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Juan García de la Concepción, Martín Ávalos, Pedro Cintas, José L Jiménez, Mark E Light
A mesoionic bicycle, easily synthesized from a proteinogenic amino acid, l-leucine, behaves as both thiazolium-olate and diazolium-olate dipoles, as unveiled by its dipolar cycloadditions. This chameleonic reactivity has been thoroughly interpreted by dissecting the mechanistic landscape aided by the distortion-interaction model.
June 15, 2018: Organic & Biomolecular Chemistry
R P Saunders, M Dowda, K McIver, R R Pate
BACKGROUND: Physical activity helps prevent excessive weight gain in youth. Few studies have examined regional variations in common activities, walking and bicycling. OBJECTIVE: The primary aim was to examine participation in previous 7-day walking/bicycling for active transport and for fun/exercise by region, gender and age groups. METHODS: Children (n = 2693) from 130 diverse, geographically distributed US communities reported participation in previous 7-day walking/bicycling...
June 14, 2018: Pediatric Obesity
Torey M Anderson, Kaitlynn L McKirgan, Jennifer D Hastings
Study design: The primary study design was a pretest and posttest study performed in a single session with subjects as their own control. We summarize three integrated and sequential studies. Objective: The objective of this study was to investigate whether commercially available cushioned shorts would add skin protection when used in adaptive sports equipment (AE). Setting: Community in Tacoma Washington, USA. Methods: TekScan Pressure Mapping System for recording average (AP) and peak (PP) seating pressures...
2018: Spinal Cord Series and Cases
Melissa Mariti Fraga, Maria Teresa Terreri, Rafael Teixeira Azevedo, Maria Odete Esteves Hilário, Claudio Arnaldo Len
OBJECTIVE: To measure and compare musculoskeletal pain in patients with juvenile fibromyalgia (JFM) and polyarticular juvenile idiopathic arthritis (JIA), and to evaluate and compare pain perception and pain coping mechanisms in these patients. METHODS: In this cross sectional study, we evaluated 150 children and adolescents, and their respective parents, from 3 different groups: JFM, polyarticular JIA, and healthy controls. Pain intensity and pain coping mechanisms were measured using specific questionnaires...
June 11, 2018: Revista Paulista de Pediatria: Orgão Oficial da Sociedade de Pediatria de São Paulo
Jeffrey S Cannon
An enantioselective route to the C,D-bicycle of massadine is reported. Enantiopure intermediates were generated by a single stereoselective reduction using the Corey-Bakshi-Shibata reagent. This initial stereoinduction was translated into the five contiguous stereocenters of the massadine D-ring by a synthetic route that features a diastereoselective and stereospecific Ireland-Claisen rearrangement of a trianionic enolate followed by a diastereoselective nitrone dipolar cycloaddition of a highly electron-poor oxime...
June 13, 2018: Organic Letters
Bart Jelijs, Joost Heutink, Dick de Waard, Karel A Brookhuis, Bart J M Melis-Dankers
PURPOSE: This study aims to identify the most important factors that influence the independent bicycle use of visually impaired people in the Netherlands. MATERIALS AND METHODS: Both visually impaired people and professionals participated in a two-round online Delphi study (n = 42). In Round 1 the participants identified the factors which they ranked by relevance in Round 2. RESULTS: The participants prioritised environmental factors related to the traffic situation, the characteristics of the infrastructure, and weather and light conditions (Kendall's W = 0...
June 12, 2018: Disability and Rehabilitation
Maciej Malinowski, Raphaël Hensienne, Nicolas Kern, Damien Tardieu, Anne Bodlenner, Damien Hazelard, Philippe Compain
We report herein the development of a stereodivergent route towards polyhydroxylated bicyclic azetidine scaffolds, namely 6-azabicyclo[3.2.0]heptane derivatives. The strategy hinges on a common bicyclic β-lactam precursor, which is forged by way of a rare example of a cationic Dieckmann-type reaction, followed by IBX-mediated desaturation. Substrate-controlled diastereoselective oxidations then allow the divergent preparation of novel iminosugar mimics.
June 12, 2018: Organic & Biomolecular Chemistry
Sergio A Useche, Luis Montoro, Francisco Alonso, Francisco M Tortosa
INTRODUCTION: While the use of bicycles as mean of transport is growing worldwide, the increasing rates of traffic crashes involving cyclists have turned into a relevant scientific, public health, and road safety concern. According to several studies, and despite the fact that some countries are taking part in preventive actions, the data indicate that the problem of cycling injuries implies high costs for the community welfare, for the economy, and for healthcare systems, thus proving a clear need for solutions...
