Read by QxMD icon Read


Laurent M Sachs, Daniel R Buchholz
Thyroid hormone (TH) signaling comprises TH transport across cell membranes, metabolism by deiodinases, and molecular mechanisms of gene regulation. Proper TH signaling is essential for normal perinatal development, most notably for neurogenesis and fetal growth. Knowledge of perinatal TH endocrinology needs improvement to provide better treatments for premature infants and endocrine diseases during gestation and to counteract effects of endocrine disrupting chemicals. Studies in amphibians have provided major insights to understand in-vivo mechanisms of TH signaling...
January 21, 2017: Genesis: the Journal of Genetics and Development
C M Waugh, T Korff, A J Blazevich
Children perform cyclic motor tasks less efficiently than adults, however the mechanisms underlying such differences are not fully understood. One mechanism that may contribute these age-related differences is a differential contribution of muscles and tendons to a given muscle tendon unit (MTU) excursion. The aims of this study were to a) compare muscle and tendon excursion between children and adults performing vertical hopping, and b) determine if children and adults choose a hopping frequency that maximizes movement efficiency, based on the utilization of energy-saving mechanisms...
January 20, 2017: Journal of Experimental Biology
Tomoki Ozawa, Iacopo Carusotto
We discuss how one can realize a photonic device that combines synthetic dimensions and synthetic magnetic fields with spatially local interactions. Using an array of ring cavities, the angular coordinate around each cavity spans the synthetic dimension. The synthetic magnetic field arises as the intercavity photon hopping is associated with a change of angular momentum. Photon-photon interactions are local in the periodic angular coordinate around each cavity. Experimentally observable consequences of the synthetic magnetic field and of the local interactions are pointed out...
January 6, 2017: Physical Review Letters
Ana Šantić, Radha D Banhatti, Luka Pavić, Hüseyin Ertap, Mustafa Yüksek, Mevlüt Karabulut, Andrea Moguš-Milanković
The electrical and dielectric properties of three series of glasses, xHfO2-(40 - x)Fe2O3-60P2O5, 0 ≤ x ≤ 8 mol%, xCeO2-(40 - x)Fe2O3-60P2O5, 0 ≤ x ≤ 8 mol%, and xHfO2-(38 - x)Fe2O3-2B2O3-60P2O5 2 ≤ x ≤ 6 mol%, have been investigated by impedance spectroscopy over a wide frequency and temperature range. As expected, these glasses exhibit polaronic conductivity which strongly depends on the fraction of ferrous ions, Fe(2+)/Fetot. Following a detailed discussion on the DC conductivity, we use the MIGRATION concept to model their conductivity spectra...
January 20, 2017: Physical Chemistry Chemical Physics: PCCP
Chengzhen Sun, Bofeng Bai
Graphene provides a possibility where gas adsorption energy is comparable with molecular collision energy for physically adsorbed gases, resulting in the incompetence of the traditional hopping model to describe graphene-related surface diffusion phenomena. By calculating surface diffusion coefficients based on the Einstein equation, we exactly demonstrate that the gas diffusion on a graphene surface is a two-dimensional gas behavior mainly controlled by the collisions between adsorbed molecules. The surface diffusion on the graphene film just follows the bulk diffusion qualitatively, namely the diffusion coefficients decrease with increasing gas pressure...
January 20, 2017: Physical Chemistry Chemical Physics: PCCP
Yongfeng Zhang, Chao Jiang, Xianming Bai
This report presents an accelerated kinetic Monte Carlo (KMC) method to compute the diffusivity of hydrogen in hcp metals and alloys, considering both thermally activated hopping and quantum tunneling. The acceleration is achieved by replacing regular KMC jumps in trapping energy basins formed by neighboring tetrahedral interstitial sites, with analytical solutions for basin exiting time and probability. Parameterized by density functional theory (DFT) calculations, the accelerated KMC method is shown to be capable of efficiently calculating hydrogen diffusivity in α-Zr and Zircaloy, without altering the kinetics of long-range diffusion...
January 20, 2017: Scientific Reports
Cecilia Cisneros, Travis Thompson, Noel Baluyot, Adam C Smith, Enrico Tapavicza
To investigate the role of tachysterol in the photophysical/photochemical regulation of vitamin D photosynthesis, we studied its electronic absorption properties and excited state dynamics using time-dependent density functional theory (TDDFT), second-order approximate coupled cluster theory (CC2), and non-adiabatic surface hopping molecular dynamics in the gas phase. In excellent agreement with experiments, the simulated electronic spectrum shows a broad absorption band with a remarkably higher extinction coefficient than the other vitamin D photoisomers provitamin D, lumisterol, and previtamin D...
