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Analytical - diffraction model of V-band propagation for the Radiocommunication Events Management System (REMS)

Abstract

The paper presents an analytical-diffraction propagation model for the needs of the Radiocommunication Events Management System, for coast and ship radio stations in sea area A1. The V-wave propagation in sea area 1 has been analyzed as part of an analysis of ranges of particular radio stations and their ability to establish radio contact. The theoretical basis and assumptions on which the model structure design process is based have been presented. Methods of modelling and presentation of dislocation of particular radio stations and their ranges have been discussed.

Open access
Angioedema, a life-threatening adverse reaction to ACE-inhibitors

Abstract

Angioedema with life-threatening site is one of the most impressive and serious reasons for presenting to the ENT doctor. Among different causes (tumors, local infections, allergy reactions), an important cause is the side-effect of the angiotensin converting enzyme (ACE) inhibitors drugs. ACE-inhibitors-induced angioedema is described to be the most frequent form of bradykinin-mediated angioedema presented in emergency and also one of the most encountered drug-induced angioedema. The edema can involve one or more areas of the head and neck region, the most affected being the face, the lips, the tongue, followed by the larynx, when it may determine respiratory distress and even death.

There are no specific diagnosis tests available and the positive diagnosis of ACE-inhibitors-induced angioedema is an exclusion diagnosis. The authors performed a review of the most important characteristics of the angioedema caused by ACE-inhibitors and present their experience emphasizing the diagnostic algorithm.

Open access
Anticancer effects of olive oil polyphenols and their combinations with anticancer drugs

Abstract

Cancer presents one of the leading causes of death in the world. Current treatment includes the administration of one or more anticancer drugs, commonly known as chemotherapy. The biggest issue concerning the chemotherapeutics is their toxicity on normal cells and persisting side effects. One approach to the issue is chemoprevention and the other one is the discovery of more effective drugs or drug combinations, including combinations with polyphenols. Olive oil polyphenols (OOPs), especially hydroxytyrosol (HTyr), tyrosol (Tyr) and their derivatives oleuropein (Ole), oleacein and oleocanthal (Oc) express anticancer activity on different cancer models. Recent studies report that phenolic extract of virgin olive oil may be more effective than the individual phenolic compounds. Also, there is a growing body of evidence about the combined treatment of OOPs with various anticancer drugs, such as cisplatin, tamoxifen, doxorubicin and others. These novel approaches may present an advanced strategy in the prevention and treatment of cancer.

Open access
Antiproliferative and genotoxic potential of xanthen-3-one derivatives

Abstract

Twelve previously synthesized, biologically active 2,6,7-trihydroxyxanthen-3-one derivatives were evaluated in vitro for antiproliferative activity. Compounds were screened against HeLa, SW620, HepG2 and A549 tumor cell lines. Compound with the trifluormethyl group on C-4’ position of the phenyl ring showed the best inhibitory activity towards HeLa and A549 tumor cells with IC 50 of 0.7 and 4.1 µmol L−1, resp. Compound with chlorine and fluorine substituents on aryl ring showed the best antiproliferative activity against SW620 with IC 50 of 4.1 µmol L–1 and against HepG2 tumor cell line with IC 50 of 4.2 µmol L–1. Analyses of cytotoxic and genotoxic potential of the trifluormethyl derivative were performed with cytokinesis-block micronucleus cytome assay in human lymphocyte culture and revealed no genotoxic and cytotoxic effects. The most potent compounds were subjected to molecular docking simulations in order to analyse bindings to molecular targets and, at the same time, further support the results of experimental cytotoxic tests. Docking studies showed sites of importance in forming hydrogen bonds of the most potent compounds with targets of interest.

Open access
Antiproliferative evaluation of various aminoquinoline derivatives

Abstract

Four classes of aminoquinoline derivatives were prepared: primaquine ureas 1af, primaquine bis-ureas 2af, chloroquine fumardiamides 3af and mefloquine fumardiamides 4af. Their antiproliferative activities against breast adeno-carcinoma (MCF-7), lung carcinoma (H460) and colon carcinoma (HCT 116 and SW620) cell lines were evaluated in vitro, using MTT cell proliferation assay. The results revealed a low activity of primaquine urea and bis-urea derivatives and high activity of all fumardiamides, with IC 50 values in low micromolar range against all tested cancer cell lines.