June 7, 2018: Accident; Analysis and Prevention
Cheng Zhang, Sailan Chang, Shanliang Dong, Lihua Qiu, Xinfang Xu
An unprecedented transition-metal-free tandem bicyclization of diaryl alkynes has been disclosed, which provides a streamlined access to a range of polycyclic 2H-indazoles in high to excellent yields. The salient features of this reaction include readily available starting materials, good functional group compatibility, mild reaction conditions, no column chromatography, high bond-formation efficiency, and ease in further transformations. Notably, this is the first example for the synthesis of 2H-indazoles with in situ generated diazonium salt as the nitrogen source, and a mechanistic rationale involving an acid-promoted tandem diazonium salt formation/bicyclization process is discussed...
June 8, 2018: Journal of Organic Chemistry
Lena Decuyper, Sari Deketelaere, Lore Vanparys, Marko Jukic, Izidor Sosic, Eric Sauvage, Ana Maria Amoroso, Olivier Verlaine, Bernard Joris, Stanislav Gobec, Matthias D'hooghe
As a complement to the renowned bicyclic beta-lactam antibiotics, monocyclic analogues provide a breath of fresh air in the battle against resistant bacteria. In that framework, the present study discloses the in silico design and unprecedented ten-step synthesis of eleven nocardicin-like enantiomerically pure 2-{3-[2-(2-aminothiazol-4-yl)-2-(methoxyimino)acetamido]-2-oxoazetidin-1-yl}acetic acids starting from serine as a readily accessible precursor. The capability of this novel class of monocyclic 3-amino-beta-lactams to inhibit penicillin-binding proteins (PBPs) of various (resistant) bacteria was assessed, revealing the potential of alfa-benzylidenecarboxylates as interesting leads in the pursuit of novel PBP inhibitors...
June 8, 2018: Chemistry: a European Journal
Tomonori Shibata, Kazuhiko Nakatani
We have reported bicyclic and tricyclic C-C mismatch-binding ligands that selectively bind to CCG trinucleotide repeat (TNR) DNAs. Bivalent interaction and enlarging the aromatic ring system of the cytosine-recognition unit led to the ligand binding to CCG TNRs accompanied by the formation of stable ligand-CCG TNR complexes and a large conformational change.
June 7, 2018: Chemical Communications: Chem Comm
Eva Krauzová, Petr Tůma, Isabelle de Glisezinski, Vladimír Štich, Michaela Šiklová
Objective: Metformin was shown to exert an antilipolytic action in adipose tissue (AT) that might mediate beneficial effects on lipid metabolism in diabetic patients. However, during exercise, the inhibition of induced lipolysis in AT would limit the energy substrate supply for working muscle. Thus, the aim of this study was to investigate whether metformin exerts inhibitory effect on exercise-induced lipolysis in subcutaneous adipose tissue (SCAT) (Moro et al., 2007) in humans. Approach: Ten healthy lean men underwent two exercise sessions consisting of 60 min of cycling on bicycle ergometer combined with (a) orally administered metformin and (b) metformin locally administered into SCAT...
2018: Frontiers in Physiology
Marc H Garner, Haixing Li, Yan Chen, Timothy A Su, Zhichun Shangguan, Daniel W Paley, Taifeng Liu, Fay Ng, Hexing Li, Shengxiong Xiao, Colin Nuckolls, Latha Venkataraman, Gemma C Solomon
The tunnelling of electrons through molecules (and through any nanoscale insulating and dielectric material 1 ) shows exponential attenuation with increasing length 2 , a length dependence that is reflected in the ability of the electrons to carry an electrical current. It was recently demonstrated3-5 that coherent tunnelling through a molecular junction can also be suppressed by destructive quantum interference 6 , a mechanism that is not length-dependent. For the carbon-based molecules studied previously, cancelling all transmission channels would involve the suppression of contributions to the current from both the π-orbital and σ-orbital systems...
June 6, 2018: Nature
Guido Furlotti, Maria Alessandra Alisi, Nicola Cazzolla, Beatrice Garrone, Gabriele Magarò, Giorgina Mangano, Marco Vitiello, Francesca Ceccacci, Tecla Gasperi, Angela La Bella, Francesca Leonelli, Maria Antonietta Loreto, Emanuela Masini, Rinaldo Marini Bettolo, Martina Miceli, Luisa Maria Migneco
Glaucoma affects millions of people worldwide, causing optic nerve damage and blindness. The elevation of the intraocular pressure (IOP) is the main risk factor associated with this pathology, and nowadays, the key therapeutic target of the existing pharmacological treatments. We studied, as potential ocular hypotensive agents, compounds acting on two receptors (serotonin 2A, 5-HT2A, and adrenergic α1) linked to the regulation of the humour aqueous dynamic. In this article we describe the design, synthesis, and pharmacological profiling of a series of novel bicyclic and tricyclic 2N-alkyl-indazole-amide derivatives...
