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Activation theory

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https://www.readbyqxmd.com/read/28734206/theoretical-investigation-of-the-conformational-space-of-baicalin
#1
Juan J Martínez Medina, Evelina G Ferrer, Patricia A M Williams, Nora B Okulik
Flavonoids are a large group of polyphenolic compounds ubiquitously present in plants. They are important components of human diet. They are recognized as potential drug candidates to be used in the treatment and prevention of a lot of pathological disorders, due to their protective effects. Baicalin (7-glucuronic acid 5, 6-dihydroxyflavone) is one of the main single active constituents isolated from the dried roots of Scutellaria baicalensis Georgi. The great interest on this flavonoid is due to its various pharmacological properties, such as antioxidant, antimicrobial, anti-inflammatory, anticancer and so on, and its high accumulation in the roots of S...
July 11, 2017: Journal of Molecular Graphics & Modelling
https://www.readbyqxmd.com/read/28732236/neighborhood-ses-is-particularly-important-to-the-cardiovascular-health-of-low-ses-individuals
#2
Jennifer Morozink Boylan, Stephanie A Robert
RATIONALE: Health disparities defined by neighborhood socioeconomic status (SES) are well established; it is less well understood whether neighborhood SES is differentially associated with health depending on one's own SES. OBJECTIVE: The double jeopardy hypothesis, collective resources model, fundamental cause theory, and relative deprivation hypothesis support differential patterns of association between neighborhood and individual SES with health. The first three models suggest that higher neighborhood SES predicts health more strongly among lower, as compared to higher, SES individuals...
July 8, 2017: Social Science & Medicine
https://www.readbyqxmd.com/read/28732136/an-approach-to-estimate-the-activation-energies-of-fragmentation-occurring-in-quadrupole-collision-cell-of-the-mass-spectrometer
#3
Ákos Kuki, Lajos Nagy, Miklós Zsuga, Sándor Kéki
The classical semi-quantitative Rice-Ramsperger-Kassel (RRK) theory was used for the calculation of the internal energy dependent reaction rate coefficient of the collision-induced dissociation (CID) reaction in tandem mass spectrometry (MS/MS). The survival yield (SY) was determined by the reaction rate equation for the unimolecular dissociation of the precursor ion. The parameters of the rate equation and the RRK model were approximated based on the instrumental conditions. We used the RRK equation for the description of the basic behavior of the fragmentation reactions and for the estimation of the internal energy of the precursor ion...
July 21, 2017: Journal of Mass Spectrometry: JMS
https://www.readbyqxmd.com/read/28731720/analytic-energy-gradients-for-variational-two-electron-reduced-density-matrix-driven-complete-active-space-self-consistent-field-theory
#4
Elvis Maradzike, Gergely Gidofalvi, Justin M Turney, Henry F Schaefer, A Eugene DePrince
Analytic energy gradients are presented for a variational two-electron reduced-density matrix (2-RDM)-driven complete active space self-consistent field (CASSCF) method. The active-space 2-RDM is determined using a semidefinite programing (SDP) algorithm built upon an augmented Lagrangian formalism. Expressions for analytic gradients are simplified by the fact that the Lagrangian is stationary with respect to variations in both the primal and dual solutions to the SDP problem. Orbital response contributions to the gradient are identical to those that arise in conventional CASSCF methods in which the electronic structure of the active space is described by a full configuration interaction (CI) wave function...
July 21, 2017: Journal of Chemical Theory and Computation
https://www.readbyqxmd.com/read/28731706/automated-construction-of-molecular-active-spaces-from-atomic-valence-orbitals
#5
Elvira R Sayfutyarova, Qiming Sun, Garnet Kin-Lic Chan, Gerald Knizia
We introduce the atomic valence active space (AVAS), a simple and well-defined automated technique for constructing active orbital spaces for use in multi-configuration and multi-reference (MR) electronic structure calculations. Concretely, the technique constructs active molecular orbitals capable of describing all relevant electronic configurations emerging from a targeted set of atomic valence orbitals (e.g., the metal d orbitals in a redcoordination complex). This is achieved via a linear transformation of the occupied and unoccupied orbital spaces from an easily obtainable single-reference wavefunction (such as from a Hartree-Fock or Kohn-Sham calculations) based on projectors to targeted atomic valence orbitals...
