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https://www.readbyqxmd.com/read/28532025/new-tetrahedral-zinc-halide-schiff-base-complexes-synthesis-crystal-structure-theoretical-3d-hirshfeld-surface-analyses-antimicrobial-and-thermal-studies
#1
L Taghizadeh, M Montazerozohori, A Masoudiasl, S Joohari, J M White
A new bidentate Schiff base ligand named as N,N'-bis((E)-3-phenylallylidene)butane-1,4-diamine (L) and three its zinc halide complexes were synthesized and characterized by FT-IR, (1)H NMR, (13)C NMR and UV-Vis spectroscopy. The crystal structure of zinc bromide and iodide complexes were characterized using single crystal X-ray diffraction. The two structures are isomorphous, crystallizing in the monoclinic crystal system with space group C2/c with closely similar unit cell dimensions. In these complexes, the Zn(II) ion is in the center of a distorted tetrahedral environment completed by two iminic nitrogen atoms of Schiff base ligand and two halide anions...
August 1, 2017: Materials Science & Engineering. C, Materials for Biological Applications
https://www.readbyqxmd.com/read/28531219/pyldm-an-open-source-package-for-lifetime-density-analysis-of-time-resolved-spectroscopic-data
#2
Gabriel F Dorlhiac, Clyde Fare, Jasper J van Thor
Ultrafast spectroscopy offers temporal resolution for probing processes in the femto- and picosecond regimes. This has allowed for investigation of energy and charge transfer in numerous photoactive compounds and complexes. However, analysis of the resultant data can be complicated, particularly in more complex biological systems, such as photosystems. Historically, the dual approach of global analysis and target modelling has been used to elucidate kinetic descriptions of the system, and the identity of transient species respectively...
May 22, 2017: PLoS Computational Biology
https://www.readbyqxmd.com/read/28530810/seleniranium-ions-undergo-%C3%AF-ligand-exchange-via-an-associative-mechanism-in-the-gas-phase
#3
Shea Fern Lim, Benjamin Leigh Harris, George N Khairallah, Evan John Bieske, Philippe Maître, Gabriel da Silva, Brian D Adamson, Michael S Scholz, Neville J A Coughlan, Richard A J O'Hair, Michael Rathjen, Daniel Stares, Jonathan M White
Collision-induced dissociation mass spectrometry of the ammonium ions 4a and 4b results in the formation of the seleniranium ion 5, the structure and purity of which was verified using gas phase infra-red spectroscopy coupled to mass spectrometry, and gas phase ion-mobility measurements. Ion-molecule reactions between the ion 5 (m/z = 261) and cyclopentene, cyclohexene, cycloheptene and cyclooctene, resulted in the formation of the seleniranium ions 7 (m/z = 225), 6 (m/z = 239), 8 (m/z = 253), and 9 (m/z = 267) respectively...
May 22, 2017: Journal of Organic Chemistry
https://www.readbyqxmd.com/read/28530418/is-political-behavior-a-viable-coping-strategy-to-perceived-organizational-politics-unveiling-the-underlying-resource-dynamics
#4
Shuhua Sun, Huaizhong Chen
We conduct a theory-driven empirical investigation on whether political behavior, as a coping strategy to perceived organizational politics, creates resource trade-offs in moderating the relationship between perceived organizational politics and task performance. Drawing on conservation of resources theory, we hypothesize that political behavior mitigates the adverse effect of perceived organizational politics on task performance via psychological empowerment, yet exacerbates its adverse effect on task performance via emotional exhaustion...
May 22, 2017: Journal of Applied Psychology
https://www.readbyqxmd.com/read/28530269/a-critical-comparison-of-coarse-grained-structure-based-approaches-and-atomic-models-of-protein-folding
#5
Jie Hu, Tao Chen, Moye Wang, Hue Sun Chan, Zhuqing Zhang
Structure-based coarse-grained Gō-like models have been used extensively in deciphering protein folding mechanisms because of their simplicity and tractability. Meanwhile, explicit-solvent molecular dynamics (MD) simulations with physics-based all-atom force fields have been applied successfully to simulate folding/unfolding transitions for several small, fast-folding proteins. To explore the degree to which coarse-grained Gō-like models and their extensions to incorporate nonnative interactions are capable of producing folding processes similar to those in all-atom MD simulations, here we systematically compare the computed unfolded states, transition states, and transition paths obtained using coarse-grained models and all-atom explicit-solvent MD simulations...
