keyword
MENU ▼
Read by QxMD icon Read
search

system theory

keyword
https://www.readbyqxmd.com/read/28441477/local-electron-correlation-treatment-in-extended-multireference-calculations-effect-of-acceptor-donor-substituents-on-the-biradical-character-of-the-polycyclic-aromatic-hydrocarbon-heptazethrene
#1
Anita Das, Thomas Müller, Felix Plasser, David B Krisiloff, Emily A Carter, Hans Lischka
The implementation of a local correlation (LC) treatment of multireference (MR) configuration interaction approaches within the COLUMBUS program system is reported. The LC treatment is based on the weak pairs approximation of Sæbø and Pulay (Ann. Rev. Phys. Chem.44 (1993) 213) and a geometrical analysis of Walter et al. (Chem. Phys. Lett. 346 (2001) 177). The weak pairs interactions have been eliminated considering just the reference doubly occupied space leading to a straightforward program implementation and a conceptual simplicity in terms of well-defined localized orbitals...
April 25, 2017: Journal of Chemical Theory and Computation
https://www.readbyqxmd.com/read/28441344/collagenous-extracellular-matrix-biomaterials-for-tissue-engineering-lessons-from-the-common-sea-urchin-tissue
#2
REVIEW
Kheng Lim Goh, David F Holmes
Scaffolds for tissue engineering application may be made from a collagenous extracellular matrix (ECM) of connective tissues because the ECM can mimic the functions of the target tissue. The primary sources of collagenous ECM material are calf skin and bone. However, these sources are associated with the risk of having bovine spongiform encephalopathy or transmissible spongiform encephalopathy. Alternative sources for collagenous ECM materials may be derived from livestock, e.g., pigs, and from marine animals, e...
April 25, 2017: International Journal of Molecular Sciences
https://www.readbyqxmd.com/read/28440657/aromaticity-of-non-planar-fully-benzenoid-hydrocarbons
#3
Marija Antic, Boris Furtula, Slavko Radenković
The Clar aromatic sextet theory can provide the qualitative description on the dominant modes of cyclic π-electron conjugation in benzenoid molecules, and on the relative stability among a series of isomeric benzenoid systems. In a series of non-planar fully benzenoid hydrocarbons, the predictions of the Clar theory were tested by means of several different theoretical approaches: topological resonance energy (TRE), energy effect (ef), harmonic oscillator model of aromaticity (HOMA) index, six centre delocalization index (SCI) and nucleus independent chemical shifts (NICS)...
April 25, 2017: Journal of Physical Chemistry. A
https://www.readbyqxmd.com/read/28440644/direct-observation-of-the-ultrafast-evolution-of-open-shell-biradical-in-photochromic-radical-dimer
#4
Yoichi Kobayashi, Hajime Okajima, Hikaru Sotome, Takeshi Yanai, Katsuya Mutoh, Yusuke Yoneda, Yasuteru Shigeta, Akira Sakamoto, Hiroshi Miyasaka, Jiro Abe
Delocalized biradicals have been extensively studied because of fundamental interests to singlet biradicals and several potential applications such as to two-photon absorption materials. However, many of the biradical studies only focus on the static properties of the rigid molecular structures. It is expected that the biradical properties of the delocalized biradicals are sensitive to the subtle changes of the molecular structures and their local environments. Therefore, the studies of the dynamic properties of the system will give further insight into stable radical chemistry...
April 25, 2017: Journal of the American Chemical Society
https://www.readbyqxmd.com/read/28440549/feel-american-watch-american-eat-american-remote-acculturation-tv-and-nutrition-among-adolescent-mother-dyads-in-jamaica
#5
Gail M Ferguson, Henna Muzaffar, Maria I Iturbide, Hui Chu, Julie Meeks Gardner
Globalization prompts remote acculturation toward U.S. culture in Jamaica; this study used a bioecological systems approach to examine its proximal impact on nutrition through U.S. cable TV consumption, and maternal influences in the home. Overall, 330 randomly selected adolescent-mother dyads from schools in Kingston, Jamaica (Madolescent_age  = 13.8 years, SDadolescent_age  = 1.8) completed questionnaires reporting American identity and behavioral preferences, daily time spent watching U.S.-produced TV programs, and frequency of eating unhealthy foods...
