Read by QxMD icon Read

inverse dynamics

S H Sun, C W Zhou, L Y Zhao, R Z Zhang, H Ouyang
Objective: To investigate whether texture analysis based on contrast-enhanced MRI can predict pathological complete response of locally advanced breast cancer undergoing neoadjuvant chemotherapy(NAC). Methods: Forty-seven patients with breast cancer undergone neoadjuvant chemotherapy from January 2015 to February 2016 were divided into pathological complete response (pCR) group or non-pathological complete response (non-pCR) group based on surgical pathology. Their parameters of texture analysis based on MRI before neoadjuvant chemotherapy and after 2 cycles of treatment were analyzed...
May 23, 2017: Zhonghua Zhong Liu za Zhi [Chinese Journal of Oncology]
Brandon L Peters, K Michael Salerno, Anupriya Agrawal, Dvora Perahia, Gary S Grest
The distinctive viscoelastic behavior of polymers results from a coupled interplay of motion on multiple length and time scales. Capturing the broad time and length scales of polymer motion remains a challenge. Using polyethylene (PE) as a model macromolecule, we construct coarse-grained (CG) models of PE with 3-6 methyl groups per CG bead and probe two critical aspects of the technique: pressure corrections required after iterative Boltzmann inversion (IBI) to generate CG potentials that match the pressure of reference fully-atomistic melt simulations and the transferability of CG potentials across temperatures...
May 23, 2017: Journal of Chemical Theory and Computation
Juan Xia, Jin Wang, Dongliang Chao, Zhen Chen, Zheng Liu, Jer-Lai Kuo, Jiaxu Yan, Ze Xiang Shen
Due to the easy intralayer gliding and weak interlayer van der Waals interaction in transition metal dichalcogenides (TMDs), ion (particularly Li(+)) intercalation has been used to modify and tune their atomic structures to obtain the desired optical, electronic and chemical properties for future optoelectronics and energy storage applications. A good understanding of the transformative structures during intercalation is critical. In this paper, we investigate the structural transformation dynamics of 2H-MoS2 using electrochemical Li(+) intercalation for 2H-MoS2...
May 23, 2017: Nanoscale
Noah E Horwitz, Brian T Phelan, Jordan N Nelson, Catherine M Mauck, Matthew D Krzyaniak, Michael R Wasielewski
Photoexcitation of electron donor-acceptor molecules frequently produces radical ion pairs with well-defined initial spin-polarized states that have attracted significant interest for spintronics. Transfer of this initial spin polarization to a stable radical is predicted to depend on the rates of the radical ion pair recombination reactions, but this prediction has not been tested experimentally. In this study, a stable radical/electron donor/chromophore/electron acceptor molecule, BDPA(•)-mPD-ANI-NDI, where BDPA(•) is α,γ-bisdiphenylene-β-phenylallyl, mPD is m-phenylenediamine, ANI is 4-aminonaphthalene-1,8-dicarboximide, and NDI is naphthalene-1,4:5,8-bis(dicarboximide), was synthesized...
May 22, 2017: Journal of Physical Chemistry. A
Marco E Rosti, Laura Kamps, Christoph Bruecker, Mohammad Omidyeganeh, Alfredo Pinelli
During the flight of birds, it is often possible to notice that some of the primaries and covert feathers on the upper side of the wing pop-up under critical flight conditions, such as the landing approach or when stalking their prey (see Fig. 1) . It is often conjectured that the feathers pop up plays an aerodynamic role by limiting the spread of flow separation . A combined experimental and numerical study was conducted to shed some light on the physical mechanism determining the feathers self actuation and their effective role in controlling the flow field in nominally stalled conditions...
2017: Meccanica
Alex Pui-Wai Lee, Chun-Na Jin, Yiting Fan, Randolph H L Wong, Malcolm J Underwood, Song Wan
OBJECTIVES: This study aimed to assess the hypothesis that mitral annular disjunction (MAD) is associated with abnormal annular dynamics due to decoupling of annular-ventricular function. BACKGROUND: MAD, defined as a separation between the atrial wall-mitral valve (MV) junction and left ventricular (LV) attachment, is a structural abnormality occurring in MV prolapse (MVP). Few data exist on the 3-dimensional (3D) geometry of MAD and its functional implication...
May 11, 2017: JACC. Cardiovascular Imaging
Rajesh Dutta, Kaushik Bagchi, Biman Bagchi
Kubo's fluctuation theory of line shape forms the backbone of our understanding of optical and vibrational line shapes, through such concepts as static heterogeneity and motional narrowing. However, the theory does not properly address the effects of quantum coherences on optical line shape, especially in extended systems where a large number of eigenstates are present. In this work, we study the line shape of an exciton in a one-dimensional lattice consisting of regularly placed and equally separated optical two level systems...
