Nature has exploited medium-sized 8- to 11-membered rings in a variety of natural products to address diverse and challenging biological targets. However, owing to the limitations of conventional cyclization-based approaches to medium-ring synthesis, these structures remain severely underrepresented in current probe and drug discovery efforts. To address this problem, we have established an alt...

this paper is concerned with the surface and small scale effects on transverse vibration of a viscoelastic single-layered graphene sheet (slgs) subjected to an in-plane magnetic field. the slgs is surrounded by an elastic medium which is simulated as visco-pasternak foundation. in order to investigate the small scale effects, the nonlocal elasticity theory is employed due to its simplicity and ...

Background: In vitro maturation (IVM) of immature oocyte is a promising treatment option for infertile women.IVM procedures attempt to mimic the natural conditions of the follicular environment. The technique of IVM of oocytes has been successful after the first trial using culture of human oocytes in follicular fluid. The crucial part of this technique is the maturation process itself, and the...

fars province is one of the natural habitats of pyrus species in iran. harvesting of fruits, deforestation, expansion of agriculture and overgrazing in recent years has threatened the wild pear open forests and imposed detrimental effects on their natural regeneration, therefore, investigation on propagation of wild pear species for afforestation is needed. this research was carried out to deve...

in ordet to investigate economic efficiency of five cultural systems in sugar beet crop, including high input, medium input  low input , high  and medium inputs without 3 times irrigation after emergence, an experiment was conducted over  two years  (2002-2003) in agricultural and natural resources research center of khorasan. these systems were analysed by marginal analysis and  linear program...

Our concepts of biology, evolution and complexity are constrained by having observed only a single instance of life, life on Earth. A truly comparative biology is needed to extend these concepts. Because we can not observe life on other planets, we are left with the alternative of creating artificial life forms on Earth. I will discuss the approach of inoculating evolution by natural selection ...

To develop an alternative method for production of sarsasapogenin by plant tissue culture technique and its quantification in Asparagus racemosus and its in vitro cultures using HPTLC. Murashige and Skoog’s (MS) basal medium supplemented with various growth regulators was used for development of shoot and root calli while, hormone free MS medium was used for development of Agrobacterium tumefac...