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Search Results: 1 - 10 of 7056 matches for " Daniela Antonova "
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Chemical composition of the essential oils of Rhodiola rosea L. of three different origins
Evstatieva Ljuba,Todorova Milka,Antonova Daniela,Staneva Jordanka
Pharmacognosy Magazine , 2010,
Abstract: Rhodiola rosea L. (Crassulaceae), or "rose root" is a perennial herbaceous plant, distributed in the Northern Hemisphere. Pharmacological studies have shown that R. rosea exhibits different biological activities - antioxidant, antidepressant, anticancer, etc. The aim of this study was to compare the chemical composition of essential oils from rhizomes of three commercial samples of R. rosea originated from Bulgaria (sample 1), China (sample 2) and India (sample 3). The oils were analyzed by GC and GC-MS. Thus, the main volatile component in the Bulgaria and Chinese R. rosea was geraniol, followed by myrthenol in sample 1 or octanol in sample 2. Phenethylalcohol was a principal constituent in the Indian oil. Myrtenol and octanol were in significant amounts too. Aliphatic hydrocarbons were characteristic of the latter sample. It is notable that cinnamyl alcohol, which was present in large concentration in Bulgarian sample, was not detected in the other two samples. The obtained results showed considerable differences in the composition of the studied three origins of R. rosea.
GC-MS studies of the chemical composition of two inedible mushrooms of the genus Agaricus
Assya Petrova, Kalina Alipieva, Emanuela Kostadinova, Daniela Antonova, Maria Lacheva, Melania Gjosheva, Simeon Popov, Vassya Bankova
Chemistry Central Journal , 2007, DOI: 10.1186/1752-153x-1-33
Abstract: Our GC-MS studies on the volatile fractions and butanol extracts resulted in the identification of 44 and 34 compounds for A. placomyces and A. pseudopratensis, respectively, including fatty acids and their esters, amino acids, and sugar alcohols. The most abundant constituent in the volatiles and butanol were phenol and urea respectively. We also identified the presence of ergosterol and two Δ7-sterols. In addition, 5α,8α-Epidioxi-24(ξ)-methylcholesta-6,22-diene-3β-ol was isolated for the first time from both mushrooms. Our study is therefore the first report on the chemical composition of these two species.The results obtained contribute to the knowledge of the chemical composition of mushrooms belonging to the Agaricus genus, and provide some explanation for the reported mild toxicity of A. placomyces and A. pseudopratensis, a phenonomenon that can be explained by a high phenol content, similar to that found in other Xanthodermatei species.Mushrooms in the genus Agaricus have a worldwide distribution, with up to 90 species recorded in Europe. The genus includes the most economically important and commercially cultivated mushroom in the world, A. bisporus (button mushroom) as well as many other edible species [1]. Some Agaricus species are inedible, including A. placomyces and A. pseudopratensis Bohus, which are similar in appearance to certain edible species, yet are known to possess unpleasant odours and result in gastrointestinal problems if consumed [2,3]. To the best of our knowledge, there is no information available in the literature concerning the chemical composition of these two species.In this article, we report the results of the GC-MS analyses of volatile and polar compounds, in addition to the sterol fraction obtained from the fruiting bodies of A. placomyces and A. pseudopratensis. The results can help characterise the species investigated, indicate the presence of some biologically active compounds and shed light upon their reported mild toxicity.T
Book review: The ants of Poland with reference to the myrmecofauna of Europe - Fauna Poloniae (New series) vol. 4 By Wojciech Czechowski, Alexander Radchenko, Wies awa Czechowska, Kari Veps l inen
Vera Antonova
ZooKeys , 2012, DOI: 10.3897/zookeys.247.4369
Abstract:
About the relationship between concepts linguistic consciousness and professional language consciousness
Antonova I. S.
Sociosfera , 2010,
Abstract: The article discuses some aspects of professional verbal consciousness which is viewed as a part of verbal consciousness in general. We assume that professional verbal consciousness has its own specificity, which includes professional semantic fields of one and the same professional sphere as well as models of consciousness which externalize specific conscious images.
