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The flotation and adsorption of mixed collectors on oxide and silicate minerals. Adv Colloid Interface Sci 2017; 250:1-14. [PMID: 29150015 DOI: 10.1016/j.cis.2017.11.003] [Citation(s) in RCA: 59] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2017] [Revised: 11/06/2017] [Accepted: 11/06/2017] [Indexed: 11/24/2022]
Abstract
The analysis of flotation and adsorption of mixed collectors on oxide and silicate minerals is of great importance for both industrial applications and theoretical research. Over the past years, significant progress has been achieved in understanding the adsorption of single collectors in micelles as well as at interfaces. By contrast, the self-assembly of mixed collectors at liquid/air and solid/liquid interfaces remains a developing area as a result of the complexity of the mixed systems involved and the limited availability of suitable analytical techniques. In this work, we systematically review the processes involved in the adsorption of mixed collectors onto micelles and at interface by examining four specific points, namely, theoretical background, factors that affect adsorption, analytical techniques, and self-assembly of mixed surfactants at the mineral/liquid interface. In the first part, the theoretical background of collector mixtures is introduced, together with several core solution theories, which are classified according to their application in the analysis of physicochemical properties of mixed collector systems. In the second part, we discuss the factors that can influence adsorption, including factors related to the structure of collectors and environmental conditions. We summarize their influence on the adsorption of mixed systems, with the objective to provide guidance on the progress achieved in this field to date. Advances in measurement techniques can greatly promote our understanding of adsorption processes. In the third part, therefore, modern techniques such as optical reflectometry, neutron scattering, neutron reflectometry, thermogravimetric analysis, fluorescence spectroscopy, ultrafiltration, atomic force microscopy, analytical ultracentrifugation, X-ray photoelectron spectroscopy, Vibrational Sum Frequency Generation Spectroscopy and molecular dynamics simulations are introduced in virtue of their application. Finally, focusing on oxide and silicate minerals, we review and summarize the flotation and adsorption of three most widely used mixed surfactant systems (anionic-cationic, anionic-nonionic, and cationic-nonionic) at the liquid/mineral interface in order to fully understand the self-assembly progress. In the end, the paper gives a brief future outlook of the possible development in the mixed surfactants.
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327
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Zhou X, Lu T, Zhu Y, Zhao G, Dong H, Jia Z, Yang Y, Chen Y, Xu B. Surface Morphology Evolution Mechanisms of InGaN/GaN Multiple Quantum Wells with Mixture N 2/H 2-Grown GaN Barrier. NANOSCALE RESEARCH LETTERS 2017; 12:354. [PMID: 28511535 PMCID: PMC5433960 DOI: 10.1186/s11671-017-2115-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/12/2017] [Accepted: 04/27/2017] [Indexed: 06/07/2023]
Abstract
Surface morphology evolution mechanisms of InGaN/GaN multiple quantum wells (MQWs) during GaN barrier growth with different hydrogen (H2) percentages have been systematically studied. Ga surface-diffusion rate, stress relaxation, and H2 etching effect are found to be the main affecting factors of the surface evolution. As the percentage of H2 increases from 0 to 6.25%, Ga surface-diffusion rate and the etch effect are gradually enhanced, which is beneficial to obtaining a smooth surface with low pits density. As the H2 proportion further increases, stress relaxation and H2 over- etching effect begin to be the dominant factors, which degrade surface quality. Furthermore, the effects of surface evolution on the interface and optical properties of InGaN/GaN MQWs are also profoundly discussed. The comprehensive study on the surface evolution mechanisms herein provides both technical and theoretical support for the fabrication of high-quality InGaN/GaN heterostructures.
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328
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Liu J, Guo N, Xiao X, Zhang K, Jia Y, Zhou S, Wu Y, Li Q, Xiao L. Pronounced Photovoltaic Response from Multi-layered MoTe 2 Phototransistor with Asymmetric Contact Form. NANOSCALE RESEARCH LETTERS 2017; 12:603. [PMID: 29168001 PMCID: PMC5700014 DOI: 10.1186/s11671-017-2373-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2017] [Accepted: 11/14/2017] [Indexed: 05/23/2023]
Abstract
In this study, we fabricate air-stable p-type multi-layered MoTe2 phototransistor using Au as electrodes, which shows pronounced photovoltaic response in off-state with asymmetric contact form. By analyzing the spatially resolved photoresponse using scanning photocurrent microscopy, we found that the potential steps are formed in the vicinity of the electrodes/MoTe2 interface due to the doping of the MoTe2 by the metal contacts. The potential step dominates the separation of photoexcited electron-hole pairs in short-circuit condition or with small V sd biased. Based on these findings, we infer that the asymmetric contact cross-section between MoTe2-source and MoTe2-drain electrodes is the reason to form non-zero net current and photovoltaic response. Furthermore, MoTe2 phototransistor shows a faster response in short-circuit condition than that with higher biased V sd within sub-millisecond, and its spectral range can be extended to the infrared end of 1550 nm.