July 21, 2017: Journal of Chemical Theory and Computation
https://www.readbyqxmd.com/read/28731385/kids-sip-smarter-a-feasibility-study-to-reduce-sugar-sweetened-beverage-consumption-among-middle-school-youth-in-central-appalachia
#6
Hannah Lane, Kathleen J Porter, Erin Hecht, Priscilla Harris, Vivica Kraak, Jamie Zoellner
PURPOSE: To test the feasibility of Kids SIP smartER, a school-based intervention to reduce consumption of sugar-sweetened beverages (SSBs). DESIGN: Matched-contact randomized crossover study with mixed-methods analysis. SETTING: One middle school in rural, Appalachian Virginia. PARTICIPANTS: Seventy-four sixth and seventh graders (5 classrooms) received Kids SIP smartER in random order over 2 intervention periods. Feasibility outcomes were assessed among 2 teachers...
January 1, 2017: American Journal of Health Promotion: AJHP
https://www.readbyqxmd.com/read/28730755/the-unusual-role-of-the-aromatic-solvent-in-single-site-al-i-chemistry-insights-from-theory
#7
Shailja Jain, Kumar Vanka
The single site activation of strong σ bonds (such as that of H-H, P-H and N-H) remains a significant challenge in main group chemistry, with only a few cases reported to date. In this regard, recent exciting experiments done with Al(I) complexes hold significance, because they, too, have been seen to activate a variety of strong σ bonds. Such chemistry is generally seen to occur in aromatic solvents. The current computational studies with density functional theory (DFT) reveal the interesting reason for this: it is seen that an explicit aromatic solvent molecule acts as a catalyst by converting the Al(I) complex to Al(III) during the process...
July 21, 2017: Chemistry: a European Journal
https://www.readbyqxmd.com/read/28730703/synthesis-structure-and-properties-of-near-infrared-b-phenanthrene-fused-bf2-aza-dipyrromethenes
#8
Jiuen Cui, Wanle Sheng, Qinghua Wu, Changjiang Yu, Erhong Hao, Petia Bobadova-Parvanova, Marie Storer, Abdullah M Asiri, Hadi M Marwani, Lijuan Jiao
A new class of phenanthrene-fused BF2 aza-dipyrromethene (aza-BODIPY) dyes has been synthesized through tandem Suzuki reaction and oxidative ring-fusion reaction or the Palladium catalyzed intramolecular C-H activation reaction. These phenanthrene-fused aza-BODIPY dyes are highly photostable and display markedly red shifted absorption (up to 771 nm) and emission bands (around 800 nm) in the Near-Infrared (NIR) region. Density functional theory (DFT) calculation and cyclic voltammetry studies indicate that upon annulations, the more-pronounced stabilization of the LUMO is the origin of bathochromic shift of the absorption and high photostability...
July 20, 2017: Chemistry, An Asian Journal
https://www.readbyqxmd.com/read/28730559/fathers-know-best-inner-city-african-american-fathers-perceptions-regarding-their-involvement-in-the-pediatric-medical-home
#9
Orville Newton-Ray Bignall, Whitney J Raglin Bignall, Lisa M Vaughn, Ndidi I Unaka
OBJECTIVE: Despite nearly three in four African American (AA) children being born to unwed mothers, AA fathers maintain relatively high levels of parenting engagement, whether or not they live with their children. While father involvement correlates with decreased adverse child health outcomes, the nature of AA father involvement in child health-including engagement in the pediatric medical home-remains largely unexplored. Our study aimed to assess perceptions of pediatric medical home participation among a cohort of urban, AA fathers...
