Search results for "ASYM"

Don't tell us: the demand for secretive bahaviour

2009

International audience

Nuclear Dependence of the Transverse-Single-Spin Asymmetry for Forward Neutron Production in Polarized p+A Collisions at √sNN = 200 GeV

2018

During 2015, the Relativistic Heavy Ion Collider (RHIC) provided collisions of transversely polarized protons with Au and Al nuclei for the first time, enabling the exploration of transverse-single-spin asymmetries with heavy nuclei. Large single-spin asymmetries in very forward neutron production have been previously observed in transversely polarized p + p collisions at RHIC, and the existing theoretical framework that was successful in describing the single-spin asymmetry in p + p collisions predicts only a moderate atomic-mass-number ( A ) dependence. In contrast, the asymmetries observed at RHIC in p + A collisions showed a surprisingly strong A dependence in inclusive forward neutron …

Organocatalytic Enantioselective Vinylogous Henry Reaction of 3,5-Dimethyl-4-nitroisoxazole with Trifluoromethyl Ketones

2017

The enantioselective vinylogous Henry reaction of 3,5-dimethyl-4-nitroisoxazole with trifluoromethyl ketones employing a bifunctional squaramide organocatalyst has been developed. A series of isoxazole bearing trifluoromethyl-substituted tertiary alcohols, 2-substituted (R)-1,1,1-trifluoro-3-(3-methyl-4-nitroisoxazol-5-yl)propan-2-ols, were obtained under these mild reaction conditions in good yields and moderate to good enantioselectivities

Large number asymptotics of two-component systems

2012

We shall analyze the asymptotics of two-component systems with at least one particle component when the number of particles becomes large; choosing suitable scalings for the parameters, we find the set of coupled partial differential equations modeling those systems in the limit.

Asymmetrical muscle strength deficit, mobility limitation and aquatic resistance training in persons with knee osteoarthritis

2013

Endophytic Fungi in Asymptomatic Vitis vinifera L. and their Effects on Plasmopara viticola

2016

During a multi-year study on the life cycle of Plasmopara viticola to assess the typical epidemiology of downy mildew on grapevine (Vitis vinifera) in west Sicily (Italy), several leaves on which the downy mildew had collapsed were found and observed in a vineyard located in Marsala, in Trapani Province. An antagonistic fungus was isolated from these leaves and named A20; through its morphology, it was identified as a hyphomycete belonging to the genus Acremonium. The antagonism of A20 against the asexual and sexual spores of P. viticola, as well as endophytic nature of the genus Acremonium in V. vinifera were confirmed by further studies which have been carried out over the past decade. In…

Water in stereoselective organocatalytic reactions

2009

In this review, recent advances in asymmetric organocatalytic reactions carried out with variable amounts of water, from substoichiometric to a large excess (reaction medium), are discussed. We also summarize several proposed mechanisms for the different possibilities of the action of water both in the increased activity of the catalyst and in the asymmetric induction. Finally, the application of this catalytic methodology to the enantioselective synthesis of valuable compounds through enamine or iminium catalysis is presented.

Measurement of parity-violating spin asymmetries in W± production at midrapidity in longitudinally polarized p+p collisions

2016

We present midrapidity measurements from the PHENIX experiment of large parity-violating singlespin asymmetries of high transverse momentum electrons and positrons from W =Z decays, produced in longitudinally polarized p þ p collisions at center of mass energies of ffiffi s p ¼ 500 and 510 GeV. These asymmetries allow direct access to the antiquark polarized parton distribution functions due to the parityviolating nature of the W-boson coupling to quarks and antiquarks. The results presented are based on data collected in 2011, 2012, and 2013 with an integrated luminosity of 240 pb−1, which exceeds previous PHENIX published results by a factor of more than 27. These high Q2 data probe the p…

Wpływ związków fosfonowych na zawartość barwników asymilacyjnych w komórkach cyjanobakterii

2013

Desymmetrization of Prochiral Cyclobutanones via Nitrogen Insertion: A Concise Route to Chiral γ‐Lactams

2021

Abstract Asymmetric access to γ‐lactams is achieved via a cyclobutanone ring expansion using widely available (1S,2R)‐1‐amino‐2‐indanol for chiral induction. Mechanistic analysis of the key N,O‐ketal rearrangement reveals a Curtin–Hammett scenario, which enables a downstream stereoinduction (up to 88:12 dr) and is corroborated by spectroscopic, crystallographic, and computational studies. In combination with an easy deprotection protocol, this operationally simple sequence allows the synthesis of a range of optically pure γ‐lactams, including those bearing all‐carbon quaternary stereocenters. In addition, the formal synthesis of drug molecules baclofen, brivaracetam, and pregabalin further …