Search results for "Urea"
showing 10 items of 888 documents
The essential oil composition of the endemic plant species Centaurea vandasii and chemotaxonomy of section Phalolepis (Asteraceae)
2021
In the present study, the chemical composition of the essential oil from aerial parts of the endemic plant species, Centaurea vandasii Velen (sect. Phalolepis, Asteraceae), collected in its locus classicus in Rhodope Mts, Bulgaria, was evaluated by GC-MS. The main components of the oil were hexadecanoic acid (18.3%), tetradecanoic acid (13.8%), caryophyllene oxide (12.1%) and germacrene D (8.4%). Furthermore, a complete literature review on the composition of the essential oils of all the other taxa of Centaurea, belonging to section Phalolepis, studied so far, was performed. HCA (Hierarchical Cluster Analysis) and PCA (Principal Component Analyses) were used in order to demonstrate chemota…
Cytotoxic activity of some natural and synthetic guaianolides
2005
Several natural guaianolides and synthetic derivatives of repin (1) were tested and found to be active against tumor cell replication. Repin (1) and both mono- and di-halohydrin analogues (2, 7-9, 11, 12) showed significant antitumor potency. A more effective compound (17) was obtained by esterificating repin with the paclitaxel side chain.
Palliative Care Education in Undergraduate Nursing Curriculum in Italy
2019
Worldwide, more than 19 million people require palliative care because of an advanced stage of disease. Undergraduate nursing education should include palliative care as the European consensus suggests. In 2004, the European Society of Palliative Care issued a guide for the development of palliative nurse education in Europe. This study aims to describe the extension and characteristics of palliative care education within all of the nursing degree curricula in Italy, as well as to what extent their topics match the European Society of Palliative Care guide. A descriptive study was conducted through the universities web pages. For each degree, the curricula of the academic years from 2010 to…
Recurrent aphthous stomatitis and Helicobacter pylori
2016
Background Recurrent aphthous stomatitis (RAS) is a recurrent painful ulcerative disorder that commonly affects the oral mucosa. Local and systemic factors such as trauma, food sensitivity, nutritional deficiencies, systemic conditions, immunological disorders and genetic polymorphisms are associated with the development of the disease. Helicobacter pylori (H. pylori) is a gram-negative, microaerophile bacteria, that colonizes the gastric mucosa and it was previously suggested to be involved in RAS development. In the present paper we reviewed all previous studies that investigated the association between RAS and H. pylori. Material and Methods A search in Pubmed (MEDLINE) databases was mad…
Molecular Classification of Pesticides Including Persistent Organic Pollutants, Phenylurea and Sulphonylurea Herbicides
2014
Pesticide residues in wine were analyzed by liquid chromatography–tandem mass spectrometry. Retentions are modelled by structure–property relationships. Bioplastic evolution is an evolutionary perspective conjugating effect of acquired characters and evolutionary indeterminacy–morphological determination–natural selection principles; its application to design co-ordination index barely improves correlations. Fractal dimensions and partition coefficient differentiate pesticides. Classification algorithms are based on information entropy and its production. Pesticides allow a structural classification by nonplanarity, and number of O, S, N and Cl atoms and cycles; different behaviours depend …
Iron-Catalyzed Cross-Coupling Reactions of Alkyl Grignards with Aryl Chlorobenzenesulfonates
2021
Aryl sulfonate esters are versatile synthetic intermediates in organic chemistry as well as attractive architectures due to their bioactive properties. Herein, we report the synthesis of alkyl-substituted benzenesulfonate esters by iron-catalyzed C(sp2)–C(sp3) cross-coupling of Grignard reagents with aryl chlorides. The method operates using an environmentally benign and sustainable iron catalytic system, employing benign urea ligands. A broad range of chlorobenzenesulfonates as well as challenging alkyl organometallics containing β-hydrogens are compatible with these conditions, affording alkylated products in high to excellent yields. The study reveals that aryl sulfonate esters are the m…
Influence of N-acetylcysteine on hepatic amino acid metabolism in patients undergoing orthotopic liver transplantation
2001
Experimental treatment with the antioxidant and glutathione precursor N-acetylcysteine (NAC) has been performed in orthotopic liver transplantation (OLT) to reduce reperfusion injury. To investigate the effect of NAC on the hepatic and intestinal amino acid metabolism, intraoperative amino acid exchange rates were studied in liver transplant recipients with high dose NAC treatment (n = 10) and in control patients (n = 9). Treatment with NAC was found to cause a loss of amino acids and increased urea nitrogen release from the liver graft. The net balance of most amino acids was shifted to increased hepatic release or decreased hepatic uptake. The initial cumulative splanchnic release of all …
Biological activity of flucycloxuron, a novel benzoylphenylurea derivative, onTenebrio molitor: comparison with diflubenzuron and triflumuron
1993
Flucycloxuron, a novel benzoylphenylurea (BPU) derivative, exhibited insecticidal activity when injected into newly ecdysed pupae ofTenebrio molitor. Mortality occurs because of defective adult ecdysis. Treatment caused a reduction in both cuticle thickness and incorporation of14C-labelled precursor into chitin, although it had no significant effect on the protein synthesis. The potencies of other BPU compounds as inhibitors of chitin biosynthesis have been examined and results showed that diflubenzuron was less effective than either flucycloxuron or triflumuron.
Volatile Components of Centaurea Bracteata and C. Pannonica subsp. Pannonica growing wild in Croatia
2010
This paper reports on the volatile components of oils from the aerial parts (CBA) and roots (CBR) of Centaurea bracteata Scop. and aerial parts of C. pannonica (Heuffel) Simonkai subsp. pannonica (CPA), two Asteraceae growing wild in Croatia. The volatile components, obtained by hydrodistillation, were determined by GC-MS analysis. The yields (w/w) of the dried oils were 0.10% (CBA), 0.22% (CBR) and 0.09% (CPA), respectively. A total of 91 compounds were identified accounting for 91.1%, 93.3% and 87.9% of the total oil for CBA, CBR and CPA, respectively. All the samples were characterized mainly by hydrocarbons (7.1-34.1%), fatty acids (9.7-45.9%), and oxygenated sesquiterpenes (15.2-16.6%…
Circular dichroism studies on the interaction of sulfonylureas with insulin
1976
The interaction of 5 sulfonylurea derivatives with insuline was investigated by means of circular dichroism measurements. It was found that all sulfonylureas investigated decrease the ellipticity band of insulin at 208 nm, whereas the band at 222 nm remains unaffected. It is suggested that these observations are due to a change of the insulin conformation, provoked by the interaction of the drugs with insulin. It is assumed that such an effect on the insulin conformation can influence the binding properties of insulin, e.g. in respect to the insulin aggregation, to the binding to insulin antibodies and to a bound, inactive form of insulin in the plasma. Some other drugs have similar, but mo…