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Source:Ultrasound in Medicine & Biology, Volume 44, Issue 4
http://ift.tt/2CDCZdB
Medicine by Alexandros G. Sfakianakis,Anapafseos 5 Agios Nikolaos 72100 Crete Greece,00302841026182,00306932607174,alsfakia@gmail.com,
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Publication date: Available online 22 February 2018
Source:Brain Stimulation
Author(s): Martin Keller, Wolfgang Taube, Benedikt Lauber
BackgroundMotor imagery and actual movements share overlapping activation of brain areas but little is known about task-specific activation of distinct motor pathways during mental simulation of movements. For real contractions, it was demonstrated that the slow(er) motor pathways are activated differently in ballistic compared to tonic contractions but it is unknown if this also holds true for imagined contractions.ObjectiveThe aim of the present study was to assess the activity of fast and slow(er) motor pathways during mentally simulated movements of ballistic and tonic contractions.MethodsH-reflexes were conditioned with transcranial magnetic stimulation at different interstimulus intervals to assess the excitability of fast and slow(er) motor pathways during a) the execution of tonic and ballistic contractions, b) motor imagery of these contraction types, and c) at rest.ResultsIn contrast to the fast motor pathways, the slow(er) pathways displayed a task-specific activation: for imagined ballistic as well as real ballistic contractions, the activation was reduced compared to rest whereas enhanced activation was found for imagined tonic and real tonic contractions.ConclusionsThis study provides evidence that the excitability of fast and slow(er) motor pathways during motor imagery resembles the activation pattern observed during real contractions. The findings indicate that motor imagery results in task- and pathway-specific subliminal activation of distinct subsets of neurons in the primary motor cortex.
http://ift.tt/2F28Auy
Publication date: 15 May 2018
Source:Behavioural Brain Research, Volume 344
Author(s): Alison E. Comrie, Daniel T. Gray, Anne C. Smith, Carol A. Barnes
Deficits in cognitive functions that rely on the integrity of the frontal and temporal lobes are characteristic of normative human aging. Due to similar aging phenotypes and homologous cortical organization between nonhuman primates and humans, several species of macaque monkeys are used as models to explore brain senescence. These macaque species are typically regarded as equivalent models of cognitive aging, yet no direct comparisons have been made to support this assumption. Here we used adult and aged rhesus and bonnet macaques (Macaca mulatta and Macaca radiata) to characterize the effect of age on acquisition and retention of information across delays in a battery of behavioral tasks that rely on prefrontal cortex and medial temporal lobe networks. The cognitive functions that were tested include visuospatial short-term memory, object recognition memory, and object-reward association memory. In general, bonnet macaques at all ages outperformed rhesus macaques on tasks thought to rely primarily on the prefrontal cortex, and were more resilient to age-related deficits in these behaviors. On the other hand, both species were comparably impaired by age on tasks thought to preferentially engage the medial temporal lobe. Together, these results suggest that rhesus and bonnet macaques are not equivalent models of cognitive aging and highlight the value of cross-species comparisons. These observations should enable improved design and interpretation of future experiments aimed at understanding changes in cognition across the lifespan.
http://ift.tt/2Fotm5y
Publication date: Available online 22 February 2018
Source:The Journal of Steroid Biochemistry and Molecular Biology
Author(s): Bhakti R. Pathak, Ananya A. Breed, Priyanka Deshmukh, Smita D. Mahale
Cysteine-rich secretory protein 3 (CRISP3) is one of the most upregulated genes in prostate cancer. Androgen receptor (AR) plays an important role not only in initial stages of prostate cancer development but also in the advanced stage of castration-resistant prostate cancer (CRPC). Role of AR in regulation of CRISP3 expression is not yet known. In order to understand the regulation of CRISP3 expression, various overlapping fragments of CRISP3 promoter were cloned in pGL3 luciferase reporter vector. All constructs were transiently and stably transfected in PC3 (CRISP3 negative) and LNCaP (CRISP3 positive) cell lines and promoter activity was measured by luciferase assay. Promoter activity of LNCaP stable clones was significantly higher than PC3 stable clones. Further in CRISP3 negative PC3 and RWPE-1 cells, CRISP3 promoter was shown to be silenced by histone deacetylation. Treatment of LNCaP cells with DHT resulted in increase in levels of CRISP3 transcript and protein. AR dependency of CRISP3 promoter was also evaluated in LNCaP stable clones by luciferase assay. To provide molecular evidence of epigenetic regulation of CRISP3 promoter and its response to DHT, ChIP PCR was performed in PC3 and LNCaP cells. Our results demonstrate that CRISP3 expression in prostate cancer cells is androgen dependent and in AR positive cells, CRISP3 promoter is epigenetically regulated by AR.
http://ift.tt/2BKzlSj
Publication date: 5 August 2018
Source:Applied Catalysis B: Environmental, Volume 229
Author(s): Raghavendra Shavi, Jeonghyun Ko, Ara Cho, Jeong Woo Han, Jeong Gil Seo
Conversion of CH4 and CO2 into value-added products has vital environmental and economic importance. Their direct conversion to acetic acid is challenging due to their high activation energy. Hence, kinetic and mechanistic information are crucial for the carbonylation of CH4 with CO2. Regarding this, single and dual component catalysts with different combinations of ZnO-, CeO2-, and MnO2- supported montmorillonite (MMT) were prepared and characterized by XPS, Raman, and XRD. Quick solid-state NMR, TGA, and FT-IR techniques were used and Langmuir-Hinshelwood model was considered to investigate mechanistic steps involved in the conversion of CH4 and CO2 to acetic acid. The obtained mechanistic and kinetic results were also theoretically proved by density functional theory (DFT) calculations. We found that ZnO and CeO2 dual active sites preferentially adsorb the CH4 and CO2, respectively that avoid surface adsorption competition. The rate of acetic acid formation was maximum when these sites exist at appropriate concentration (Ce: 0.44 wt%, Zn: 2.20 wt%). DFT calculations elucidated that the formation of acetic acid is strongly favored on ZnO catalyst with easier migration of the adsorbed CO2 from CeO2 to the ZnO side.
Publication date: 5 June 2018
Source:Journal of Molecular Structure, Volume 1161
Author(s): Xiu-Hui Ren, Peng Wang, Jun-Yan Cheng, Yu-Bin Dong
Three M(II)-coordination polymers (M Zn(II), Mn(II)) were synthesized based on a pyridine N-oxide bridging ligand 3,5-bis(4-carboxylphenyl)-pyridine N-oxide (L1). Compounds 1–3 all have novel complicated structures. Compound 1 (Zn(L1)2(H2O)2) and 2 (Zn2(L1)2(H2O)2) are two single crystals obtained in "one pot" and 1 features 1D double chains motif and 2 features 3D network structure. Compound 3 shows 3D network structure with triangular tunnels. The thermogravimetric analyses and photoluminescence properties were also used to investigate the title compounds.