May 21, 2017: Journal of Chemical Physics
Chen Wang, Haowei Yang, Li Tian, Shiqiang Wang, Ning Gao, Wanlin Zhang, Peng Wang, Xianpeng Yin, Guangtao Li
A three-dimensional (3D) inverse opal with periodic and porous structures has shown great potential for applications not only in optics and optoelectronics, but also in functional membranes. In this work, the benzaldehyde group was initially introduced into a 3D nanoporous inverse opal, serving as a platform for fabricating functional membranes. By employing the dynamic covalent approach, a highly controllable gating system was facilely fabricated to achieve modulable and reversible transport features. It was found that the physical/chemical properties and pore size of the gating system could easily be regulated through post-modification with amines...
May 19, 2017: Nanoscale
Ce Wang, Pengfei Zhang, Xin Chen, Jinlong Yu, Hui Zhai
We show how the topological number of a static Hamiltonian can be measured from a dynamical quench process. We focus on a two-band Chern insulator in two dimension, for instance, the Haldane model, whose dynamical process can be described by a mapping from the [k_{x},k_{y},t] space to the Bloch sphere, characterized by the Hopf invariant. Such a mapping has been constructed experimentally by measurements in cold atom systems. We show that, taking any two constant vectors on the Bloch sphere, their inverse images of this mapping are two trajectories in the [k_{x},k_{y},t] space, and the linking number of these two trajectories exactly equals the Chern number of the static Hamiltonian...
May 5, 2017: Physical Review Letters
Anna F Delgado, Alberto F Delgado
BACKGROUND: DSC perfusion has been evaluated in the discrimination between low-grade and high-grade glioma but the diagnostic potential to discriminate beween glioma grades II and III remains unclear. PURPOSE: Our aim was to evaluate the diagnostic accuracy of relative maximal CBV from DSC perfusion MR imaging to discriminate glioma grades II and III. DATA SOURCES: A systematic literature search was performed in PubMed/MEDLINE, Embase, Web of Science, and ClinicalTrials...
May 18, 2017: AJNR. American Journal of Neuroradiology
Hilton Jeferson Alves Cardoso de Aguiar, Luísa Antônia Campos Barros, Danúbia Rodrigues Alves, Cléa Dos Santos Ferreira Mariano, Jacques Hubert Charles Delabie, Silvia das Graças Pompolo
Two valid ant species, Camponotus rufipes and Camponotus renggeri, have recently been the subject of a broad discussion with reference to taxa synonymization. Both species are quite common among the Neotropical myrmecofauna and share some unique traits, such as the shape of the scape and the pilosity patterns of the tibiae and scapes. A single morphological trait can help distinguish these species; however, only a combination of different approaches can enlighten our view of the complex phylogenetic relationships prevailing in the different populations of these two taxa...
2017: PloS One
Grzegorz Bauman, Orso Pusterla, Francesco Santini, Oliver Bieri
PURPOSE: To demonstrate the feasibility of oxygen-dependent relaxometry in human lung using an inversion recovery ultra-fast steady-state free precession (IR-ufSSFP) technique. METHODS: Electrocardiogram-triggered pulmonary relaxometry with IR-ufSSFP was performed in 7 healthy human subjects at 1.5 T. The data were acquired under both normoxic and hyperoxic conditions. In a single breath-hold of less than 9 seconds, 30 transient state IR-ufSSFP images were acquired, yielding longitudinal (T1) and transversal (T2) relaxometry parameter maps using voxel-wise nonlinear fitting...
May 18, 2017: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
Zhongshuai Zhang, Thomas Michaelis, Jens Frahm
BACKGROUND: Optimal control of minimally invasive interventions by hyperthermia requires dynamic temperature mapping at high temporal resolution. METHODS: Based on the temperature-dependent shift of the proton resonance frequency (PRF), this work developed a method for real-time MRI thermometry which relies on highly undersampled radial FLASH MRI sequences with iterative image reconstruction by regularized nonlinear inversion (NLINV). As a first step, the method was validated with use of a temperature phantom and ex vivo organs (swine kidney) subjected to heating by warm water or a pulsed laser source...
