfacial free energy. This analysis elucidates the peculiar role played by the intrinsic interfacial roughness and suggests extensions of the results to 3D and to long-range substrate forces. 相似文献
8.
Our aim is to provide an autonomous vehicle moving into an indoor environment with a visual system to perform a qualitative 3D structure reconstruction of the surrounding environment by recovering the different planar surfaces present in the observed scene.The method is based on qualitative detection of planar surfaces by using projective invariant constraints without the use of depth estimates. The goal is achieved by analyzing two images acquired by observing the scene from two different points of view. The method can be applied to both stereo images and motion images.Our method recovers planar surfaces by clustering high variance interest points whose cross ratio measurements are preserved in two different perspective projections. Once interest points are extracted from each image, the clustering process requires to grouping corresponding points by preserving the cross ratio measurements.We solve the twofold problem of finding corresponding points and grouping the coplanar ones through a global optimization approach based on matching of high relational graphs and clustering on the corresponding association graph through a relaxation labeling algorithm.Through our experimental tests, we found the method to be very fast to converge to a solution, showing how higher order interactions, instead to giving rise to a more complex problem, help to speed-up the optimization process and to reach at same time good results. 相似文献
9.
Panagiotis Papadakos Nikos Armenatzoglou Stella Kopidaki Yannis Tzitzikas 《Knowledge and Information Systems》2012,30(3):493-525
Most Web Search Engines (WSEs) are appropriate for focalized search, i.e., they make the assumption that users can accurately
describe their information need using a small sequence of terms. However, as several user studies have shown, a high percentage
of search tasks are exploratory, and focalized search very commonly leads to inadequate interactions and poor results. This
paper proposes exploiting static and dynamically mined metadata for enriching web searching with exploration services. Online results clustering, which is a mining task of dynamic nature since it is based on query-dependent snippets, is useful for providing users with
overviews of the top results and thus allowing them to restrict their focus to the desired parts. On the other hand, the various
static metadata that are available to a search engine (e.g., domain, language, date, and filetype) are commonly exploited only through the
advanced (form-based) search facilities that some WSEs offer (and users rarely use). We propose an approach that combines
both kinds of metadata by adopting the interaction paradigm of dynamic taxonomies and faceted exploration, which allows the users
to restrict their focus gradually using both static and dynamically derived metadata. Special focus is given on the design
and analysis of incremental algorithms for speeding up the exploration process. The experimental evaluation over a real WSE
shows that this combination results to an effective, flexible, and efficient exploration experience. Finally, we report the
results of a user study indicating that this direction is promising in terms of user preference, satisfaction, and effort. 相似文献
10.
Vitamin B1 has been determined in a large number of beers by the fermentation method of Schultz, Atkin and Frey which has not previously been applied to worts and beers. In general, the highest amounts were found in beers of high original gravity and in those made almost entirely from malt. Well-attenuated and unprimed beers give the highest ratio, units of B1: calories. During the brew the malt, almost the sole source of vitamin B1, yields up the vitamin to the wort, which in its turn loses most of it to the yeast. Most of the vitamin B1 results have been confirmed by the thiochrome method involving an entirely different principle, whilst the general validity of both methods was further confirmed by animal feedings tests. Determination of Riboflavin (vitamin B2) by the microbiological method of Snell and Strong has led to the following conclusions:—Riboflavin is formed during germination of barley and in growing yeast. Most of the riboflavin of the malt passes into the wort during mashing and sparging and remains in the beer, the yeast not taking out any appreciable quantity. The number of microgrms. of riboflavin per 100 ml. of beer, in general, exceeds somewhat the number of degrees of original gravity. 相似文献