1,136 research outputs found

    The d(10) route to dye-sensitized solar cells: step-wise assembly of zinc(II) photosensitizers on TiO2 surfaces

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    Dye-sensitized solar cells have been assembled using a sequential approach: a TiO2 surface was functionalized with an anchoring ligand, followed by metallation with Zn(OAc)(2) or ZnCl2, and subsequent capping with a chromophore functionalized 2,2`:6`,2 ``-terpyridine; the DSCs exhibit surprisingly good efficiencies confirming the effectiveness of the new strategy for zinc-based DSC fabrication

    Native structure-based modeling and simulation of biomolecular systems per mouse click

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    Background Molecular dynamics (MD) simulations provide valuable insight into biomolecular systems at the atomic level. Notwithstanding the ever-increasing power of high performance computers current MD simulations face several challenges: the fastest atomic movements require time steps of a few femtoseconds which are small compared to biomolecular relevant timescales of milliseconds or even seconds for large conformational motions. At the same time, scalability to a large number of cores is limited mostly due to long-range interactions. An appealing alternative to atomic-level simulations is coarse-graining the resolution of the system or reducing the complexity of the Hamiltonian to improve sampling while decreasing computational costs. Native structure-based models, also called Gō-type models, are based on energy landscape theory and the principle of minimal frustration. They have been tremendously successful in explaining fundamental questions of, e.g., protein folding, RNA folding or protein function. At the same time, they are computationally sufficiently inexpensive to run complex simulations on smaller computing systems or even commodity hardware. Still, their setup and evaluation is quite complex even though sophisticated software packages support their realization. Results Here, we establish an efficient infrastructure for native structure-based models to support the community and enable high-throughput simulations on remote computing resources via GridBeans and UNICORE middleware. This infrastructure organizes the setup of such simulations resulting in increased comparability of simulation results. At the same time, complete workflows for advanced simulation protocols can be established and managed on remote resources by a graphical interface which increases reusability of protocols and additionally lowers the entry barrier into such simulations for, e.g., experimental scientists who want to compare their results against simulations. We demonstrate the power of this approach by illustrating it for protein folding simulations for a range of proteins. Conclusions We present software enhancing the entire workflow for native structure-based simulations including exception-handling and evaluations. Extending the capability and improving the accessibility of existing simulation packages the software goes beyond the state of the art in the domain of biomolecular simulations. Thus we expect that it will stimulate more individuals from the community to employ more confidently modeling in their research

    The Influence of Fatteners Dry and Liquid Diet on Slaughter Traits of Carcass Sides

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    The study was conducted on 700 fattening pigs, three breed half blood with Duroc as a terminal breed ((Large White x Landrace) x Duroc). The pigs were divided into the two groups according to diet: dry and liquid nutrition. Each group consisted of 350 fattening pigs and used the same feed mixtures in prefattening (CP-3) and fattening (ST). During the period from 24.8 to 60kg they were fed with a CP-3, a crude protein content of 16.37%. During the period from 60kg until the end they were fed with ST, a crude protein content of 15.3%. Muscle tissue processed half-carcasses in slaughterhouses were determined by a device that determines the value of S (fat thickness) and M (muscle thickness) using "method one point." Fat thickness skin in mm, measured 7 cm lateral to the central (median) cutting, in the amount between the second and third ribs of the tail. The thickness of the muscle in mm was measured at the same place as the thickness of the bacon. The results show that the fatling fed dry food had significantly higher carcass weight (80.41: 78.51 kg, p<0.05), backfat thickness (16.55: 15.31 mm, p<0.05), weight (muscle 55.80: 53.82, p<0.05), but a lower percentage of meat (56.6: 57.3, p<0.05) as compared to pigs fed liquid food. In finishing pigs fed dry food, between carcass weight and backfat thickness and muscle thickness a positive and significant correlation (0.4267 and 0.4290, p<0.05) was found and between carcass weight and lean meat a significant negative correlation (-0. 4236 and p<0.05). Between backfat thickness and lean meat in the carcass a negative and significant correlation (-0.8534, p<0.05) was found and between muscle thickness and lean meat a positive and significant correlation (0.2857, p<0.05). In finishing pigs fed liquid food, between carcass weight and backfat thickness and muscle thickness a positive and significant correlation (0.1800 and 0.3705, p<0.05) was found and between carcass weight and lean meat a significant negative correlation (-0. 2178; p <0.05). Between backfat thickness and percentage of meat in the carcass negative and significant correlation (-0.8692, p<0.05) was found and between muscle thickness and lean meat a positive and significant correlation (0.3168, p<0.05)

