166 research outputs found
Neuromuscular and functional responses to concentric and eccentric strength training in older adults: A systematic review
The type of muscle action is important when designing exercise interventions for older individuals and may result in different effects. In this study we performed a systematic review of controlled trials comparing the effects of concentric and eccentric resistance training, performed on isokinetic dynamometers, on lower extremity muscular and functional performance in older adults (CDR42017075316). Six databases (Pubmed, CINAHL, SPORTDiscus, PEDro, Cochrane Central, and Embase) were searched. Outcomes of interest concerned neuromuscular and functional performance. Trials should consider 65 years or older individuals participating in concentric and/or eccentric training on isokinetic dynamometers, at least twice a week, during at least four weeks. Results should be compared to a control group or between different contraction types. A qualitative analysis of data was done. Quality assessment considered the Cochrane Risk of Bias Tool. The initial search returned 10376 studies and four trials were considered for inclusion. Three trials compared the effects of concentric training with the ones of control groups, and one compared the effects of concentric with the ones of eccentric training. All trials focused on knee extensor and flexor muscles, and one also focused on ankle dorsiflexors and plantarflexors. Training programs included three sessions/week lasting 8-12 weeks. Concentric training improved strength, power, and muscle antagonist coactivation compared to the control. Concentric and eccentric training improved knee isometric, concentric and eccentric strength and scores on self-paced step test, with no effect on gait speed. They did not consider muscle structural parameters. The findings of beneficial effects of isokinetic concentric and eccentric resistance training on muscle strength and power in older adults were consistent. However, there is a lack of trials addressing the effects of isokinetic strength training on muscle structure and functionality
1-[(Z)-2-Butyltellanyl-1-chloroethenyl]cyclohex-1-ene
The TeII atom in the title molecule, C12H19ClTe, is coordinated in a V-shaped geometry by C atoms derived from the disparate organic substituents. A short intramolecular C—H⋯Cl contact occurs owing to the proximity of the ethene bond in the six-membered ring to the Cl atom. In the crystal, molecules assemble into layers parallel to the ac plane, with the closest interactions between them being of the Te⋯Te type [3.9993 (16) Å]
1-[(Z)-1-Bromo-2-(butyldichloro-λ4-tellanyl)ethenyl]cyclohex-1-ene
The TeIV atom in the title compound, [Te(C4H9)(C8H10Br)Cl2] or C12H19BrCl2Te, is in a distorted ψ-trigonal–bipyramidal geometry, with the lone pair of electrons projected to occupy a position in the equatorial plane, and with the Cl atoms being mutually trans [172.48 (4)°]. Close intramolecular [Te⋯Br = 3.3444 (18) Å] and intermolecular [Te⋯Cl = 3.675 (3) Å] interactions are observed. The latter lead to centrosymmetric dimers which assemble into layers in the bc plane. The primary connections between layers are of the type C—H⋯Cl
Copper catalyzed cross-coupling reactions of diaryl ditellurides with potassium aryltrifluoroborate salts
We present here results of the cross-coupling reaction of diaryl ditellurides with potassium aryltrifluoroborate salts using a catalytic amount of Cu(OAc)2 and bypiridine in DMSO/H2O under air atmosphere. This cross-coupling reaction is general and was performed with diaryl ditellurides and potassium aryltrifluoroborate salts bearing electron-withdrawing, electron-donating and neutral substituents, affording the corresponding unsymmetrical diaryl tellurides in good to excellent yields.Apresentamos aqui resultados das reações de acoplamento de diteluretos de diarila com sais de ariltrifluoroborato de potássio, usando quantidades catalíticas de Cu(OAc)2 e bipiridina, em uma mistura de DMSO/H2O, sob ar atmosférico. Estas reações de acoplamento são gerais e são realizadas com diteluretos de diarila e sais de ariltrifluoroborato de potássio contendo substituintes neutros, retiradores e doadores de elétrons, fornecendo os correspondentes teluretos de diarila não simétricos em rendimentos de bons a excelentes.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) (Grants 07/56659-0 and 07/59404-2
Recomendação de variedades de milho para o Sul do Brasil: rede de ensaios preliminares-Safra 2009/10.
bitstream/item/45104/1/circular-99.pd
Crystallographic, DFT and docking (cathepsin B) studies on an organotellurium(IV) compound
Some biologically active organotellurium compounds exhibit inhibitory potency against cathepsin B. In this study, an alkyl derivative, viz. [CH3(CH2)2C(I)=C(H)](nBu)TeI2, 1, has been structurally characterised by X-ray crystallography and shown to be coordinated within a C2I2 donor set. When the stereochemically active lone pair of electrons is taken into account, a distorted trigonal bipyramidal geometry results with the iodide atoms in axial positions. Both intra- and inter-molecular Te···I interactions are also noted. If all interactions are considered, the coordination geometry is based on a Ψ-pentagonal bipyramidal geometry. An unusual feature of the structure is the curving of the functionalised C5 chain. This feature has been explored by DFT methods and shown to arise as a result of close C–H···I interactions. A docking study (cathepsin B) was performed to understand the inhibition mechanism and to compare the new results with previous observations. Notably, 1 has the same pose exhibited by analogous biologically active compounds with aryl groups. Thus, the present study suggests that (alkyl)2TeX2 compounds should also be evaluated for biological activity
Ensaio regional de variedades de milho na Região Sul ? Safra 2009/10.
bitstream/item/79581/1/Comunicado-273.pd
Potassium trifluoro[(Z)-3-methoxyprop-1-enyl]borate
In the title salt, K+·C4H7BF3O−, the K atom is surrounded by six anions making close contacts through seven F [K⋯F = 2.779 (1)–3.048 (1) Å] and two O [K⋯O = 2.953 (2) and 3.127 (2) Å] atoms in a trivacant fac-vIC-9 icosahedral coordination geometry
Ensaio regional de variedades de milho na Região Sul - safra 2008/09.
A rede regional de ensaios de variedades de Milho tem por objetivo avaliar o comportamento de variedades comerciais de milho na região sul do Brasil. O resultado dos ensaios é publicado anualmente no Livro das Indicações Técnicas para o Cultivo de Milho e de Sorgo no RS. Esses resultados também servem para determinação do Valor de Cultivo e Uso (VCU), com vistas à extensão da indicação de uso de cultivares comerciais para o RS
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