April 25, 2017: Child Development
https://www.readbyqxmd.com/read/28440387/thermal-bending-coupled-with-volume-change-in-liquid-crystal-gels
#6
Haruka Doi, Kenji Urayama
We investigate the thermal bending behavior of liquid crystal gels with hybrid alignment (H-LCGs) accompanied by volume change in isotropic and nematic solvents. The curvature (r(-1)) of H-LCGs in each solvent markedly depends on the temperature (T) in the nematic state including the reversal of the bending direction, as in the case of the corresponding elastomers in the dry state (H-LCE). The thermal bending of three systems-H-LCGs in isotropic and nematic solvents and H-LCE-differs significantly in several aspects including the T range where r(-1) depends on T and the total variation of r(-1)...
April 25, 2017: Soft Matter
https://www.readbyqxmd.com/read/28440289/toward-surface-orbitronics-giant-orbital-magnetism-from-the-orbital-rashba-effect-at-the-surface-of-sp-metals
#7
Dongwook Go, Jan-Philipp Hanke, Patrick M Buhl, Frank Freimuth, Gustav Bihlmayer, Hyun-Woo Lee, Yuriy Mokrousov, Stefan Blügel
As the inversion symmetry is broken at a surface, spin-orbit interaction gives rise to spin-dependent energy shifts - a phenomenon which is known as the spin Rashba effect. Recently, it has been recognized that an orbital counterpart of the spin Rashba effect - the orbital Rashba effect - can be realized at surfaces even without spin-orbit coupling. Here, we propose a mechanism for the orbital Rashba effect based on sp orbital hybridization, which ultimately leads to the electric polarization of surface states...
April 25, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28440220/rapid-evolution-of-the-human-mutation-spectrum
#8
Kelley Harris, Jonathan K Pritchard
DNA is a remarkably precise medium for copying and storing biological information. This high fidelity results from the action of hundreds of genes involved in replication, proofreading, and damage repair. Evolutionary theory suggests that in such a system, selection has limited ability to remove genetic variants that change mutation rates by small amounts or in specific sequence contexts. Consistent with this, using SNV variation as a proxy for mutational input, we report here that mutational spectra differ substantially among species, human continental groups and even some closely-related populations...
April 25, 2017: ELife
https://www.readbyqxmd.com/read/28439779/searching-for-an-internal-representation-of-stimulus-kinematics-in-the-response-of-ventral-paraflocculus-purkinje-cells
#9
Pablo M Blazquez, GyuTae Kim, Tatyana A Yakusheva
Motor control theories propose that the central nervous system builds internal representations of the motion of both our body and external objects. These representations, called forward models, are essential for accurate motor control. For instance, to produce a precise reaching movement to catch a flying ball, the central nervous system must build predictions of the current and future states of both the arm and the ball. Accumulating evidence suggests that the cerebellar cortex contains a forward model of an individual's body movement...
April 24, 2017: Cerebellum
https://www.readbyqxmd.com/read/28439561/first-detection-of-equatorial-dark-dust-lane-in-a-protostellar-disk-at-submillimeter-wavelength
#10
Chin-Fei Lee, Zhi-Yun Li, Paul T P Ho, Naomi Hirano, Qizhou Zhang, Hsien Shang
In the earliest (so-called "Class 0") phase of Sun-like (low-mass) star formation, circumstellar disks are expected to form, feeding the protostars. However, these disks are difficult to resolve spatially because of their small sizes. Moreover, there are theoretical difficulties in producing these disks in the earliest phase because of the retarding effects of magnetic fields on the rotating, collapsing material (so-called "magnetic braking"). With the Atacama Large Millimeter/submillimeter Array (ALMA), it becomes possible to uncover these disks and study them in detail...