    Formation and Interaction of Membrane Tubes

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    We show that the formation of membrane tubes (or membrane tethers), which is a crucial step in many biological processes, is highly non-trivial and involves first order shape transitions. The force exerted by an emerging tube is a non-monotonic function of its length. We point out that tubes attract each other, which eventually leads to their coalescence. We also show that detached tubes behave like semiflexible filaments with a rather short persistence length. We suggest that these properties play an important role in the formation and structure of tubular organelles.Comment: 4 pages, 3 figure

    Copper(I) dye-sensitized solar cells with [Co(bpy)3]2+/3+ electrolyte

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    The hierarchical assembly of DSCs containing a new heteroleptic copper(I) complex with a phosphonic acid anchoring ligand is described; it is shown that conventional I−/I3− electrolytes may be replaced by [Co(bpy)3]2+/3+ with no loss in performance

    Peripheral halo-functionalization in [Cu(N^N)(P^P)]+ emitters: influence on the performances of light-emitting electrochemical cells

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    A series of heteroleptic [Cu(N^N)(P^P)][PF6] complexes is described in which P^P = bis(2-(diphenylphosphino)phenyl)ether (POP) or 4,5-bis(diphenylphosphino)-9,9-dimethylxanthene (xantphos) and N^N = 4,4′-diphenyl-6,6′-dimethyl-2,2′-bipyridine substituted in the 4-position of the phenyl groups with atom X (N^N = 1 has X = F, 2 has X = Cl, 3 has X = Br, 4 has X = I; the benchmark N^N ligand with X = H is 5). These complexes have been characterized by multinuclear NMR spectroscopy, mass spectrometry, elemental analyses and cyclic voltammetry; representative single crystal structures are also reported. The solution absorption spectra are characterized by high energy bands (arising from ligand-centred transitions) which are red-shifted on going from X = H to X = I, and a broad metal-to-ligand charge transfer band with λmax in the range 387–395 nm. The ten complexes are yellow emitters in solution and yellow or yellow-orange emitters in the solid-state. For a given N^N ligand, the solution photoluminescence (PL) spectra show no significant change on going from [Cu(N^N)(POP)]+ to [Cu(N^N)(xantphos)]+; introducing the iodo-functionality into the N^N domain leads to a red-shift in λmaxem compared to the complexes with the benchmark N^N ligand 5. In the solid state, [Cu(1)(POP)][PF6] and [Cu(1)(xantphos)][PF6] (fluoro-substituent) exhibit the highest PL quantum yields (74 and 25%, respectively) with values of τ1/2 = 11.1 and 5.8 μs, respectively. Light-emitting electrochemical cells (LECs) with [Cu(N^N)(P^P)][PF6] complexes in the emissive layer have been tested. Using a block-wave pulsed current driving mode, the best performing device employed [Cu(1)(xantphos)]+ and this showed a maximum luminance (Lummax) of 129 cd m−2 and a device lifetime (t1/2) of 54 h; however, the turn-on time (time to reach Lummax) was 4.1 h. Trends in performance data reveal that the introduction of fluoro-groups is beneficial, but that the incorporation of heavier halo-substituents leads to poor devices, probably due to a detrimental effect on charge transport; LECs with the iodo-functionalized N^N ligand 4 failed to show any electroluminescence after 50 h

    Implementation of patient-reported outcome measures in U.S. Total joint replacement registries: rationale, status, and plans

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    BACKGROUND: In the U.S. and abroad, the use of patient-reported outcome measures to evaluate the impact of total joint replacement surgery on patient quality of life is increasingly common. Analyses of patient-reported outcomes have documented substantial pain relief and functional gain among the vast majority of patients managed with total joint replacement. In addition, postoperative patient-reported outcomes are useful to identify persistent pain and suboptimal outcomes in the minority of patients who have them. The leaders of five U.S. total joint replacement registries report the rationale, current status, and vision for the use of patient-reported outcome measures in U.S. total joint replacement registries. METHODS: Surgeon leaders of the Function and Outcomes Research for Comparative Effectiveness in Total Joint Replacement registry, American Joint Replacement Registry, California Joint Replacement Registry, Michigan Arthroplasty Registry Collaborative Quality Initiative, and Virginia Joint Registry report the rationale supporting the adoption of patient-reported outcome measures, factors associated with the selection and successful implementation of patient-reported outcome measures, and barriers to complete and valid data. RESULTS: U.S. registries are at varied stages of implementation of preoperative surveys and postoperative total joint replacement outcome measures. Surgeon leaders report unified rationales for adopting patient-reported outcome measures: to capture data on pain relief and functional gain following total joint replacement as well as to identify suboptimal implant performance. Key considerations in the selection of a patient-reported outcome measure include its ability to measure both joint pain and physical function while limiting any burden on patients and surgeons related to its use. Complete patient-reported outcomes data will be associated with varied modes of survey completion, including options for home-based completion, to ensure consistent timing and data capture. CONCLUSIONS: The current stage of implementation of patient-reported outcome measures varies widely among U.S. registries. Nonetheless, evidence from the Function and Outcomes Research for Comparative Effectiveness in Total Joint Replacement registry supports the feasibility of successful implementation of patient-reported outcome measures with careful attention to the selection of the outcome measure, mode and timing of postoperative administration, and minimization of any burden on the patient and surgeon

