156 research outputs found

    Carbonic anhydrase inhibitors. Inhibition of the cytosolic and tumor-associated carbonic anhydrase isozymes I, II and IX with some 1,3,4-oxadiazole- and 1,2,4-triazole-thiols

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    Novel mercapto-1,3,4-oxadiazole and -1,2,4-triazole derivatives were synthesized by various pathways starting from 4-(4-halogeno-phenylsulfonyl)benzoic acid hydrazides which were reacted with carbon disulfide or isothiocyanates. The heterocyclic mercaptans prepared in this way were assayed as inhibitors of three physiologically relevant isoforms of the zinc enzyme carbonic anhydrase (CA, EC 4.2.1.1), i.e., the cytosolic CA I and II, and the tumor-associated, transmembrane isozyme CA IX. Interesting biological activity was detected for some of the new mercaptans, with inhibition constants in the low micromolar range

    NEW DATA ABOUT THE CONTROL OF THE PLANTHOPPER METCALFA PRUINOSA (SAY 1830) (HEMIPTERA: FLATIDAE) IN THE TOWN OF PITEŞTI (ARGEŞ COUNTY)

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    Metcalfa pruinosa (Say 1830), an invasive species mentioned in Romania in 2009, was observed first time in Pitești in 2014, a city located in the central-southern part of Romania. In the favourable climatic conditions of the summer of 2015, high density of thedevelopment stages of the pest were seen on many host plants, both woody and herbaceous, in the green areas of the city. The insecticide treatments show the highest effectiveness for the mixture of imidacloprid 75 g/l, deltamethrin 10 g/l, lambda cyhalothrin 50 g/l, associated with pirimiphos methyl 500 g/l, within an interval of 3-5 days. It is important that treatments be applied in combination with 0.1% Silwet to facilitate the action of the active substance. Monitoring and chemical control are required in order to limit the spread of pests in places bordering the city, where there are important vineyards and orchards

    A Schema for Specifying Computational Autonomy

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    A key property associated with computational agency is autonomy, and it is broadly agreed that agents as autonomous entities (or autonomous software in general) have the capacity to become an enabling technology for a variety of complex applications in fields such as telecommunications, e/m-commerce, and pervasive computing. This raises the strong need for techniques that support developers of agentoriented applications in specifying the kind and level of autonomy they want to ascribe to the individual agents. This paper describes a specification schema called RNS ("Roles, Norms, Sanctions") that has been developed in response to this need. The basic view underlying RNS is that agents act as owners of roles in order to attain their individual and joint goals. As a role owner an agent is exposed to certain norms (permissions, obligations and interdictions), and through behaving in conformity with or in deviation from norms an agent becomes exposed to certain sanctions (reward and punishment). RNS has several desirable features which together make it unique and distinct from other approaches to autonomy specification. In particular, unlike other approaches RNS is strongly expressive and makes it possible to specify autonomy at a very precise level

    An Evolutionary Learning Approach for Adaptive Negotiation Agents

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    Developing effective and efficient negotiation mechanisms for real-world applications such as e-Business is challenging since negotiations in such a context are characterised by combinatorially complex negotiation spaces, tough deadlines, very limited information about the opponents, and volatile negotiator preferences. Accordingly, practical negotiation systems should be empowered by effective learning mechanisms to acquire dynamic domain knowledge from the possibly changing negotiation contexts. This paper illustrates our adaptive negotiation agents which are underpinned by robust evolutionary learning mechanisms to deal with complex and dynamic negotiation contexts. Our experimental results show that GA-based adaptive negotiation agents outperform a theoretically optimal negotiation mechanism which guarantees Pareto optimal. Our research work opens the door to the development of practical negotiation systems for real-world applications

    Histological aspects concerning the stomach of grass snake Natrix Natrix

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    Recent studies have described the importance of snakes, in relation to their utility in several medicinal fields. However, gaps are common in the field of snake histology, which is part of the basic knowledge on these animals. Similarly, not enough information has been published on the digestive system of the grass snake (Natrix natrix). Natrix natrix was first described in 1758, by Linnaeus. It is sometimes called the ringed snake or water snake, and it belongs to Reptilia Class, Squamata Order, Serpentes Suborder, Colubridae Family, Natrix Genus. The grass snake is widely distributed in mainland Europe, northern Africa and the Middle East. It is considered one of the most common snakes in Romania. The gastric wall reveals four layers: mucosa, submucosa, muscular layer and serosa. The mucosa has projections to the lumen, similar to those of the mammals and is composed of a lining epithelium with non-ciliated simple columnar cells (cambered), lamina propria and gastric glands. Lamina propria is composed of richly vascularized connective tissue. Two categories of glands were observed: mucosal glands, located on top, made of mucosal cells, with flattened nuclei at basal pole and vacuolar cytoplasm; serous glands, located at the bottom, made of serous cells, with central spherical nuclei and intensely colored cytoplasm. The submucosa is well represented and richly vascularized. The muscle layer of the wall was composed of an inner circular, and an outer longitudinal layer. the maximum thickness is associated with the posterior area. The serosa is composed of richly vascularized and innervated connective tissue