January 20, 2017: Physical Chemistry Chemical Physics: PCCP
Henrik Keränen, Laura Pérez-Benito, Myriam Ciordia, Francisca Delgado, Thomas B Steinbrecher, Daniel Oehlrich, Herman W T Van Vlijmen, Andrés A Trabanco, Gary Tresadern
A series of acylguanidine beta secretase 1 (BACE1) inhibitors with modified scaffold and P3 pocket substituent was synthesized and studied with Free Energy Perturbation (FEP) calculations. The resulting molecules showed potencies in enzymatic BACE1 inhibition assays up to 1 nM. The correlation between the predicted activity from the FEP calculations and the experimental activity was good for the P3 pocket substituents. The average mean unsigned error (MUE) between prediction and experiment was 0.68 ± 0.17 kcal/mol for the default 5 ns lambda window simulation time improving to 0...
January 19, 2017: Journal of Chemical Theory and Computation
Xiaojuan Pang, Xueyan Cui, Deping Hu, Chenwei Jiang, Di Zhao, Zhenggang Lan, Fu-Li Li
Photoisomerization dynamics of a light-driven molecular rotary motor, 9-(2-methyl-2,3-dihydro-1H-cyclopenta[a]naphthalen-1-ylidene)-9H-fluorene, is investigated with trajectory surface-hopping dynamics at the semi-empirical OM2/MRCI level. The rapid population decay of the S1 excited state for the M isomer is observed, with two different decay timescales (500 fs and 1.0 ps). By weighting the contributions of fast and slow decay trajectories, the averaged lifetime of the S1 excited state is about 710 fs. The calculated quantum yield of the M-to-P photoisomerization of this molecular rotary motor is about 59...
January 19, 2017: Journal of Physical Chemistry. A
Philipp Assmy, Mar Fernández-Méndez, Pedro Duarte, Amelie Meyer, Achim Randelhoff, Christopher J Mundy, Lasse M Olsen, Hanna M Kauko, Allison Bailey, Melissa Chierici, Lana Cohen, Anthony P Doulgeris, Jens K Ehn, Agneta Fransson, Sebastian Gerland, Haakon Hop, Stephen R Hudson, Nick Hughes, Polona Itkin, Geir Johnsen, Jennifer A King, Boris P Koch, Zoe Koenig, Slawomir Kwasniewski, Samuel R Laney, Marcel Nicolaus, Alexey K Pavlov, Christopher M Polashenski, Christine Provost, Anja Rösel, Marthe Sandbu, Gunnar Spreen, Lars H Smedsrud, Arild Sundfjord, Torbjørn Taskjelle, Agnieszka Tatarek, Jozef Wiktor, Penelope M Wagner, Anette Wold, Harald Steen, Mats A Granskog
The Arctic icescape is rapidly transforming from a thicker multiyear ice cover to a thinner and largely seasonal first-year ice cover with significant consequences for Arctic primary production. One critical challenge is to understand how productivity will change within the next decades. Recent studies have reported extensive phytoplankton blooms beneath ponded sea ice during summer, indicating that satellite-based Arctic annual primary production estimates may be significantly underestimated. Here we present a unique time-series of a phytoplankton spring bloom observed beneath snow-covered Arctic pack ice...
January 19, 2017: Scientific Reports
Rachel H Gilmore, Elizabeth M Y Lee, Mark C Weidman, Adam P Willard, William A Tisdale
Energetic disorder in quantum dot solids adversely impacts charge carrier transport in quantum dot solar cells and electronic devices. Here, we use ultrafast transient absorption spectroscopy to show that homogeneously broadened PbS quantum dot arrays (σhom(2):σinh(2)>19:1, σinh/kBT<0.4) can be realized if quantum dot batches are sufficiently monodisperse (δ ≲ 3.3%). Homogeneous linewidth is found to be an inverse function of quantum dot size, monotonically increasing from ~25 meV for the largest quantum dots (5...
January 19, 2017: Nano Letters
Zhongcheng Wei, Yongmei Sun, Yuefeng Ji
As an important coexistence technology, channel hopping can reduce the interference among Wireless Body Area Networks (WBANs). However, it simultaneously brings some issues, such as energy waste, long latency and communication interruptions, etc. In this paper, we propose an enhanced channel hopping mechanism that allows multiple WBANs coexisted in the same channel. In order to evaluate the coexistence performance, some critical metrics are designed to reflect the possibility of channel conflict. Furthermore, by taking the queuing and non-queuing behaviors into consideration, we present a set of analysis approaches to evaluate the coexistence capability...
January 14, 2017: Sensors
Gregory R Medders, Ethan C Alguire, Amber Jain, Joseph E Subotnik
We employ surface hopping trajectories to model the short-time dynamics of gas phase and partially solvated 4-(N,N-dimethylamino)benzonitrile (DMABN), a dual fluorescent molecule that is known to undergo a nonadiabatic transition through a conical intersection. To compare theory vs. time-resolved fluorescence measurements, we calculate the mixed quantum-classical density matrix and the ensemble averaged transition dipole moment. We introduce a diabatization scheme based on the oscillator strength to convert the TDDFT adiabatic states into diabatic states of La and Lb character...
