University of Rijeka

About: University of Rijeka is a education organization based out in Rijeka, Croatia. It is known for research contribution in the topics: Population & Tourism. The organization has 3471 authors who have published 7993 publications receiving 110386 citations. The organization is also known as: Rijeka University & Sveučilište u Rijeci.

Heat transfer analysis of fin-and-tube heat exchangers with flat and louvered fin geometries

Abstract: This paper analyzes the fluid flow and heat exchange on the air side of a multi-row fin-and-tube heat exchanger. A comparison is given between fin-and-tube heat exchanger characteristics with flat and louvered fins in a wider range of operating conditions defined by Reynolds number (based on fin spacing and air frontal velocities). The detailed representation of calculated data for the louvered heat exchanger shows significantly better heat transfer characteristics and a slightly higher pressure drop. The CFD procedure was validated by comparing the numerical simulation results with the experimental results showing the minimal average Nusselt number deviation and an almost perfectly corresponding pressure drop.

Non-redundant and Redundant Roles of Cytomegalovirus gH/gL Complexes in Host Organ Entry and Intra-tissue Spread

Abstract: Herpesviruses form different gH/gL virion envelope glycoprotein complexes that serve as entry complexes for mediating viral cell-type tropism in vitro; their roles in vivo, however, remained speculative and can be addressed experimentally only in animal models. For murine cytomegalovirus two alternative gH/gL complexes, gH/gL/gO and gH/gL/MCK-2, have been identified. A limitation of studies on viral tropism in vivo has been the difficulty in distinguishing between infection initiation by viral entry into first-hit target cells and subsequent cell-to-cell spread within tissues. As a new strategy to dissect these two events, we used a gO-transcomplemented ΔgO mutant for providing the gH/gL/gO complex selectively for the initial entry step, while progeny virions lack gO in subsequent rounds of infection. Whereas gH/gL/gO proved to be critical for establishing infection by efficient entry into diverse cell types, including liver macrophages, endothelial cells, and hepatocytes, it was dispensable for intra-tissue spread. Notably, the salivary glands, the source of virus for host-to-host transmission, represent an exception in that entry into virus-producing cells did not strictly depend on either the gH/gL/gO or the gH/gL/MCK-2 complex. Only if both complexes were absent in gO and MCK-2 double-knockout virus, in vivo infection was abolished at all sites.

Orientations to happiness, subjective well-being and life goals

Abstract: People pursue happiness through different paths: pleasure, engagement and meaning, which are differently related to well-being. The aim of this research was to compare subjective well-being, life goals and self-control of people with different profiles of orientations to happiness. Students (484 females, 278 males; mean age 20.60) rated their life satisfaction, positive and negative affect, orientations to happiness, and self-control. Based on the K-means cluster analysis participants were grouped into four groups: students who highly endorse hedonic and eudaimonic orientation (the "Full life" group), those who do not endorse either of them (the "Empty life" group), those who live eudaimonic and those who live hedonic life. People who live a full life are the happiest, they value intrinsic life goals and have good self-control. Contrary, people who live empty lives have the lowest well-being, they value extrinsic and intrinsic life goals less than other people and have low self-control.

p53 Protein Expression and Cell Proliferation in Non-Neoplastic and Neoplastic Proliferative Skin Diseases:

Abstract: Aims and background The p53 protein is essential for the regulation of cell proliferation and its aberrant accumulation is usually seen in malignant tumors but also occurs in squamous epithelium of inflammatory skin diseases characterized by hyperproliferation. The aim of this study is to elucidate the role of the p53 tumor suppressor protein in the pathogenesis of different hyperproliferative, non-malignant and malignant skin diseases, and to determine the association between p53 overexpression and cell proliferation. We also investigated the influence of aging on p53 and Ki-67 protein expression. Methods One hundred and fifty skin specimens divided into 30 samples each of normal skin (NS), psoriatic skin (PS), keratoacanthomas (KA), basal cell carcinomas (BCC), and squamous cell carcinomas (SCC) were examined immunohistochemically to assess p53 and Ki-67 protein expression. Results p53 immunostaining of NS, PS, KA, BCC and SCC was detected in 39.0%, 46.7%, 66.7%, 80% and 86.7% of cases, respectively. Median values and ranges of p53 protein expression were as follows: 0.0% (range, 0.0-1.8%) in NS, 0.0% (range, 0.0-6.5%) in PS, 9.2% (range, 0.0-24.0%) in KA, 19.3% (range, 0.0-48.1%) in BCC and 30.1% (range, 0.0-68.1%) in SCC. p53- and Ki-67-positive cells were present in basal (NS) and suprabasal layers (PS), and not only in cancer nests of KA, BCC and SCC but also in dysplastic and even morphologically normal epidermis adjoining cancers. The positivity of p53 and Ki-67 proteins differed significantly among the groups, with no differences in p53 expression between NS and PS and in Ki-67 expression between PS and KA. Within all groups there was a significant correlation between p53 and Ki-67 expression. Lesion location and patient age, with the exception of location in PS and age in BCC, were significantly related to p53 and Ki-67 expression in all groups. Conclusions Our findings suggest that p53 overexpression occurs mainly in neoplastic skin lesions, although it may also occur in squamous epithelium of inflammatory skin diseases such as PS, as well as in normal skin epithelium. It is associated with cell proliferation in normal as well as altered epithelium. p53 protein overexpression is an age-related process and significantly associated with sun exposure, especially in NS and PS but also in KA and SCC. Our findings suggest that Ki-67 rate and p53 protein expression reflect the degree of malignancy in the examined cutaneous neoplasms.