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Tactical substitutions

Thomas C Nugent, Foad Tehrani Najafian, Hussein Ali El Damrany Hussein, Ishtiaq Hussain
Site selectivity, differentiating instances of the same functional group type on one substrate, represents a forward-looking theme within chemistry: reduced dependence on protection/deprotection protocols for increased overall yield and step-efficiency. Despite these potential benefits and the expanded tactical advantages afforded to synthetic design, site selectivity remains elusive and especially so for ketone-based substrates. Herein, site-selective intermolecular mono-aldolization has been demonstrated for an array of prochiral 4-keto-substituted cyclohexanones with concomitant regio-, diastereo-, and enantiocontrol...
September 26, 2016: Chemistry: a European Journal
Evelyn Hearne, Marie Claire Van Hout
An array of dissociative novel psychoactive substances, including "methoxetamine," "3-MeO-PCP," and "methoxphenidine," have emerged as substitutes for the illicit substance "ketamine." A netographic research methodology aimed to describe online, dissociative novel psychoactive substance users' perceptions of risk, informed knowledge around use, and indigenous harm-reduction practices as advocated within online drug fora, so as to provide credible information which can be used to inform public online health education and drug prevention...
September 2016: Journal of Psychoactive Drugs
Liam D Harper, Melissa Fothergill, Daniel J West, Emma Stevenson, Mark Russell
Qualitative research investigating soccer practitioners' perceptions can allow researchers to create practical research investigations. The extra-time period of soccer is understudied compared to other areas of soccer research. Using an open-ended online survey containing eleven main and nine sub questions, we gathered the perceptions of extra-time from 46 soccer practitioners, all working for different professional soccer clubs. Questions related to current practices, views on extra-time regulations, and ideas for future research...
2016: PloS One
Yu Feng, Jun Liu, Yazmin P Carrasco, John B MacMillan, Jef K De Brabander
We describe the isolation, structure elucidation, and total synthesis of the novel marine natural product rifsaliniketal and the total synthesis of the structurally related variants salinisporamycin and saliniketals A and B. Rifsaliniketal was previously proposed, but not observed, as a diverted metabolite from a biosynthetic precursor to rifamycin S. Decarboxylation of rifamycin provides salinisporamycin, which upon truncation with loss of the naphthoquinone ring leads to saliniketals. Our synthetic strategy hinged upon a Pt(II)-catalyzed cycloisomerization of an alkynediol to set the dioxabicyclo[3...
June 8, 2016: Journal of the American Chemical Society
Martin Pettersson, Xinjun Hou, Max Kuhn, Travis T Wager, Gregory W Kauffman, Patrick R Verhoest
Strategic replacement of one or more hydrogen atoms with fluorine atom(s) is a common tactic to improve potency at a given target and/or to modulate parameters such as metabolic stability and pKa. Molecular weight (MW) is a key parameter in design, and incorporation of fluorine is associated with a disproportionate increase in MW considering the van der Waals radius of fluorine versus hydrogen. Herein we examine a large compound data set to understand the effect of introducing fluorine on the risk of encountering P-glycoprotein mediated efflux (as measured by MDR efflux ratio), passive permeability, lipophilicity, and metabolic stability...
June 9, 2016: Journal of Medicinal Chemistry
A Nazemi, J Khajehali, T Van Leeuwen
Onion thrips, Thrips tabaci Lindeman, is the main pest of onion-growing fields in Isfahan and is mainly controlled by frequently spraying several insecticides. To investigate the resistance status and mechanisms, the susceptibility of ten field populations collected from Isfahan onion-growing regions were tested to several currently used pesticides. Resistance to the tested insecticides was observed in most populations when compared with the susceptible reference population. Enhanced detoxification, implicated by the use of inhibitors of major metabolic detoxification enzymes, was observed in the populations resistant to profenofos and chlorpyrifos...