May 22, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28530242/interface-driven-formation-of-a-two-dimensional-dodecagonal-fullerene-quasicrystal
#6
M Paßens, V Caciuc, N Atodiresei, M Feuerbacher, M Moors, R E Dunin-Borkowski, S Blügel, R Waser, S Karthäuser
Since their discovery, quasicrystals have attracted continuous research interest due to their unique structural and physical properties. Recently, it was demonstrated that dodecagonal quasicrystals could be used as bandgap materials in next-generation photonic devices. However, a full understanding of the formation mechanism of quasicrystals is necessary to control their physical properties. Here we report the formation of a two-dimensional dodecagonal fullerene quasicrystal on a Pt3Ti(111) surface, which can be described in terms of a square-triangle tiling...
May 22, 2017: Nature Communications
https://www.readbyqxmd.com/read/28530167/biofilm-community-succession-a-neutral-perspective
#7
Stephen Woodcock, William T Sloan
Although biofilms represent one of the dominant forms of life in aqueous environments, our understanding of the assembly and development of their microbial communities remains relatively poor. In recent years, several studies have addressed this and have extended the concepts of succession theory in classical ecology into microbial systems. From these datasets, niche-based conceptual models have been developed explaining observed biodiversity patterns and their dynamics. These models have not, however, been formulated mathematically and so remain untested...
May 22, 2017: Microbiology
https://www.readbyqxmd.com/read/28529962/picosecond-sulfur-k-edge-x-ray-absorption-spectroscopy-with-applications-to-excited-state-proton-transfer
#8
Benjamin E Van Kuiken, Matthew R Ross, Matthew L Strader, Amy A Cordones, Hana Cho, Jae Hyuk Lee, Robert W Schoenlein, Munira Khalil
Picosecond X-ray absorption (XA) spectroscopy at the S K-edge (∼2.4 keV) is demonstrated and used to monitor excited state dynamics in a small organosulfur molecule (2-Thiopyridone, 2TP) following optical excitation. Multiple studies have reported that the thione (2TP) is converted into the thiol (2-Mercaptopyridine, 2MP) following photoexcitation. However, the timescale and photochemical pathway of this reaction remain uncertain. In this work, time-resolved XA spectroscopy at the S K-edge is used to monitor the formation and decay of two transient species following 400 nm excitation of 2TP dissolved in acetonitrile...
July 2017: Structural Dynamics (Melville, N.Y.)
https://www.readbyqxmd.com/read/28529756/a-socioecological-framework-for-research-on-work-and-obesity-in-diverse-urban-transit-operators-based-on-gender-race-and-ethnicity
#9
REVIEW
BongKyoo Choi, Peter Schnall, Marnie Dobson, Haiou Yang, Dean Baker, YoungJu Seo
Urban transit (bus and rail) operators, totaling nearly 700,000 persons, are one of the heaviest occupational groups in the United States (US). Little is known about occupational risk factors for weight gain and obesity and their interrelationship with health-related behaviors, particularly among female minority (African Americans and Hispanics) transit operators who are at greater risk for obesity. As a step towards developing successful obesity interventions among urban transit operators, this paper aims to present a new socioecological framework for studying working conditions, chronic strain, health-related behaviors, weight gain/obesity, and obesity disparity in diverse urban transit operators based on gender, race, and ethnicity...
2017: Annals of Occupational and Environmental Medicine
https://www.readbyqxmd.com/read/28529720/recent-advances-in-metacommunities-and-meta-ecosystem-theories
#10
REVIEW
Frédéric Guichard
Metacommunity theory has provided many insights into the general problem of local versus regional control of species diversity and relative abundance. The metacommunity framework has been extended from competitive interactions to whole food webs that can be described as spatial networks of interaction networks. Trophic metacommunity theory greatly contributed to resolving the community complexity-stability debate by predicting its dependence on the regional spatial context. The meta-ecosystem framework has since been suggested as a useful simplification of complex ecosystems to apply this spatial context to spatial flows of both individuals and matter...