June 6, 2018: ChemMedChem
Feng Li, Peng Hu, Mingming Sun, Chunju Li, Xueshun Jia, Jian Li
An unusual cascade reaction of isocyanide and enynone using Yb/Ag cooperative catalysis as a key step has been disclosed. The present strategy enables the double isocyanide insertion and subsequent 5-endo-dig cyclization, thus providing a quick access to structurally complex pyrrole-fused heterocycles.
June 6, 2018: Chemical Communications: Chem Comm
Christina Valle, Anja Hirschmüller, Marcus Schmitt-Sody, Bernhard Haller, Matthias Keller, Wolfgang Schoch, Helmut Hoffman, Philipp Minzlaff
INTRODUCTION:  Rehabilitation protocols following anterior cruciate ligament (ACL) reconstruction often differ among orthopaedic surgeons. The primary aim of this study was to investigate which follow-up treatment is recommended by "AGA instructors" certified by the German-speaking Association for Arthroscopic and Open Joint Surgery (AGA). The secondary aim was to compare these findings with the current literature. MATERIAL AND METHODS:  A structured anonymous online survey was performed with "AGA instructors" specialised in knee or ACL surgery...
June 2018: Sportverletzung Sportschaden: Organ der Gesellschaft Für Orthopädisch-Traumatologische Sportmedizin
Xinyue Hu, Yuhang Zhou, Yan Lu, Sijia Zou, Lili Lin, Xiaohua Liu, Xiaoming Feng
A highly efficient enantioselective inverse-electron-demand hetero-Diels‒Alder reaction of dioxopyrrolidines with hetero-substituted alkenes has been realized by using a N,N'-dioxide/Ni(II) complex as catalyst. A series of chiral bicyclic dihydropyranes were generated in excellent yields, good dr and excellent ee values. Besides, a catalytic cycle with a possible transition state was proposed.
June 5, 2018: Journal of Organic Chemistry
Anna Sofie Larsen, Frederik G Larsen, Frederik F Sørensen, Mathias Hedegaard, Nicolai Støttrup, Ernst A Hansen, Pascal Madeleine
The objectives were 1) to design and produce two novel unpadded bicycle saddles with a wide/medium width and partial nose cutout; 2) to investigate the responses on pressure distribution and perceived discomfort in female cyclists. For comparison, a standard saddle was also tested. Nineteen female cyclists pedaled on an ergometer cycle for 20 min with each saddle in a counterbalanced order. A pressure mat measured saddle interface pressure. Discomfort ratings were collected using a visual analogue scale. Total mean saddle pressure remained similar across saddles...
July 2018: Applied Ergonomics
Menna A Ewida, Dalal A Abou El Ella, Deena S Lasheen, Heba A Ewida, Yomna I El-Gazzar, Hussein I El-Subbagh
New series of thiazolo[4,5-d]pyridazin and imidazo[2',1':2,3]thiazolo[4,5-d]pyridazin analogues were designed, synthesized and evaluated for their invitro DHFR inhibition and antitumor activity. Compounds 13 and 43 proved to be DHFR inhibitors with IC50 0.05 and 0.06 μM, respectively. 43 proved lethal to OVCAR-3 Ovarian cancer and MDA-MB-435 Melanoma at IC50 0.32 and 0.46 μM, respectively. The active compounds formed hydrogen bond at DHFR binding site between N1 -nitrogen of the pyridazine ring with Glu30; the carbonyl group with Trp24, Arg70 or Lys64; π-cation interaction with Arg22 and π-π interaction with Phe31 residues...
May 26, 2018: Bioorganic Chemistry
Jun-Ping Pei, Ying-Han Chen, Yan-Kai Liu
Structurally complex cyclic hemiacetals bearing a racemic tetrasubstituted stereocenter have been prepared in a concise manner and were successfully used in an organocatalytic enantioselective sequence to react with functionalized nitro-olefins, providing bicyclic acetal-containing compounds as two separable epimers with excellent stereoselectivity. The reaction showed broad substrate scope, with respect to the starting hemiacetals. Moreover, this protocol allows the synthetic transformation of the products to various interesting heterocyclic compounds with substantial structural diversity and broad functionality...
June 4, 2018: Organic Letters
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