May 2016: Pesticide Biochemistry and Physiology
Vladimir Ilic, Igor Ranisavljev, Dorde Stefanovic, Vuk Ivanovic, Vladimir Mrdakovic
The purpose of the study was to determine the morphological and functional characteristics of 32 Serbian national U20 handball players (age 20.43 +/- 1.16 y; training experience 8.12 +/- 1.89 y) before European championship in Switzerland (2006) and to determinate their impact on competitive performance and outstanding success achieved. The results show that wing players differ from other players in morphological characteristics. Values for body height, weight, BMI, muscle mass and fat mass were significantly lower compared to the other playing positions...
September 2015: Collegium Antropologicum
A Mabbott, D J Carr, S Champion, C Malbon
Tissue simulants are typically used in ballistic testing as substitutes for biological tissues. Many simulants have been used, with gelatine amongst the most common. While two concentrations of gelatine (10 and 20 %) have been used extensively, no agreed standard exists for the preparation of either. Comparison of ballistic damage produced in both concentrations is lacking. The damage produced in gelatine is also questioned, with regards to what it would mean for specific areas of living tissue. The aim of the work discussed in this paper was to consider how damage caused by selected pistol and rifle ammunition varied in different simulants...
September 2016: International Journal of Legal Medicine
(no author information available yet)
The Collegium Ramazzini reaffirms its long-standing position that responsible public health action is to ban all extraction and use of asbestos, including chrysotile. This current statement updates the Collegium's earlier statements with a focus on global health dimensions of asbestos and asbestos-related diseases (ARD). The ARD epidemic will likely not peak for at least a decade in most industrialized countries and for several decades in industrializing countries. Asbestos and ARD will continue to present challenges in the arena of occupational medicine and public health, as well as in clinical research and practice, and have thus emerged as a global health issue...
January 2016: Scandinavian Journal of Work, Environment & Health
Mathieu Lacome, Julien Piscione, Jean-Philippe Hager, Christopher Carling
PURPOSE: The patterns and performance of substitutions were investigated in 18 international 15-a-side male rugby union matches. METHODS: A semi-automatic computerised time-motion system compiled 750 performance observations (forwards=422, backs=328) for 375 players. Running and technical performance measures included total distance run, high-intensity running (runs >18.0km.h-1), number of individual ball possessions and passes, percentage of passes completed and number of attempted and percentage of successful tackles...
December 14, 2015: International Journal of Sports Physiology and Performance
Kåre B Jørgensen, Toni Rantanen, Thilo Dörfler, Victor Snieckus
A general, efficient, and regioselective synthesis of a series of hydroxylated 1-methylphenanthrenes 9 by a combined directed ortho metalation (DoM)-Suzuki-Miyaura cross-coupling-directed remote metalation (DreM) sequence is reported. Diversity to this methodology was achieved by a regioselective DoM rather than DreM reaction, affording more highly substituted phenanthrols ( Table 2 ). Application of the turbo-Grignard reagent (i-PrMgCl·LiCl) in the Ni-catalyzed Corriu-Kumada reaction gave efficient decarbamoylation ( Tables 3 and 4 )...
October 2, 2015: Journal of Organic Chemistry
Lorenzo Caruana, Mariafrancesca Fochi, Luca Bernardi
Quinone methides (QMs) are highly reactive compounds that have been defined as "elusive" intermediates, or even as a "synthetic enigma" in organic chemistry. Indeed, there were just a handful of examples of their utilization in catalytic asymmetric settings until some years ago. This review collects organocatalytic asymmetric reactions that employ QMs as substrates and intermediates, from the early examples, mostly based on stabilized QMs bearing specific substitution patterns, to more recent contributions, which have dramatically expanded the scope of QM chemistry...
2015: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
Konstantin Press, Israel Goldberg, Moshe Kol
Alkyl aluminum complexes of chiral salan ligands assembled around the 2,2'-bipyrrolidine core form as single diastereomers that have identical configurations of the N donors. Active catalysts for the polymerization of lactide were formed upon the addition of benzyl alcohol. Polymeryl exchange between enantiomorphous aluminum species had a dramatic effect on the tacticity of the poly(lactic acid) (PLA) in the polymerization of racemic lactide (rac-LA): The enantiomerically pure catalyst of the nonsubstituted salan ligand led to isotactic PLA, and the racemic catalyst exhibited lower stereocontrol...
