University of Graz

About: University of Graz is a education organization based out in Graz, Steiermark, Austria. It is known for research contribution in the topics: Population & Context (language use). The organization has 17934 authors who have published 37489 publications receiving 1110980 citations. The organization is also known as: Carolo Franciscea Graecensis & Karl Franzens Universität.

A Coronal Thick-Target Interpretation of Two Hard X-Ray Loop Events

Abstract: We report a new class of solar flare hard X-ray (HXR) sources in which the emission is mainly in a coronal loop so dense as to be collisionally thick at electron energies up to 50 keV. In most of the events previously reported, most of the emission is at the dense loop footpoints, although sometimes with a faint high-altitude component. HXR RHESSI data on loop dimensions and nonthermal electron parameters and GOES soft X-ray data on hot loop plasma parameters are used to model coronal thick-target physics for two "discovery" events (2002 April 14 [23:56 UT] and 2002 April 15 [23:05 UT]). We show that loop column densities N are consistent with (1) a nonthermal coronal thick-target interpretation of the HXR image and spectrum; (2) chromospheric evaporation by thermal conduction from the hot loop rather than by electron beam heating; and (3) the hot loop temperature being due to a balance of thick-target collisional heating and (mainly) conductive cooling.

HDL cholesterol: reappraisal of its clinical relevance.

Abstract: Background While several lines of evidence prove that elevated concentrations of low-density lipoproteins (LDL) causally contribute to the development of atherosclerosis and its clinical consequences, high-density lipoproteins are still widely believed to exert atheroprotective effects. Hence, HDL cholesterol (HDL-C) is in general still considered as “good cholesterol”. Recent research, however, suggests that this might not always be the case and that a fundamental reassessment of the clinical significance of HDL-C is warranted.

B7 family molecules are favorably positioned at the human maternal-fetal interface.

Abstract: The human placenta utilizes both active and passive mechanisms to evade rejection by the maternal immune system. We investigated the pattern of expression of the B7 family of immunomodulatory molecules B7-H1 (PD-L1), B7-2 (CD86), and B7-1 (CD80) at the term maternal-fetal interface. Northern blot and reverse transcription-polymerase chain reaction (RT-PCR) analyses showed that B7-H1 mRNA is abundant in term placenta and that cytotrophoblasts are sources of this message. Immunohistochemistry demonstrated that B7-H1 is constitutively expressed by the syncytiotrophoblast and by extravillous cytotrophoblasts, both of which are juxtaposed to maternal blood and tissue. By contrast, placental stromal cells, including macrophages, lacked the protein. Expression of B7-H1 protein was low in first-trimester placenta compared to second- and third-trimester tissue (P < 0.05) and was enhanced in cultured cytotrophoblasts by treatment with either interferon-gamma or epidermal growth factor (P < 0.05), suggesting that one or both of these mediators regulates B7-H1 expression in the placenta. RT-PCR and immunofluorescence analysis of term placental tissue revealed different patterns of expression of the immunostimulatory protein, B7-2. In contrast to B7-H1, B7-2 mRNA and protein were absent in cytotrophoblast cells but present in maternal macrophages and some fetal macrophages. The B7-1 mRNA and protein were absent at the maternal-fetal interface. These studies document expression of the B7 family proteins at the maternal-fetal interface and demonstrate that B7-H1 is positioned such that it could facilitate protection of fetal cells against activated maternal leukocytes. Conversely, B7-2 was absent on trophoblasts and was appropriately localized to fetal and maternal macrophages, which may participate in antigen presentation.

Three-point checklist of dermoscopy. A new screening method for early detection of melanoma.

Abstract: Background: Dermoscopy used by experts has been demonstrated to improve the diagnostic accuracy for melanoma. However, little is known about the diagnostic validity of dermoscopy wh