April 2017: Science Advances
https://www.readbyqxmd.com/read/28437869/risk-modeling-of-interdependent-complex-systems-of-systems-theory-and-practice
#11
Yacov Y Haimes
The emergence of the complexity characterizing our systems of systems (SoS) requires a reevaluation of the way we model, assess, manage, communicate, and analyze the risk thereto. Current models for risk analysis of emergent complex SoS are insufficient because too often they rely on the same risk functions and models used for single systems. These models commonly fail to incorporate the complexity derived from the networks of interdependencies and interconnectedness (I-I) characterizing SoS. There is a need to reevaluate currently practiced risk analysis to respond to this reality by examining, and thus comprehending, what makes emergent SoS complex...
April 24, 2017: Risk Analysis: An Official Publication of the Society for Risk Analysis
https://www.readbyqxmd.com/read/28437698/coupled-elasticity-in-soft-solid-foams
#12
F Gorlier, Y Khidas, O Pitois
Elasticity of soft materials can be greatly influenced by the presence of air bubbles. Such a capillary effect is expected for a wide range of materials, from polymer gels to concentrated emulsions and colloidal suspensions. Whereas experimental results and theory exist for describing the elasto-capillary behavior of bubbly materials (i.e. with moderate gas volume fractions), foamy systems still require a dedicated study in order to increase our understanding of elasticity in aerated materials over the full range of gas volume fractions...
April 12, 2017: Journal of Colloid and Interface Science
https://www.readbyqxmd.com/read/28436661/performance-of-van-der-waals-corrected-functionals-for-guest-adsorption-in-the-m2-dobdc-metal-organic-frameworks
#13
Bess Vlaisavljevich, Johanna M Huck, Zeric Hulvey, Kyuho Lee, Jarad A Mason, Jeffrey B Neaton, Jeffrey R Long, Craig M Brown, Dario Alfè, Angelos Michaelides, Berend Smit
Small molecule binding in metal-organic frameworks (MOFs) can be accurately studied both experimentally and computationally, provided the proper tools are employed. Herein, we compare and contrast properties associated with guest binding by means of density functional theory (DFT) calculations using nine different functionals for the M2(dobdc) (dobdc4- = 2,5-dioxido,1,4-benzenedicarboxylate) series where M = Mg, Mn, Fe, Co, Ni, Cu, and Zn. Additionally, we perform Quantum Monte Carlo (QMC) calculations for one system to determine if this method can be used to assess the performance of DFT...
April 24, 2017: Journal of Physical Chemistry. A
https://www.readbyqxmd.com/read/28436548/an-open-source-framework-for-analyzing-n-electron-dynamics-i-multideterminantal-wave-functions
#14
Vincent Pohl, Gunter Hermann, Jean Christophe Tremblay
The aim of the present contribution is to provide a framework for analyzing and visualizing the correlated many-electron dynamics of molecular systems, where an explicitly time-dependent electronic wave packet is represented as a linear combination of N-electron wave functions. The central quantity of interest is the electronic flux density, which contains all information about the transient electronic density, the associated phase, and their temporal evolution. It is computed from the associated one-electron operator by reducing the multideterminantal, many-electron wave packet using the Slater-Condon rules...
April 24, 2017: Journal of Computational Chemistry
https://www.readbyqxmd.com/read/28436535/the-role-of-the-long-range-exchange-corrections-in-the-description-of-electron-delocalization-in-aromatic-species
#15
Dariusz W Szczepanik, Miquel Solà, Marcin Andrzejak, Barbara Pawełek, Justyna Dominikowska, Mercedes Kukułka, Karol Dyduch, Tadeusz M Krygowski, Halina Szatylowicz
In this article, we address the role of the long-range exchange corrections in description of the cyclic delocalization of electrons in aromatic systems at the density functional theory level. A test set of diversified monocyclic and polycyclic aromatics is used in benchmark calculations involving various exchange-correlation functionals. A special emphasis is given to the problem of local aromaticity in acenes, which has been a subject of long-standing debate in the literature. The presented results indicate that the noncorrected exchange-correlation functionals significantly overestimate cyclic delocalization of electrons in heteroaromatics and aromatic systems with fused rings, which in the case of acenes leads to conflicting local aromaticity predictions from different criteria...
