Norditerpenoids with selective anti-cholinesterase activity from the roots of Perovskia atriplicifolia Benth

Inhibition of cholinesterases remains one of a few available treatment strategies for neurodegenerative dementias such as Alzheimer's disease and related conditions. The current study was inspired by previous data on anticholinesterase properties of diterpenoids from Perovskia atriplicifolia and other Lamiaceae species. The acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibition by the three new natural compounds-(1R,15R)-1-acetoxycryptotanshinone (1), (1R)-1-acetoxytanshinone IIA (2), and (15R)-1-oxoaegyptinone A (3)-as well as, new for this genus, isograndifoliol (4) were assessed. Three of these compounds exhibited profound inhibition of butyrylcholinesterase (BChE) and much weaker inhibition of acetylcholinesterase (AChE). All compounds (1-4) selectively inhibited BChE (IC(50) = 2.4, 7.9, 50.8, and 0.9 µM, respectively), whereas only compounds 3 and 4 moderately inhibited AChE (IC(50) 329.8 µM and 342.9 µM). Molecular docking and in silico toxicology prediction studies were also performed on the active compounds. Natural oxygenated norditerpenoids from the traditional Central Asian medicinal plant P. atriplicifolia are selective BChE inhibitors. Their high potential makes them useful candidate molecules for further investigation as lead compounds in the development of a natural drug against dementia caused by neurodegenerative diseases

Evaluation of the properties of polymer composites with carbon nanotubes in the aspect of their abrasive wear

Purpose: Carbon nanotubes are used in composite materials due to the improvement of (including tribological) properties of composites, especially thermoplastic matrix composites. This demonstrates the potential of CNTs and the validity of research on determining the impact of this type of reinforcement on the composite materials under development. Design/methodology/approach: The article presents selected results of research on polymer composites made of C.E.S. R70 resin, C.E.S. H72 hardener with the addition of a physical friction modifier (CNTs) with a percentage by volume of 18.16% and 24.42%, respectively, which also acts as a reinforcement. The produced material was subjected to hardness measurements according to the Shore method and EDS analysis. The study of abrasive wear in reciprocating movement was carried out using the Taber Linear Abraser model 5750 tribotester and a precision weight. The surface topography of the composite material after tribological tests was determined using scanning electron microscopy (SEM). Some of the mentioned tests were carried out on samples made only of resin, used as the matrix of the tested polymer composite. Findings: Carbon nanotubes used in polymer matrix composites, including bisphenol A/F epoxy resin have an influence on the tribological properties of the material. The addition of carbon nanotubes contributed to a 24% increase in the Ra parameter relative to pure resin, to a level corresponding to rough grinding of steel. Research limitations/implications: The results of the tests indicate the need to continue research in order to optimize the composition of composites in terms of operating parameters of friction nodes in broadly understood aviation. Originality/value: The analysed literature did not find any studies on the impact of the addition of carbon nanotubes on epoxy resins based on bisphenol A/F. Due to the wide scope of application of such resins, the properties of such composite materials in which carbon nanotubes are the reinforcing phase have been investigated

Changing optical and electrical parameters of laser diodes (LDs) emitting at 808 nm and 880 nm during continuous operation

Zaprezentowane zostały zmiany parametrów optycznych i elektrycznych diod podczas długotrwałej pracy: zmniejszenie mocy wyjściowej, zwiększenie prądu progowego jak i zmiana długości fali emisji - dla diod na pasmo 880 nm w kierunku fal krótszych oraz dla diod na pasmo 808 nm w kierunku fal dłuższych.The following changes in optical and electrical parameters for diodes during long-term operation are presented: reduction in the output power, increase in the threshold current and change in the emission wavelength for diodes emitting at 880 nm towards shorter wavelengths and for diodes emitting at 808 nm towards longer wavelengths

Oil and gas in Poland : prospects and licensing rounds in 2018 in terms of hydrocarbon concessions (part I)

On the 28th of June 2017, the Polish Ministry of the Environment announced the boundaries of the tender areas selected for the third licensing round for concessions for prospection, exploration and exploitation of hydrocarbons. This round is going to be proceeded in the 4th Quarter of 2018 and 1st Quarter of 2019. The geologists of the Polish Geological Survey selected 15 tender areas (promising for discoveries of conventional and unconventional oil and gas fields) based on the geological data resources stored in the National Geological Archive, other published data, as well as the knowledge and experience of employees of the Polish Geological Institute - National Research Institute and the Polish Ministry of the Environment. All selected areas are located onshore. In this article we describe 10 tender areas located in the Gdańsk, Pomerania and Wielkopolska petroleum provinces. Other tender areas situated in the Carpathians (Błażowa, Proszowice W, Rudnik-Lipiny, Wetlina) and in the Lublin Petroleum Province (Ryki) will be discussed in the next publication. Three areas: Wejherowo, Bytów and Braniewo-Miłakowo are located in the northern Poland (Gdańsk Petroleum Province). The exploration targets of these areas are generally related to structural-lithological traps in the Middle Cambrian beds of the Baltic Basin, as well as to unconventional shale oil and gas in the Lower Paleozoic. Seven tender areas are situated in the northwestern Poland (Pomerania and Wielkopolska Petroleum Provinces). Three of them - Chodzież, Piła and Leszno are dedicated to conventional gas deposits in the Rotliegend sandstones and, in some cases, also oil deposits in the Zechstein/Main Dolomite. Excluding the Leszno tender area, chances for tight gas discoveries exist within the Rotliegend sandstones. The exploration target of the Konin tender area is related to possible conventional fields in the Jurassic and Lower Cretaceous beds. In the Pomerania region the exploration target is generally related to conventional hydrocarbon deposits in the Devonian, Carboniferous and Permian (Rotliegend and Zechstein/Main Dolomite). Three tender areas are situated within the region of: Sierpowo, Orle and Chełmno. As a rule, a concession is granted for a period of 10 to 30 years and is divided into 2 phases: 1) prospecting and exploration phase (which lasts from 4 to 5 years and can be extended to another 2-year period), 2) production phase. Every entity interested in obtaining a concession needs to undergo the qualification procedure. We believe that this publication will contribute to better understanding of the offered tender areas and encourage activity in the Polish oil and gas sector