2017: F1000Research
https://www.readbyqxmd.com/read/28527450/on-the-accuracy-of-one-and-two-particle-solvation-entropies
#11
Benedict W J Irwin, David J Huggins
Evaluating solvation entropies directly and combining with direct energy calculations is one way of calculating free energies of solvation and is used by Inhomogeneous Fluid Solvation Theory (IFST). The configurational entropy of a fluid is a function of the interatomic correlations and can thus be expressed in terms of correlation functions. The entropies in this work are directly calculated from a truncated series of integrals over these correlation functions. Many studies truncate all terms higher than the solvent-solute correlations...
May 21, 2017: Journal of Chemical Physics
https://www.readbyqxmd.com/read/28527373/-i-don-t-believe-it-acceptance-and-skepticism-of-genetic-health-information-among-african-american-and-white-smokers
#12
Erika A Waters, Linda Ball, Sarah Gehlert
RATIONALE: Effective translation of genomics research into practice depends on public acceptance of genomics-related health information. OBJECTIVE: To explore how smokers come to accept or reject information about the relationship between genetics and nicotine addiction. METHODS: Thirteen focus groups (N = 84) were stratified by education (seven < Bachelor's degree, six ≥ Bachelor's degree) and race (eight black, five white). Participants viewed a 1-min video describing the discovery of a genetic variant associated with increased risk of nicotine addiction and lung cancer...
May 3, 2017: Social Science & Medicine
https://www.readbyqxmd.com/read/28526269/nanoscale-analysis-of-the-oxidation-state-and-surface-termination-of-praseodymium-oxide-ultrathin-films-on-ruthenium-0001
#13
J I Flege, J-O Krisponeit, J Höcker, M Hoppe, Y Niu, A Zakharov, A Schaefer, J Falta, E E Krasovskii
The complex structure and morphology of ultrathin praseodymia films deposited on a ruthenium(0001) single crystal substrate by reactive molecular beam epitaxy is analyzed by intensity-voltage low-energy electron microscopy in combination with theoretical calculations within an ab initio scattering theory. A rich coexistence of various nanoscale crystalline surface structures is identified for the as-grown samples, notably comprising two distinct oxygen-terminated hexagonal Pr2O3(0001) surface phases as well as a cubic Pr2O3(111) and a fluorite PrO2(111) surface component...
May 10, 2017: Ultramicroscopy
https://www.readbyqxmd.com/read/28525951/perfect-spin-filter-in-a-tailored-zigzag-graphene-nanoribbon
#14
Dawei Kang, Bowen Wang, Caijuan Xia, Haisheng Li
Zigzag graphene nanoribbons (ZGNRs) are expected to serve as the promising component in the all-carbon spintronic device. It remains challenging to fabricate a device based on ZGNRs with high spin-filter efficiency and low experimental complexity. Using density functional theory combined with nonequilibrium Green's function technique, we studied the spin-dependent transport properties of the tailored zigzag graphene nanoribbon. A perfect spin-filtering effect is found in the tailored structure of ZGNR. The nearly 100% spin-polarized current and high magneto-resistance ratio can be obtained by applying a homogeneous magnetic field across the device...
December 2017: Nanoscale Research Letters
https://www.readbyqxmd.com/read/28525776/from-liability-to-challenge-complex-environments-are-associated-with-favorable-psychosocial-outcomes-in-adolescent-sport-participants
#15
Enrique García Bengoechea, Philip M Wilson, Steven Dunn
This study aimed to identify different groups of adolescents who have distinct profiles based upon their perceptions of interpersonal and activity-based dimensions of the sport environment. A sample of 310 adolescents from Eastern Canada (Mage = 14.69 ± 1.60 years; 54.8% girls) completed questionnaires assessing selected interpersonal, activity-based, demographic and sport-specific variables. Using TwoStep Cluster Analysis, we identified three groupings of adolescent sport participants. Consistent with the literature, we labeled these groups 'negative context,' 'positive context,' and 'complex context,' respectively...
May 16, 2017: Journal of Adolescence
https://www.readbyqxmd.com/read/28525573/noreva-normalization-and-evaluation-of-ms-based-metabolomics-data
#16
Bo Li, Jing Tang, Qingxia Yang, Shuang Li, Xuejiao Cui, Yinghong Li, Yuzong Chen, Weiwei Xue, Xiaofeng Li, Feng Zhu
Diverse forms of unwanted signal variations in mass spectrometry-based metabolomics data adversely affect the accuracies of metabolic profiling. A variety of normalization methods have been developed for addressing this problem. However, their performances vary greatly and depend heavily on the nature of the studied data. Moreover, given the complexity of the actual data, it is not feasible to assess the performance of methods by single criterion. We therefore developed NOREVA to enable performance evaluation of various normalization methods from multiple perspectives...