April 24, 2017: Journal of Computational Chemistry
https://www.readbyqxmd.com/read/28436523/mechanistic-insights-into-the-selective-cyclization-of-indolines-with-alkynes-and-alkenes-to-produce-six-and-seven-membered-1-7-fused-indolines-via-rh-iii-catalysis-a-theoretical-study
#16
Lingli Han, Xinyu Zhang, Xingdong Wang, Fengyue Zhao, Shaojing Liu, Tao Liu
The coupling reaction mechanisms of the Rh(iii)-catalyzed redox-neutral C7-selective aryl C-H functionalization of indolines with alkynes and alkenes have been theoretically investigated with the aid of the density functional theory (DFT) calculations. Our calculation results indicate that the active catalyst in this system is the cationic species [Cp*Rh(OAc)](+) (2cat) instead of the neutral species Cp*Rh(OAc)2 (1cat). The origin of forming different products associated with using different coupling partners was also rationalized in detail...
April 24, 2017: Organic & Biomolecular Chemistry
https://www.readbyqxmd.com/read/28436265/recruiting-african-american-children-for-research-an-ecological-systems-theory-approach
#17
Diane Graves, Jane P Sheldon
With health disparities still pervasive and persistent in the United States, medical researchers and social scientists continue to develop recruitment strategies to increase the inclusion of racial/ethnic minority groups in research and interventions. Effective methods for recruiting samples of African American participants for pediatric research may be best understood when situated within an overarching conceptual model-one that serves to organize and explain effective recruitment strategies. A theoretical framework well suited for this purpose is Bronfenbrenner's ecological systems theory, which views individuals as influencing and being influenced by (both directly and indirectly) a series of interconnected social systems...
April 1, 2017: Western Journal of Nursing Research
https://www.readbyqxmd.com/read/28435554/influence-of-soluble-fillers-in-improving-porosity-of-handmade-antibiotic-impregnated-polymethyl-methacrylate-pmma-beads-an-in-vitro-study
#18
H N Rasyid, S Soegijoko
There have been many investigations on non-biodegradable materials acting as an antibiotic carrier for local drug delivery systems based on polymethyl methacrylate (PMMA) beads. However, the material is non-degradable and non-porous so that less than 5% of the encapsulated drug is released. In order to obtain better release of the antibiotics, greater porosity of the beads would be required. Adding fillers could increase the bead's porosity, thus improving the antibiotic release from the beads. The purpose of the study is to optimize release kinetics of gentamicin from handmade beads by adding fillers such as glycine and sodium chloride in different concentrations...
July 2016: Malaysian Orthopaedic Journal
https://www.readbyqxmd.com/read/28434560/accelerated-fatigue-testing-of-dentin-composite-bond-with-continuously-increasing-load
#19
Kai Li, Jiawen Guo, Yuping Li, Young Cheul Heo, Jihua Chen, Haitao Xin, Alex Fok
OBJECTIVES: The aim of this study was to evaluate an accelerated fatigue test method that used a continuously increasing load for testing the dentin-composite bond strength. METHODS: Dentin-composite disks (ϕ5mm×2mm) made from bovine incisor roots were subjected to cyclic diametral compression with a continuously increasingly load amplitude. Two different load profiles, linear and nonlinear with respect to the number of cycles, were considered. The data were then analyzed by using a probabilistic failure model based on the Weakest-Link Theory and the classical stress-life function, before being transformed to simulate clinical data of direct restorations...
April 20, 2017: Dental Materials: Official Publication of the Academy of Dental Materials
https://www.readbyqxmd.com/read/28433162/tocopheryl-acetate-release-from-microcapsules-of-waxy-maize-starch
#20
Naksit Panyoyai, Robert A Shanks, Stefan Kasapis
Diffusion coefficients are utilised to provide a realistic approach in the quantification of mass transport phenomena, which are important for the delivery of bioactivity from high-solid biopolymer systems. Following this mechanistic consideration, we employ spray drying to produce microcapsules of waxy maize starch that suspend homogeneously tocopheryl acetate. An array of physicochemical techniques including dynamic oscillation in-shear or compression mode, microDSC, WAXD, FTIR, scanning electron or optical microscopy, and UV-vis assays were utilised to relate structural properties of the macromolecular network to diffusivity of the bioactive compound...
July 1, 2017: Carbohydrate Polymers
keyword
keyword
80957
1
2
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"