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1.
In order to analyze whether impairments to health and well‐being under flexible working hours can be predicted from specific characteristics of the work schedules, periodic components in flexible working hours and their interference with the circadian temperature rhythm were analyzed applying univariate and bivariate spectrum analyses to both time series. The resulting indicators of spectral power and phase shift of these components were then related to reported health impairments using regression analysis. The results show that a suppression of both the 24 and the 168 h components in the work schedules (i.e., a lack of periodicity) can be used to predict reported health impairments, and that if there are relatively strong 24 and 168 h components left in the work schedules, their phase difference with the temperature rhythm (as an indicator of the interference between working time and the circadian rhythm) further predicts impairment. The results indicate that the periodicity of working hours and the amount of (circadian) desynchronization induced by flexible work schedules can be used for predicting the impairing effects of flexible work schedules on health and well‐being. The results can thus be used for evaluating and designing flexible shift rosters.  相似文献   
2.
Abstract

We compare molecular dynamics simulation results for the properties of liquid water predicted by four novel water potential models. These models are designed as a combination of parameters taken from the dedicated but brittle TIP3P water potential, and the more flexible but less accurate parameterisations such as the Dreiding and Universal force fields. We find that a hybrid of Dreiding and TIP3P delivers the best results, yielding a density, diffusion coefficient and radial distribution function in good agreement with experiment, performing in some respects even better than the dedicated reference TIP3P model. Another Dreiding based force field predicts semi-quantitative results for the water structure and dynamics while the Universal force field based models are incapable of simulating a condensed phase of water at all, continuing to expand indefinitely. These observations are useful for selecting and designing robust water force field parameterisations that can be used for general simulation purposes.  相似文献   
3.
X-ray diffraction data on a few retroviral integrases show a flexible loop near the active site. By sequence alignment, the peptide region 207-218 of Mo-MLV IN appears to correspond to this flexible loop. In this study, residues H208, Y211, R212, Q214, S215 and S216 of Mo-MLV IN were mutated to determine their role on enzyme activity. We found that Y211A, R212A, R212K and Q214A decreased integration activity, while disintegration and 3′-processing were not significantly affected. By contrast H208A was completely inactive in all the assays. The core domain of Mo-MLV integrase was modeled and the flexibility of the region 207-216 was analyzed. Substitutions with low integration activity showed a lower flexibility than wild type integrase. We propose that the peptide region 207-216 is a flexible loop and that H208, Y211, R212 and Q214 of this loop are involved in the correct assembly of the DNA-integrase complex during integration.  相似文献   
4.
Abstract

A numerical model of the coupled motion of a flexing surface in a high Reynolds number flow is presented for the simulation of flexible polyurethane heart valves in the aortic position. This is achieved by matching a Lagrangian dynamic leaflet model with a panel method based flow solver. The two models are coupled via the time-dependent pressure field using the unsteady Bernoulli equation.

Incorporation of sub-cycling in the dynamic model equations and fast pre conditioning techniques in the panel method solver yields efficient convergence and near real-time simulations of valve motion. The generality of dynamic model allows different material properties and/or geometries to be studied easily and interactively. This interactivity is realized by embedding the models within a design environment created using the software IRIS Explorer TM.