Collaboration and Innovation in Sweden and Bulgaria: A Study of a Mature Industry
Maya Hoveskog,Diana Antonova
International Journal of Economic Sciences and Applied Research , 2011,
Abstract: Nowadays, creation, exchange and transfer of knowledge (CETK) are turning into the most significant activity for companies. This article sheds light on Swedish and Bulgarian companies within a mature industry in terms of their knowledge flows for collaboration and innovation. Companies from the two countries as well as Small and medium enterprises (SMEs) and large firms are compared. Quantitative and qualitative research methods are combined. A set of variables which have a positive relationship with the companies' researchand development (R&D) activities and innovation is developed.It was found out that the set of variables employed can predict the innovation and R&D of companies, laying of electrochemical and conversion surface treatments with functional and decorative purposes (ECSTFDP) for the sample. In both countries innovation and R&Dare positively affected by places for knowledge exchange followed by collaboration factors and market situation. However, the factors for collaboration and interaction are the most important for increasing the innovation activities in companies with ECSTFDP, irrespectiveof size, age and country of operation. Moreover, the article reveals the vital role of the social element in the CETK, which is also emphasized in the knowledge management literature. Furthermore, it illustrates that companies are influenced by the number of factors in this collaboration and actively evaluate the trade-offs from it. Additionally, the dynamics of the market is setting the pace and degree of newness of innovation and R&D activities.
Saami pulmakombed
Aleksandra Antonova,Jaan Sarv
M?etagused. Hüperajakiri , 1999,
Abstract: The material collected and published on the traditional wedding customs of the Sami of the Kola peninsula is relatively scarce. The article introduces folkloric material connected to the Sami wedding tradition. The first part of the article provides a description of a Sami wedding recorded by Aleksandra Antonova, focusing on the description of the wedding customs. Author uses traditional terminology of Sami. The second part of the article includes some notes of unique wedding song recordings with comments written by Jaan Sarv, and the deciphering of song lyrics written by both authors.
Events
Antonova Alla Borisovna
Magister Dixit , 2012,
Abstract:
THE PROBLEMS WITH TEACHING ENGLISH AS A SECOND FOREIGN LANGUAGE TO STUDENTS OF THE ASIAN-PASIFIC REGION
Antonova Alla Borisovna
Magister Dixit , 2013,
Abstract: The article briefly discusses the problems the English teacher faces working with students from the Asian-Pacific region as seen in the example of teaching at the International department of Irkutsk State Linguistic University.
Mathematical modeling of straight position and gait to human health problems of diagnosis
Antonova Natalia Evgenievna
Vestnik Astrahanskogo Gosudarstvennogo Tehni?eskogo Universiteta. Seria: Upravlenie, Vy?islitel?naa Tehnika i Informatika , 2012,
Abstract: For solution of a problem of diagnostics of human musculoskeletal apparatus diseases it is neces-sary to have the corresponding biometric information, which is obtained by using the appropriate med-ical equipment. It requires the development of physical and mathematical models, as well as the corre-sponding algorithms and software for information processing. In order to ensure longitudinal-transverse stabilization and control of the human body in the sagittal and frontal planes in the modes of saving vertical stand and balance in the vertical gait using two channels of biological feedbacks. These channels form reflex arches of balance and realize a cybernetic principle of negative feedback.
Stress and breast cancer: from epidemiology to molecular biology
Lilia Antonova, Kristan Aronson, Christopher R Mueller
Breast Cancer Research , 2011, DOI: 10.1186/bcr2836
Abstract: Studies have estimated that approximately 50% of breast cancer incidence can be attributed to known genetic, physiologic, or behavioral risk factors [1], with genetic risk factors accounting for 5 to 10% of breast cancer cases [2]. Established physiological and behavioral risk factors for breast cancer include having a first-degree relative with breast cancer, early menarche, late menopause, nulliparity or bearing of first child at a later age, overweight after menopause, certain types of benign breast diseases, alcohol consumption, and long-term use of menopausal estrogen replacement therapy [3]. In addition to these well-characterized contributors, other factors, whose effects have been more difficult to evaluate, are suspected of conferring increased breast cancer risk. These factors include smoking, certain aspects of nutrition (meat and fat consumption), physical activity, and psychological stress [4,5].The possible contribution of psychological stress to breast cancer development has been extensively studied. Literature on the topic is not only abundant, spanning several decades, but is scattered between the fields of epidemiology, physiology, and molecular biology. Whereas the largest amount of literature focuses on using epidemiologic methods to look for a connection between exposure to stress and subsequent breast cancer diagnosis, this portion of the literature is also the most difficult to assess. Studies in this area differ greatly in their findings, probably due to differences in factors such as study design, the effects of confounding, type of stress exposure, and timing of stress exposure or stress exposure measurement. On the other hand, animal literature on the topic is simpler to interpret, for the most part pointing to a connection between physiological stress signaling and breast cancer development. This literature is limited, however, by a lack of variability in stress exposure parameters and the differences in breast physiology and development
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