Open access
Antithrombotic activity of flavonoids and polyphenols rich plant species

Abstract

Cardiovascular diseases represent one of the most notable health problems of the modern civilization. Stroke and heart attack often lead to lethal outcome; essential problem underneath being thrombus formation. Prophylactic approaches include acetylsalicylic acid and clopidogrel therapy on the level of primary hemostasis, i.e., primary clot formation. In the last five years, in the USA, health care expenses related to cardiovascular diseases have increased 50 %, to over 350 billion dollars. Thus, application of plant species and medicinal plants rich in polyphenols in prevention of thrombus formation are of interest. This is supported by the fact that the number of publications on antiaggregatory effect of polyphenols has doubled in the last decade. In this review we focus on antiaggregatory effect of most abundant polyphenols – flavonoids, the effect of plant extracts rich in polyphenols (propolis, species Salvia sp., Calamintha nepeta L., Lavandula angustifolia Mill., Melissa officinalis L, Mentha x piperita L., Ocimum basilicum L., Origanum vulgare L., Rosmarinus officinalis L.) on platelet aggregation, association of chemical composition and antioxidant properties with the observed biological effect, and possible clinical significance of the published results.

Open access
Application and Evaluation of Performance Quality of Hose-Reel Irrigation Machine

Abstract

Considering the global tendency in water saving, this research is focused on practical measurements of even distribution of water. The performance quality is determined by values of coefficients of distribution uniformity and non-uniformity given in percentages. Objects of investigation were belt irrigators with varying input conditions (seven pieces). Testing of hose-reel irrigators took place in Southern and Western Slovakia. Tests were carried out during irrigation of selected agricultural crops (potatoes, vegetables); in these areas, rainwater vessels were distributed at a spacing of 1 or 2 m, perpendicular to the direction of movement of the bracket or tripod with a gun sprinkler. The input conditions, such as machine specifications and weather conditions, were monitored and evaluated for all variants. The data were also analysed along with the linear model through statistical analysis software – one-way analysis of variance ANOVA. Considering the results, it is possible to conclude that there were recorded statistically significant differences for uniformity coefficients, depending not only on the site but also on the specific evaluation methodology (P > 0.05). If the input conditions (site, type of irrigator, sprinkler) were changed, the effect of dependence was demonstrated to a much greater extent (P <0.05, F = 7.08> Fcrit). The results of the non-uniformity coefficients confirmed the statistically significant differences not only in the sample sets of coefficients but also in the selection sets of conditions.

Open access
Application of medicinal plants in several dermatovenerological entities

Abstract

Treatment of skin conditions with medicinal plants has been an ongoing human activity lasting over thousands of years. The use of specific plant species developed regionally, based on local flora. Commonly used medicinal plants for dermatological complaints are: Phlebodium aureum (L.) J. Sm., Ginkgo biloba L., Rosmarinus officinalis L., Panax ginseng C.A.Mey., Allium cepa L., Aloe vera (L.) Burm.f., Capsicum annuum L., Berbe ris aquifolium Pursh, Camellia sinensis (L.) Kuntze, and Podophyllum peltatum L.

The demand for complementary therapeutics is an emerging trend due to the awareness of potential side effects that synthetic drugs might cause. More scientific evidence and better documentation are needed before advising dermatologic patients on herbal medicinal treatment. Standardised extracts and formulations with proven clinical efficacy should be developed for this cause. Here provided review entails the use of herbal medicinal products in the treatment of frequent chronic skin diseases, such as vitiligo, alopecia, psoriasis and genital warts.

Open access
Approximate methods for the optical characterization of inhomogeneous thin films: Applications to silicon nitride films

Abstract

In this paper the overview of the most important approximate methods for the optical characterization of inhomogeneous thin films is presented. The following approximate methods are introduced: Wentzel–Kramers–Brillouin–Jeffreys approximation, method based on substituting inhomogeneous thin films by multilayer systems, method based on modifying recursive approach and method utilizing multiple-beam interference model. Principles and mathematical formulations of these methods are described. A comparison of these methods is carried out from the practical point of view, ie advantages and disadvantages of individual methods are discussed. Examples of the optical characterization of three inhomogeneous thin films consisting of non-stoichiometric silicon nitride are introduced in order to illustrate efficiency and practical meaning of the presented approximate methods.

Open access
Assessment of the Insolvency Risk in Companies Listed on the Bucharest Stock Exchange

Abstract

The present study presents, from the theoretical and pragmatic point of view, 6 of the established score models regarding the assessment of the insolvency risk, belonging to the Anglo-Saxon, Continental and Romanian schools. The research sample is made up of 26 companies belonging to the hotel industry and restaurants, listed on the Bucharest Stock Exchange. The research was carried out over a period of 11 years (2007-2017). Following the application of the score models, it was found that during the period covered by the research, a number of 14 companies had a relatively high insolvency risk and 12 of them had a relatively low insolvency risk.

Open access