April 2017: Quantitative Imaging in Medicine and Surgery
Yan Xia, Hyun-Sook Jang, Zhiqiang Shen, Geoffrey D Bothun, Ying Li, Mu-Ping Nieh
The kinetics of clustering unilamellar vesicles induced by inverse Pluronics, poly(propylene oxide)m-poly(ethylene oxide)n-poly(propylene oxide)m, POm-EOn-POm, were investigated via experiments and molecular dynamic simulations. Two important factors for controlling the networking kinetics are the membrane defects presumably located at the interfacial region between two lipid domains induced by acyl chain mismatch, and the polymer hydrophobicity. As expected, the clustering rate increases significantly with increasing bilayer defects on the membrane where the insertion of PPO is likely to take place because of the reduced energy barrier for the insertion of PO...
May 16, 2017: Langmuir: the ACS Journal of Surfaces and Colloids
Mateusz Urbańczyk, Michał Nowakowski, Wiktor Koźmiński, Krzysztof Kazimierczuk
NMR relaxometry plays crucial role in studies of protein dynamics. The measurement of longitudinal and transverse relaxation rates of [Formula: see text]N is the main source of information on backbone motions. However, even the most basic approach exploiting a series of [Formula: see text]N HSQC spectra can require several hours of measurement time. Standard non-uniform sampling (NUS), i.e. random under-sampling of indirect time domain, typically cannot reduce this by more than 2-4[Formula: see text] due to relatively low "compressibility" of these spectra...
May 15, 2017: Journal of Biomolecular NMR
Katerina Shamalov, Shlomo N Levy, Miryam Horovitz-Fried, Cyrille J Cohen
p53 was reported to be an attractive immunotherapy target because it is mutated in approximately half of human cancers, resulting in its inactivation and often accumulation in tumor cells. Peptides derived from p53 are presented by class I MHC molecules and may act as tumor-associated epitopes which could be targeted by p53-specific T cells. Interestingly, it was recently shown that there is a lack of significant correlation between p53 expression levels in tumors and their recognition by p53-TCR transduced T cells...
2017: Oncoimmunology
Balázs Olasz, István Szabó, Gábor Czakó
Bimolecular nucleophilic substitution (SN2) and proton transfer are fundamental processes in chemistry and F(-) + CH3I is an important prototype of these reactions. Here we develop the first full-dimensional ab initio analytical potential energy surface (PES) for the F(-) + CH3I system using a permutationally invariant fit of high-level composite energies obtained with the combination of the explicitly-correlated CCSD(T)-F12b method, the aug-cc-pVTZ basis, core electron correlation effects, and a relativistic effective core potential for iodine...
April 1, 2017: Chemical Science
Rong-Wen Tain, Alessandro M Scotti, Weiguo Li, Xiaohong Joe Zhou, Kejia Cai
PURPOSE: To characterize the relaxation properties of reactive oxygen species (ROS) for the development of endogenous ROS contrast magnetic resonance imaging (MRI). MATERIALS AND METHODS: ROS-producing phantoms and animal models were imaged at 9.4T MRI to obtain T1 and T2 maps. Egg white samples treated with varied concentrations of hydrogen peroxide (H2 O2 ) were used to evaluate the effect of produced ROS in T1 and T2 for up to 4 hours. pH and temperature changes due to H2 O2 treatment in egg white were also monitored...
May 15, 2017: Journal of Magnetic Resonance Imaging: JMRI
Chenhui Hu, Xue Hua, Jun Ying, Paul M Thompson, Georges E Fakhri, Quanzheng Li
Pinpointing the sources of dementia is crucial to the effective treatment of neurodegenerative diseases. In this paper, we propose a diffusion model with impulsive sources over the brain connectivity network to model the progression of brain atrophy. To reliably estimate the atrophy sources, we impose sparse regularization on the source distribution and solve the inverse problem with an efficient gradient descent method. We localize the possible origins of Alzheimer's disease (AD) based on a large set of repeated magnetic resonance imaging (MRI) scans in Alzheimer's Disease Neuroimaging Initiative (ADNI) database...
October 2016: IEEE Journal of Selected Topics in Signal Processing
S De Angelis, O D Lamb, A Lamur, A J Hornby, F W von Aulock, G Chigna, Y Lavallée, A Rietbrock
The rapid discharge of gas and rock fragments during volcanic eruptions generates acoustic infrasound. Here we present results from the inversion of infrasound signals associated with small and moderate gas-and-ash explosions at Santiaguito volcano, Guatemala, to retrieve the time history of mass eruption rate at the vent. Acoustic waveform inversion is complemented by analyses of thermal infrared imagery to constrain the volume and rise dynamics of the eruption plume. Finally, we combine results from the two methods in order to assess the bulk density of the erupted mixture, constrain the timing of the transition from a momentum-driven jet to a buoyant plume, and to evaluate the relative volume fractions of ash and gas during the initial thrust phase...
June 28, 2016: Geophysical Research Letters
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"