445 research outputs found
Vascular white matter lesions negatively correlate with brain metastases in malignant melanoma - results from a retrospective comparative analysis
Brain metastasis (BM) is a major complication of different cancers. There is increasing evidence for influence of vascular factors on BM in patients with non-small cell lung cancer (NSCLC). It is not known if the same is true for other tumors that might rely on different forms of vasculogenesis. The objective of this retrospective study was to evaluate a possible negative association of vascular white matter lesions and vascular risk factors (vasRF) with brain metastases in patients with melanoma
SIOP CNS GCT 96: final report of outcome of a prospective, multinational nonrandomized trial for children and adults with intracranial germinoma, comparing craniospinal irradiation alone with chemotherapy followed by focal primary site irradiation for patients with localized disease.
We conducted a nonrandomized international study for intracranial germinoma that compared chemotherapy followed by local radiotherapy with reduced-dose craniospinal irradiation (CSI) alone, to determine whether the combined treatment regimen produced equivalent outcome and avoided irradiation beyond the primary tumor site(s). Patients with localized germinoma received either CSI or 2 courses of carboplatin and etoposide alternating with etoposide and ifosfamide, followed by local radiotherapy. Metastatic patients received CSI with focal boosts to primary tumor and metastatic sites, with the option to be preceded with chemotherapy. Patients with localized germinoma (n 190) received either CSI alone (n 125) or combined therapy (n 65), demonstrating no differences in 5-year event-free or overall survival, but a difference in progression-free survival (0.97 0.02 vs 0.88 0.04; P .04). Seven of 65 patients receiving combined treatment experienced relapse (6 with ventricular recurrence outside the primary radiotherapy field), and only 4 of 125 patients treated with CSI alone experienced relapse (all at the primary tumor site). Metastatic patients (n 45) had 0.98 0.023 event-free and overall survival. Localized germinoma can be treated with reduced dose CSI alone or with chemotherapy and reduced-field radiotherapy. The pattern of relapse suggests inclusion of ventricles in the radiation field. Reduced-dose craniospinal radiation alone is effective in metastatic disease
Получение полуизолирующего кремния для высоковольтных приборов
Исследовано влияние условий осаждения на структуру и электрофизические свойства пленок поликристаллического кремния, легированного кислородом. Результаты использованы при изготовлении изделий силовой электроники
Holistic corpus-based dialectology
This paper is concerned with sketching future directions for corpus-based dialectology. We advocate a holistic approach to the study of geographically conditioned linguistic variability, and we present a suitable methodology, 'corpusbased dialectometry', in exactly this spirit. Specifically, we argue that in order to live up to the potential of the corpus-based method, practitioners need to (i) abandon their exclusive focus on individual linguistic features in favor of the study of feature aggregates, (ii) draw on computationally advanced multivariate analysis techniques (such as multidimensional scaling, cluster analysis, and principal component analysis), and (iii) aid interpretation of empirical results by marshalling state-of-the-art data visualization techniques. To exemplify this line of analysis, we present a case study which explores joint frequency variability of 57 morphosyntax features in 34 dialects all over Great Britain
The Kosterlitz-Thouless Universality Class
We examine the Kosterlitz-Thouless universality class and show that essential
scaling at this type of phase transition is not self-consistent unless
multiplicative logarithmic corrections are included. In the case of specific
heat these logarithmic corrections are identified analytically. To identify
those corresponding to the susceptibility we set up a numerical method
involving the finite-size scaling of Lee-Yang zeroes. We also study the density
of zeroes and introduce a new concept called index scaling. We apply the method
to the XY-model and the closely related step model in two dimensions. The
critical parameters (including logarithmic corrections) of the step model are
compatable with those of the XY-model indicating that both models belong to the
same universality class. This result then raises questions over how a vortex
binding scenario can be the driving mechanism for the phase transition.
Furthermore, the logarithmic corrections identified numerically by our methods
of fitting are not in agreement with the renormalization group predictions of
Kosterlitz and Thouless.Comment: 36 pages (latex), plus 10 figures (postscript). This version to
appear in Nuclear Physics
The epidemiology of postpartum malaria: a systematic review
Pregnant women are more susceptible to malaria than their non-pregnant counterparts. Less is known about the risk of malaria in the postpartum period. The epidemiology of postpartum malaria was systematically reviewed. Eleven articles fitted the inclusion criteria. Of the 10 studies that compared malaria data from the postpartum period with pregnancy data, nine studies suggested that the risk for malaria infection decreased after delivery. All three studies that compared postpartum data with non-pregnant non-postpartum women concluded that the risk did not return to pre-pregnancy levels immediately after delivery. The results of this review have to be carefully interpreted, as the majority of studies were not designed to study postpartum malaria, and there was large variability in study designs and reported outcomes. Current evidence suggests an effort should be made to detect and radically cure malaria during pregnancy so that women do not enter the postpartum period with residual parasites
- …