    PROTECTED SAPROXYLIC COLEOPTERA IN "THE FORESTS IN THE SOUTHERN PART OF THE CÂNDEŞTI PIEDMONT", A ROMANIAN NATURA 2000 PROTECTED AREA

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    The observations conducted between May and October 2014 in the protected area "The Forests in the Southern part of Cândeşti Piedmont" clearly show three species of protected saproxylic beetles: Lucanus cervus, Cerambyx cerdo and Morimus asper funereus. The Quercus forests, which are dominant in that area, ensure optimal living conditions for the species L. cervus and M. asper funereus, which are common species in this site. Several aspects are presented that concern the period of activity of the individuals, sex ratio, the presence of predators and the distribution map of the species. The species C. cerdo was only found on Quercus sp, and the small number of the individuals counted in the area show that the species does not benefit from favourable development conditions. A number of pressures identified make the rational management of this protected area to be extremely important

    Sinteza, caracterizarea şi evaluarea fitobiologică a unei noi 2-[4-(4-bromofenilsulfonil) fenil]-4-metiloxazol - 5(4H)-one şi a unor noi 5-aril -2-[4-(4-bromofenilsulfonil) fenil]- 4-metiloxazoli

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    “Carol Davila“ University of Medicine and Pharmacy, Faculty of Pharmacy, Bucharest, Romania, Romanian Academy, “Costin D. Nenitescu“ Centre of Organic Chemistry, Bucharest, RomaniaPurpose. Heterocyclic compounds containing 1,3-oxazol-5(4H)-one and 1,3-oxazole ring are important targets in synthetic and medicinal chemistry, because of their applications as potentially active compounds. Thus, some 1,3-oxazol-5(4H)-ones have been reported to present antimicrobial and antitumor activity. 1,3-Oxazoles are frequent substructures in various biologically active compounds used in therapeutics as anti-inflammatory (e.g. Oxaprozin, Romazarit, Ditazol, Isamoxole), analgesic (e.g. Oxaprozin), antibacterial, antifungal (e.g. Sulfamoxole, Sulfaguanole), muscle relaxant (e.g. Azumolene) drugs. Therefore, there is considerable interest to synthesize new 1,3-oxazole- 5(4H)-ones and 1,3-oxazoles which contain 4-(4-bromophenylsulfonyl) phenyl moiety in 2 position with a hope to obtain potent biologically active compounds. The plant growth regulatory effects of the new compounds were examined. Material and Methods. By Steiger N-acylation of α-alanine with 4-(4-bromophenylsulfonyl)benzoyl chloride at cool afforded 2-[4-(4-bromophenylsulfonyl) benzamido] propanoic acid. This compound underwent intramolecular cyclization in the presence of N-methylmorpholine and ethyl chloroformate or acetic anhydride to the corresponding saturated azlactone. Then, acylaminoacylation of dry aromatic hydrocarbons (benzene, toluene, m-xylene, mesitylene) with 2-[4-(4-bromophenylsulfonyl)phenyl]-4- methyloxazol-5(4H)-one or 2-[4-(4-bromophenylsulfonyl) benzamido]propanoyl chloride in the presence of anhydrous aluminum chloride led to N-(1-aryl-1- oxopropan-2-yl)-4-(4-bromophenylsulfonyl)benzamides. These new intermediates were heterocyclized under the action of phosphorus oxychloride or concentrated sulfuric acid in the presence of acetic anhydride in ethyl acetate to the corresponding 5-aryl-2-[4- (4-bromophenylsulfonyl)phenyl]-4-methyloxazoles. The structure of new compounds was confirmed by elemental analysis and different spectral methods (FT-IR, UV, MS, 1H- and 13C-NMR). The purity of the compounds was evaluated by RP-HPLC. The new compounds have been investigated for their biological activities in the growth regulation of wheat, using the phytobiological method, known as the Constantinescu bioassay – Triticum test. Results. Ten new compounds were synthesized and characterized in orther to evaluate their biological activity. The preliminary results indicated that the tested compounds exhibited a weak stimulatory activity, except of α-acylaminoketones. Conclusions. In conclusion, in this paper we described the synthesis, characterization and phytobiological activity of ten new compounds possessing the 4-(4-bromophenylsulfonyl)phenyl moiety
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