July 20, 2017: Journal of Racial and Ethnic Health Disparities
https://www.readbyqxmd.com/read/28729927/fatigue-and-cognition-pupillary-responses-to-problem-solving-in-early-multiple-sclerosis-patients
#10
Sigrid A de Rodez Benavent, Gro O Nygaard, Hanne F Harbo, Siren Tønnesen, Piotr Sowa, Nils I Landrø, Marte Wendel-Haga, Lars Etholm, Kristian B Nilsen, Liv Drolsum, Emilia Kerty, Elisabeth G Celius, Bruno Laeng
INTRODUCTION: In early multiple sclerosis (MS) patients, cognitive changes and fatigue are frequent and troublesome symptoms, probably related to both structural and functional brain changes. Whether there is a common cause of these symptoms in MS is unknown. In theory, an altered regulation of central neuropeptides can lead to changes in regulation of autonomic function, cognitive difficulties, and fatigue. Direct measurements of central neuropeptides are difficult to perform, but measurements of the eye pupil can be used as a reliable proxy of function...
July 2017: Brain and Behavior
https://www.readbyqxmd.com/read/28729843/is-a-transdisciplinary-theory-of-engagement-in-organized-settings-possible-a-concept-analysis-of-the-literature-on-employee-engagement-consumer-engagement-and-patient-engagement
#11
REVIEW
Guendalina Graffigna
Organizations are experiencing increased competition, disruptive innovation, and continuous changes in their social and economic context. Furthermore, the decrease of resources (economic and human) in such a demanding context make it imperative for organizations to find new models and strategies to make their service delivery more sustainable at the economic, environmental and psychological levels. In such a complex scenario the concept of engagement of the individuals involved in organized settings (either as service providers or as final receivers) is a promising lever for innovation...
2017: Frontiers in Psychology
https://www.readbyqxmd.com/read/28728857/-rosacea-new-data-for-better-care
#12
B Cribier
In the last 10 years, numerous studies have been published that throw new light on rosacea, in all areas of the disease. This overview summarises all the key developments, based on the indexed bibliography appearing in Medline between 2007 and 2017. Recent epidemiological data show that the prevalence of the disease is doubtless greater than estimated hitherto (more than 10% of adults in some countries) and that we should not overlook rosacea in subjects with skin phototypes V or VI, a condition that exists on all continents...
July 17, 2017: Annales de Dermatologie et de Vénéréologie
https://www.readbyqxmd.com/read/28727547/designing-and-implementation-of-stable-sinusoidal-rough-neural-identifier
#13
Ghasem Ahmadi, Mohammad Teshnehlab
A rough neuron is defined as a pair of conventional neurons that are called the upper and lower bound neurons. In this paper, the sinusoidal rough-neural networks (SR-NNs) are used to identify the discrete dynamic nonlinear systems (DDNSs) with or without noise in series-parallel configuration. In the identification of periodic nonlinear systems, sinusoidal activation functions provide more efficient neural networks than the sigmoidal activation functions. Based on the Lyapunov stability theory, an online learning algorithm is developed to train the SR-NNs...
August 2017: IEEE Transactions on Neural Networks and Learning Systems
https://www.readbyqxmd.com/read/28727144/density-mediated-indirect-effects-from-active-predators-and-narrow-habitat-domain-prey
#14
S A Rinehart, S C Schroeter, J D Long
The hunting mode-habitat domain range framework suggests that the mechanism driving trophic cascades [i.e. trait-mediated indirect interactions (TMIIs) versus density-mediated indirect interactions (DMIIs)] should depend upon the functional traits of predators and prey. For example, trophic cascades containing active, broad habitat domain range (BHDR) predators interacting with narrow habitat domain range (NHDR) prey are predicted to arise primarily via TMIIs, because these prey should reduce their conspicuous activity in the presence of these predators...
July 20, 2017: Ecology
https://www.readbyqxmd.com/read/28726670/solid-state-nanopore-based-biomimetic-voltage-gated-ion-channels
#15
Matthew Pevarnik, Weibin Cui, Sukru Yemenicioglu, Justin Rofeh, Luke Theogarajan
Voltage gating is essential to the computational ability of neurons. We show this effect can be mimicked in a solid-state nanopore by functionalizing the pore interior with a redox active molecule. We study the integration of an active biological molecule, a quinone, into a solid state nanopore and its subsequent induced voltage gating. We show that the voltage gating effect mimics biological gating systems in its classic sigmoidal voltage response, unlike previous synthetic voltage gating systems. Initially the quinone undergoes a reduction due to radicals in the bulk solution and is converted to the hydroquinone state...