May 19, 2017: Nucleic Acids Research
https://www.readbyqxmd.com/read/28525272/direct-synthesis-of-an-unprecedented-stable-radical-of-nickel-ii-3-5-bis-dimedonyl-azadiisoindomethene-with-strong-and-narrow-near-infrared-absorption-at-%C3%AE-%C3%A2-1000-nm
#17
Elena A Makarova, Yuriy V Zatsikha, Kelly M E Newman, Vinod K Paidi, Valeria A Beletsky, Johan van Lierop, Evgeny A Lukyanets, Victor N Nemykin
An unprecedented stable neutral radical nickel(II) complex of 3,5-bis(dimedonyl)azadiisoindomethene (1) was prepared by the direct reaction between 1,3-diiminoisoindoline and dimedone. A new radical complex 1 has an intense and narrow absorption at 1008 nm and can be reduced to a less stable anionic [1](-) with a typical aza(dibenzo)boron dipyrromethene (aza-BODIPY) UV-vis spectrum. Complex 1, along with two other colored condensation reaction products 2 and 3, was characterized by spectroscopy and X-ray crystallography, while the paramagnetic nature of 1 was probed by EPR and SQUID methods...
May 19, 2017: Inorganic Chemistry
https://www.readbyqxmd.com/read/28524924/a-theoretical-study-on-the-mechanistic-highlights-behind-the-br%C3%A3-nsted-acid-dependent-mer-fac-isomerization-of-homoleptic-carbenic-iridium-complexes-for-pholeds
#18
Tobias Setzer, Christian Lennartz, Andreas Dreuw
Recently, a successful Brønsted-acid mediated geometric isomerization of the meridional homoleptic carbenic iridium(iii) complexes tris-(N-phenyl,N-methyl-benzimidazol-2-yl)iridium(iii) (1) and tris-(N-phenyl,N-benzyl-benzimidazol-2-yl)iridium(iii) (2) into their facial form has been reported. In the present work the pronounced acid-dependency of this particular isomerization procedure is revisited and additional mechanistic pathways are taken into account. Moreover, the acid-induced material decomposition is addressed...
May 19, 2017: Dalton Transactions: An International Journal of Inorganic Chemistry
https://www.readbyqxmd.com/read/28524871/in-situ-light-responses-of-the-proteorhodopsin-bearing-antarctic-sea-ice-bacterium-psychroflexus-torques
#19
David J Burr, Andrew Martin, Elizabeth W Maas, Ken G Ryan
Proteorhodopsin (PR) is a wide-spread protein found in many marine prokaryotes. PR allows for the potential conversion of solar energy to ATP, possibly assisting in cellular growth and survival during periods of high environmental stress. PR utilises either blue or green light through a single amino acid substitution. We incubated the PR-bearing bacterium Psychroflexus torquis 50 cm deep within Antarctic sea ice for 13 days, exposing cultures to diurnal fluctuations in light and temperature. Enhanced growth occurred most prominently in cultures incubated under irradiance levels of ∼50 μmol photons m(-2) s(-1), suggesting PR provides a strong selective advantage...
May 19, 2017: ISME Journal
https://www.readbyqxmd.com/read/28523607/carotenoid-to-bacteriochlorophyll-energy-transfer-through-vibronic-coupling-in-lh2-from-phaeosprillum-molischianum
#20
Erling Thyrhaug, Craig N Lincoln, Federico Branchi, Giulio Cerullo, Václav Perlík, František Šanda, Heiko Lokstein, Jürgen Hauer
The peripheral light-harvesting antenna complex (LH2) of purple photosynthetic bacteria is an ideal testing ground for models of structure-function relationships due to its well-determined molecular structure and ultrafast energy deactivation. It has been the target for numerous studies in both theory and ultrafast spectroscopy; nevertheless, certain aspects of the convoluted relaxation network of LH2 lack a satisfactory explanation by conventional theories. For example, the initial carotenoid-to-bacteriochlorophyll energy transfer step necessary on visible light excitation was long considered to follow the Förster mechanism, even though transfer times as short as 40 femtoseconds (fs) have been observed...
May 18, 2017: Photosynthesis Research
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