December 1, 2015: Angewandte Chemie
Rebecca J Williams, Rebecca Knight
Electronic cigarettes (e-cigarettes) are an emerging phenomenon that is becoming increasingly popular among adolescents. Current e-cigarette use among adolescents has more than doubled in the past few years nationally and more than tripled in Hawai'i, despite the fact that safety in terms of health and injury from use is widely unknown. The use of e-cigarettes among adolescents is of particular concern because they may act as a gateway to smoking conventional tobacco cigarettes, substitute for cigarettes where smoking would normally not be allowed, and weaken the effect of clean air policies, and displace effective smoking cessation treatments...
February 2015: Hawai'i Journal of Medicine & Public Health: a Journal of Asia Pacific Medicine & Public Health
Lara C Czabaniuk, Timothy F Jamison
A new and highly selective method for the synthesis of hydroxyl-substituted tetrahydropyrans is described. This method utilizes titanium(IV) isopropoxide and diethyl tartrate to perform a diastereoselective epoxidation followed by in situ epoxide activation and highly selective endo-cyclization to form the desired tetrahydropyran ring. The HIJ ring fragment of the marine ladder polyether yessotoxin was synthesized using this two-stage tactic that proceeds with high efficiency and excellent regioselectivity.
February 20, 2015: Organic Letters
Yukika Wada, Hiroaki Kusano, Tomohiko Tsuge, Takashi Aoyama
Plants drastically alter their root system architecture to adapt to different underground growth conditions. During phosphate (Pi) deficiency, most plants including Arabidopsis thaliana enhance the development of lateral roots and root hairs, resulting in bushy and hairy roots. To elucidate the signal pathway specific for the root hair elongation response to Pi deficiency, we investigated the expression of type-B phosphatidylinositol phosphate 5-kinase (PIP5K) genes, as a quantitative factor for root hair elongation in Arabidopsis...
February 2015: Plant Journal: for Cell and Molecular Biology
Andrea R Beyer, Hilary K Truchan, Levi J May, Naomi J Walker, Dori L Borjesson, Jason A Carlyon
SUMOylation, the covalent attachment of a member of the small ubiquitin-like modifier (SUMO) family of proteins to lysines in target substrates, is an essential post-translational modification in eukaryotes. Microbial manipulation of SUMOylation recently emerged as a key virulence strategy for viruses and facultative intracellular bacteria, the latter of which have only been shown to deploy effectors that negatively regulate SUMOylation. Here, we demonstrate that the obligate intracellular bacterium, Anaplasma phagocytophilum, utilizes an effector, AmpA (A...
April 2015: Cellular Microbiology
Christopher Carling, Franck Le Gall, Alan McCall, Mathieu Nédélec, Gregory Dupont
Squad management, injury and physical, tactical and technical match performance were investigated in a professional soccer team across five consecutive league seasons (2008-2013, 190 league games) with specific focus on a championship-winning season (2010/11). For each player, match participation and time-loss injuries were recorded, the latter prospectively diagnosed by the team's physician. Defending and attacking tactical and technical performance indicators investigated included ball possession and possession in opponents' half, passes, forward passes, completed passes and forward passes, crosses and completed crosses, goal attempts and goal attempts on target, successful final third entries, free-kicks and 50/50 duels won/lost...
2015: European Journal of Sport Science
Ayellet Stopper, Konstantin Press, Jun Okuda, Israel Goldberg, Moshe Kol
Sequential tetradentate dianionic thio-imine diphenolate ligands featuring an ortho-phenylene core and their zirconium complexes are described for the first time. Ligands that include different combinations of bulky-alkyl groups and halo groups on the two phenol arms were prepared by a substitution/condensation reaction sequence. An unexpected fac-fac wrapping mode was found in the solid state for the ligands in the octahedral [{ONSO}Zr(O(t)Bu)2] complexes. The complexes were all fluxional, and the barrier for enantiomer interconversion was found to depend on the phenolate substituents...
September 2, 2014: Inorganic Chemistry
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