    Understanding why replacing I3–/I– by cobalt(II)/(III) electrolytes in bis(diimine)copper(I)-based dye-sensitized solar cells improves performance

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    The performances of dye-sensitized solar cells (DSCs) comprising heteroleptic bis(diimine)copper( I ) based dyes combined with either [Co(bpy) 3 ] 2+/3+ , [Co(phen) 3 ] 2+/3+ or I 3 /I redox mediators (bpy 1/4 2,2 0 - bipyridine, phen 1/4 1,10-phenanthroline) have been evaluated. The copper( I ) dyes contain the anchoring ligand ((6,6 0 -dimethyl-[2,2 0 -bipyridine]-4,4 0 -diyl)bis(4,1-phenylene))bis(phosphonic acid), 1, and an ancillary ligand (2, 3 or 4) with a 2,9-dimethyl-1,10-phenanthroline metal-binding domain. Ligands 2 and 3 include imidazole 2 0 -functionalities with 4-(diphenylamino)phenyl (2) or 4-(bis(4-n-butoxy) phenylamino)phenyl (3) domains; in 4, the phen unit is substituted in the 4,7-positions with holetransporting 4-(diphenylamino)phenyl groups. The photoconversion efficiency, h, of each of [Cu(1)(2)] + , [Cu(1)(3)] + and [Cu(1)(4)] + considerably improves by replacing the I 3 /I electrolyte by [Co(bpy) 3 ] 2+/3+ or [Co(phen) 3 ] 2+/3+ , and after a change of electrolyte solvent (MeCN to 3-methoxypropionitrile). Due to the faster charge transfer kinetics and more positive redox potential, the cobalt-based electrolytes are superior to the I 3 /I electrolyte in terms of open-circuit voltage (V OC ), short-circuit current (J SC ) and h; values of V OC 1/4 594 mV, J SC 1/4 9.58 mA cm 2 and h 1/4 3.69% (relative to h 1/4 7.12% for N719) are achieved for the best performing DSC which contains [Cu(1)(4)] + and [Co(bpy) 3 ] 2+/3+ . Corresponding values for [Cu(1)(4)] + and I 3 /I DSCs are 570–580 mV, 5.98–6.37 mA cm 2 and 2.43–2.62%. Electrochemical impedance spectroscopy (EIS) has been used to study DSCs with [Cu(1)(4)] + and the three electrolytes. EIS shows that the DSC with I 3 /I has the highest recombination resistance, whereas the [Co(phen) 3 ] 2+/3+ electrolyte gives the highest chemical capacitance and V OC and, between [Co(bpy) 3 ] 2+/3+ and [Co(phen) 3 ] 2+/3+ , the higher recombination resistance. The [Co(phen) 3 ] 2+/3+ electrolyte exhibits the highest mass transport restrictions which result in a lower J SC and DSC efficiency compared to the [Co(bpy) 3 ] 2+/3+ electrolyte

    A rapid qPCR method to investigate the circulation of the yeast Wickerhamomyces anomalus in humans

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    The yeast Wickerhamomyces anomalus has been proposed for many biotechnological applications in the food industry. However, a number of opportunistic pathogenic strains have been reported as causative agents of nosocomial fungemia. Recognition of potentially pathogenic isolates is an important challenge for the future commercialization of this yeast. The isolation of W. anomalus from different matrices and, recently, from mosquitoes, requires further investigations into its circulation in humans. Here we present a qPCR protocol for the detection of W. anomalus in human blood samples and the results of a screening of 525 donors, including different classes of patients and healthy people
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