January 18, 2017: Journal of Physical Chemistry. A
Peter Hunt, Matthew Segall, Noel O'Boyle, Roger Sayle
AIM: The assumption in scaffold hopping is that changing the scaffold does not change the binding mode and the same structure-activity relationships (SARs) are seen for substituents decorating each scaffold. Results/methodology: We present the use of matched series analysis, an extension of matched molecular pair analysis, to automate the analysis of a project's data and detect the presence or absence of comparable SAR between chemical series. CONCLUSION: The presence of SAR transfer can confirm the perceived binding mode overlay of different chemotypes or suggest new arrangements between scaffolds that may have gone unnoticed...
January 18, 2017: Future Medicinal Chemistry
Gabrielle Stetz, Gennady M Verkhivker
Allosteric interactions in the Hsp70 proteins are linked with their regulatory mechanisms and cellular functions. Despite significant progress in structural and functional characterization of the Hsp70 proteins fundamental questions concerning modularity of the allosteric interaction networks and hierarchy of signaling pathways in the Hsp70 chaperones remained largely unexplored and poorly understood. In this work, we proposed an integrated computational strategy that combined atomistic and coarse-grained simulations with coevolutionary analysis and network modeling of the residue interactions...
January 2017: PLoS Computational Biology
Kathia Lorena Jiménez-Monroy, Nicolas Renaud, Jeroen Drijkoningen, David Cortens, Christian Van Haesendonck, Wanda Julienne Guedens, Koen Schouteden, Jean V Manca, Laurens D A Siebbeles, Ferdinand C Grozema, Patrick Hermann Wagner
Determining the mechanism of charge transport through native DNA remains a challenge as different factors such as measuring conditions, molecule conformations and choice of technique can significantly affect the final results. In this contribution, we have used a new approach to measure current flowing through isolated double-stranded DNA molecules, using fullerene groups to anchor the DNA to a gold substrate. Measurements were performed at room temperature in an inert environment using a conductive AFM technique...
January 17, 2017: Journal of Physical Chemistry. A
Chi Chen, Ziheng Lu, Francesco Ciucci
Understanding Li diffusion in solid conductors is essential for the next generation Li batteries. Here we show that density-based clustering of the trajectories computed using molecular dynamics simulations helps elucidate the Li diffusion mechanism within the Li7La3Zr2O12 (LLZO) crystal lattice. This unsupervised learning method recognizes lattice sites, is able to give the site type, and can identify Li hopping events. Results show that, while the cubic LLZO has a much higher hopping rate compared to its tetragonal counterpart, most of the Li hops in the cubic LLZO do not contribute to the diffusivity due to the dominance of back-and-forth type jumps...
January 17, 2017: Scientific Reports
Marcin M Wysokiński, Jan Kaczmarczyk
We investigate the effect of the electron-hole (e-h) symmetry breaking on d-wave superconductivity induced by non-local effects of correlations in the generalized Hubbard model. The symmetry breaking is introduced in a two-fold manner: by the next-to-nearest neighbor hopping of electrons and by the charge-bond interaction-the off-diagonal term of the Coulomb potential. Both terms lead to a pronounced asymmetry of the superconducting order parameter. The next-to-nearest neighbor hopping enhances superconductivity for h-doping, while diminishes it for e-doping...
January 16, 2017: Journal of Physics. Condensed Matter: An Institute of Physics Journal
Ying Huang, Jeff Zhang, Zhengtian Yu, Hailong Zhang, Youzhen Wang, Andreas Lingel, Wei Qi, X Justin Gu, Kehao Zhao, Michael David Shultz, Long Wang, Xingnian Fu, Yongfeng Sun, Qiong Zhang, Xiangqing Jiang, Jiang-Wei Zhang, Chunye Zhang, Ling Li, Jue Zeng, Lijian Feng, Chao Zhang, Yueqin Liu, Man Zhang, Lijun Zhang, Mengxi Zhao, Zhenting Gao, Xianghui Liu, Douglas Fang, Haibing Guo, Yuan Mi, Tobias Gabriel, Michael P Dillon, Peter Atadja, Counde Oyang
Overexpression and somatic heterozygous mutations of EZH2, the catalytic subunit Polycomb repressive complex 2 (PRC2), are associated with several tumor types. EZH2 inhibitor, EPZ-6438 (Tazemetostat), demonstrated clinical efficacy in patients with acceptable safety profile as monotherapy. EED, another subunit of PRC2 complex, is essential for its histone methyltransferase activity through direct binding to trimethylated lysine 27 on histone 3 (H3K27Me3). Herein we disclose the discovery of a first-in-class potent, selective and orally bioavailable EED inhibitor EED226 (compound 43)...
January 16, 2017: Journal of Medicinal Chemistry
Yukiko Kawakami, Issei Ogasawara, Yasukazu Yonetani, Rikio Takao, Tatsuo Mae, Ken Nakata, Shuji Horibe
Since the loss of balance can result in falls or lower extremity injuries during sports or daily activities, quantitative evaluation of one's ability to maintain balance with changes in the direction of motion is crucial. The present study aimed to assess whether the trajectory length of the center of pressure (COP) and peak values of the ground reaction force (GRF) following a single-leg hop landing differ when hopping forward or laterally, and to ascertain disparities in balance characteristics due to differences in hop direction...
January 16, 2017: Kurume Medical Journal
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"