July 20, 2017: Bioinspiration & Biomimetics
https://www.readbyqxmd.com/read/28726476/spouses-daily-feelings-of-appreciation-and-self-reported-well-being
#16
Joan K Monin, Michael J Poulin, Stephanie L Brown, Kenneth M Langa
OBJECTIVE: Research shows that active support provision is associated with greater well-being for spouses of individuals with chronic conditions. However, not all instances of support may be equally beneficial for spouses' well-being. The theory of communal responsiveness suggests that because spouses' well-being is interdependent, spouses benefit most from providing support when they believe their support increases their partner's happiness and is appreciated. Two studies tested this hypothesis...
July 20, 2017: Health Psychology: Official Journal of the Division of Health Psychology, American Psychological Association
https://www.readbyqxmd.com/read/28726388/detection-of-pesticide-residues-in-food-using-surface-enhanced-raman-spectroscopy-a-review
#17
Menglei Xu, Yu Gao, Xiao Xia Han, Bing Zhao
Pesticides directly pollute the environment and contaminate foods ultimately being absorbed by the human body. Their residues contain highly toxic substances that have been found to cause serious problems to human health even at very low concentrations. The gold standard method, gas/liquid chromatography combined with mass spectroscopy, has been widely used for the detection of pesticide residues. However, these methods have some drawbacks such as complicated pre-treatment and cleanup steps. Recent technological advancements of surface-enhanced Raman spectroscopy (SERS) has promoted the creation of alternative detection techniques...
July 20, 2017: Journal of Agricultural and Food Chemistry
https://www.readbyqxmd.com/read/28726372/influence-of-relativistic-effects-on-assembled-structures-of-v-shaped-bispyridine-molecules-on-m-111-surfaces-where-m-cu-ag-au
#18
Xue Zhang, Na Li, Hao Wang, Chenyang Yuan, Gaochen Gu, Yajie Zhang, Damian Nieckarz, Paweł Szabelski, Shimin Hou, Boon K Teo, Yongfeng Wang
The self-assembly behavior of a V-shaped bispyridine, 1,3-bi(4-pyridyl)benzene (BPyB), was studied by scanning tunneling microscopy on the (111) surfaces of Cu, Ag, and Au. BPyB molecules coordinately bonded with active Cu adatoms on Cu(111) in the form of complete polygonal rings at low coverages. On Ag(111), BPyB molecules aggregated into two-dimensional islands by relatively weak intermolecular hydrogen bonds. The coexistence of hydrogen bonds and coordination interaction was observed on the BPyB-covered Au(111) substrate...
July 21, 2017: ACS Nano
https://www.readbyqxmd.com/read/28726316/deprotonation-states-of-the-two-active-site-water-molecules-regulate-the-binding-of-protein-phosphatase-5-with-its-substrate-a-molecular-dynamics-study
#19
Lingyun Wang, Feng Yan
Protein phosphatase 5 (PP5), mainly localized in human brain, can dephosphorylate tau protein whose high level of phosphorylation is related to Alzheimer's disease. Similar to other protein phosphatases, PP5 has a conserved motif in the catalytic domain that contains two binding sites for manganese (Mn(2+) ) ions. Structural data indicate that two active site water molecules, one bridging the two Mn(2+) ions and the other terminally coordinated with one of the Mn(2+) ions (Mn1), are involved in catalysis. Recently, a density functional theory study revealed that the two water molecules can be both deprotonated to keep a neutral active site for catalysis...
July 20, 2017: Protein Science: a Publication of the Protein Society
https://www.readbyqxmd.com/read/28726213/how-mechanisms-explain-interfield-cooperation-biological-chemical-study-of-plant-growth-hormones-in-utrecht-and-pasadena-1930-1938
#20
Caterina Schürch
This article examines to what extent a particular case of cross-disciplinary research in the 1930s was structured by mechanistic reasoning. For this purpose, it identifies the interfield theories that allowed biologists and chemists to use each other's techniques and findings, and that provided the basis for the experiments performed to identify plant growth hormones and to learn more about their role in the mechanism of plant growth. In 1930, chemists and biologists in Utrecht and Pasadena began to cooperatively study plant growth...
September 2017: History and Philosophy of the Life Sciences
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