Two flow domains are developed, an infinite domain and an internal domain using conformal mapping theory. In addition bending stress on the valve is computed using a simple stress model based on spline and circle equation techniques.  相似文献   
5.
Human dUTPase, essential for DNA integrity, is an important survival factor for cancer cells. We determined the crystal structure of the enzyme:alpha,beta-imino-dUTP:Mg complex and performed equilibrium binding experiments in solution. Ordering of the C-terminus upon the active site induces close juxtaposition of the incoming nucleophile attacker water oxygen and the alpha-phosphorus of the substrate, decreasing their distance below the van der Waals limit. Complex interactions of the C-terminus with both substrate and product were observed via a specifically designed tryptophan sensor, suitable for further detailed kinetic and ligand binding studies. Results explain the key functional role of the C-terminus.  相似文献   
6.
A new organic-inorganic hybrid solid with 3-D framework, [Mn(DMF)3]2[Re6Se8(CN)6] (1), has been synthesized and transformed to [H][Mn(salen)]3[Re6Se8(CN)6] (2) by a ligand exchange. Hexarhenium chalcocyanide clusters are closest packed in cubic symmetry for 1 and rhombohedral symmetry for 2. The manganese complexes in the interstitial sites are three-coordinated to the rhenium cluster in 1 and two-coordinated in 2.  相似文献   
7.
The coordination chemistry of three selected copper(II) salts with the flexible ligand 1,4-bis(1,2,4-triazol-1-yl)butane (abbreviated as btb) is described. This ligand acts as a bidentate ligand, bridging copper(II) ions, thereby generating polymers in 2D and 3D network solids.  相似文献   
8.
Four new coordination networks based on dipyridyl linkages 2,6-(N,N′-di(4-pyridyl)amino)pyridine (dpap) or 1,3-bis(4-pyridyl)propane (bpp) and different dicarboxylates have been synthesized and structurally characterized. Using dpap to react with two different dicarboxylates, maleic acid (H2mal) and 4,4′-sulfonyldibenzoate (H2sdba), respectively, two different two-dimensional (2D) coordination polymers of Cd(II), [Cd(dpap)(mal)]n (1) and {[Cd(dpap)(sdba)] · 2H2O}n (2) were obtained. Compound 1 features a 42-membered bimetallic macrocyclic structural motif which is extended by mal groups to form a 2D network. In the case of 2, two different layers can be achieved depending on the conformation of sdba. The layer has a (8210) net topology with Cd as nodes and dpap, sdba bridges as the connectors. The overall structure of {[Mn(dpap)(sdba)] · 1.5H2O}n (3) similar to that of 2 despite the presence of different metal ions. When dpap was replaced by bpp to react with Co(NO3)2 · 6H2O, another 1D coordination polymer, {[Co(bpp)(H2O)4] · sdba}n(4) was constructed. The 1D chains join sdba to make an overall 3D supramolecular architecture by hydrogen-bonding interactions ( (22), (12)). The Cd coordination polymers exhibit strong solid-state luminescence emission at room temperature. Thermal stability of these crystalline materials has been explored by thermogravimetric analysis of mass loss.  相似文献   
9.
A series of flexible multidentate ligands containing N,P-donor, 2-[N-(diphenylphosphino)methyl]amino-pyridine (L1), 2-[N-bi-(diphenylphosphino) methyl]amino-pyridine (L2), 2-[N-(diphenylphosphino)methyl]amino-7-methyl-1,8-naphthyridine (L3) and 4-[(N-diphenylphosphino)methyl]amino-pyridine) (L4) have been synthesized. The mono- and dinuclear cyclometalated platinum(II) complexes [Pt(C^N^N)L1]ClO4 (HC^N^N = 6-phenyl-2,2′-bipyridine), [Pt2(C^N^N)2L1](ClO4)2, [Pt2(C^N^N)2L2](ClO4)2, [Pt(C^N^N)L3]ClO4 and [Pt2(C^N^N)2L4](ClO4)2 were prepared and their structures determined by X-ray crystal analysis. These complexes exhibit long-lived bright orange emissions ranging from 560 to 610 nm in the solid state at room temperature. In solution, dinuclear complexes have emissions with higher quantum yields than mononuclear complexes. This can be attributed to intramolecular interaction of free functional group with Pt(II) at axial position, resulting in the quenching of phosphorescence for platinum(II) complexes in the 3MLCT excited state.  相似文献   
10.
Two novel metal-organic hybrid coordination polymers {[Cu(bpo)(chdc)(H2O)](H2O)0.5}n (1) and [Pb(chdc)(H2O)]n (2) have been synthesized under different conditions and structurally characterized by single-crystal X-ray diffraction technique, where H2chdc refers to a flexible 1,4-cyclohexanedicarboxylic acid ligand and bpo is 2,5-bis(4-pyridyl)-1,3,4-oxadiazole. Complex 1 has a two-dimensional (2-D) grid-like [11.28 × 13.63 Å2] framework in which the CuII centers are extended via bidentate bridging ligands bpo and e,e-trans-chdc along two directions, exhibiting large porous cavities. Coordination polymer 2 represents the first PbII complex of H2chdc in which the larger PbII centers are connected by e,a-cis-chdc anions to afford a 2-D close-knit structure.  相似文献   
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