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329
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Chaturvedi D, Mahalakshmi R. Position-Specific contribution of interface tryptophans on membrane protein energetics. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2017; 1860:451-457. [PMID: 29128310 DOI: 10.1016/j.bbamem.2017.11.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/14/2017] [Revised: 10/11/2017] [Accepted: 11/07/2017] [Indexed: 02/06/2023]
Abstract
Interface tryptophans are key residues that facilitate the folding and stability of membrane proteins. Escherichia coli OmpX possesses two unique interface tryptophans, namely Trp76, which is present at the interface and is solvent-exposed, and Trp140, which is relatively more lipid solvated than Trp76 in symmetric lipid membranes. Here, we address the requirement for tryptophan and the consequences of aromatic amino acid substitutions on the folding and stability of OmpX. Using spectroscopic measurements of OmpX-Trp/Tyr/Phe mutants, we show that the specific mutation W76→Y allows barrel assembly >1.5-fold faster than native OmpX, and increases stability by ~0.4kcalmol-1. In contrast, mutating W140→F/Y lowers OmpX thermodynamic stability by ~0.4kcalmol-1, without affecting the folding kinetics. We conclude that the stabilizing effect of tryptophan at the membrane interface can be position-and local environment-specific. We propose that the thermodynamic contributions for interface residues be interpreted with caution.
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330
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Cremeans MM, Devlin JF. Validation of a new device to quantify groundwater-surface water exchange. JOURNAL OF CONTAMINANT HYDROLOGY 2017; 206:75-80. [PMID: 29050851 DOI: 10.1016/j.jconhyd.2017.08.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2017] [Revised: 08/02/2017] [Accepted: 08/06/2017] [Indexed: 06/07/2023]
Abstract
Distributions of flow across the groundwater-surface water interface should be expected to be as complex as the geologic deposits associated with stream or lake beds and their underlying aquifers. In these environments, the conventional Darcy-based method of characterizing flow systems (near streams) has significant limitations, including reliance on parameters with high uncertainties (e.g., hydraulic conductivity), the common use of drilled wells in the case of streambank investigations, and potentially lengthy measurement times for aquifer characterization and water level measurements. Less logistically demanding tools for quantifying exchanges across streambeds have been developed and include drive-point mini-piezometers, seepage meters, and temperature profiling tools. This project adds to that toolbox by introducing the Streambed Point Velocity Probe (SBPVP), a reusable tool designed to quantify groundwater-surface water interactions (GWSWI) at the interface with high density sampling, which can effectively, rapidly, and accurately complement conventional methods. The SBPVP is a direct push device that measures in situ water velocities at the GWSWI with a small-scale tracer test on the probe surface. Tracer tests do not rely on hydraulic conductivity or gradient information, nor do they require long equilibration times. Laboratory testing indicated that the SBPVP has an average accuracy of ±3% and an average precision of ±2%. Preliminary field testing, conducted in the Grindsted Å in Jutland, Denmark, yielded promising agreement between groundwater fluxes determined by conventional methods and those estimated from the SBPVP tests executed at similar scales. These results suggest the SBPVP is a viable tool to quantify groundwater-surface water interactions in high definition in sandy streambeds.
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331
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Kruusimagi M, Sharples S, Robinson D. Living with an autonomous spatiotemporal home heating system: Exploration of the user experiences (UX) through a longitudinal technology intervention-based mixed-methods approach. APPLIED ERGONOMICS 2017; 65:286-308. [PMID: 28802449 DOI: 10.1016/j.apergo.2017.06.017] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2016] [Revised: 02/01/2017] [Accepted: 06/23/2017] [Indexed: 06/07/2023]
Abstract
Rising energy demands place pressure on domestic energy consumption, but savings can be delivered through home automation and engaging users with their heating and energy behaviours. The aim of this paper is to explore user experiences (UX) of living with an automated heating system regarding experiences of control, understanding of the system, emerging thermal behaviours, and interactions with the system as this area is not sufficiently researched in the existing homes setting through extended deployment. We present a longitudinal deployment of a quasi-autonomous spatiotemporal home heating system in three homes. Users were provided with a smartphone control application linked to a self-learning heating algorithm. Rich qualitative and quantitative data presented here enabled a holistic exploration of UX. The paper's contribution focuses on highlighting key aspects of UX living with an automated heating systems including (i) adoption of the control interface into the social context, (ii) how users' vigilance in maintaining preferred conditions prevailed as a better indicator of system over-ride than gross deviation from thermal comfort, (iii) limited but motivated proactivity in system-initiated communications as best strategy for soliciting user feedback when inference fails, and (iv) two main motivations for interacting with the interface - managing irregularities when absent from the house and maintaining immediate comfort, latter compromising of a checking behaviour that can transit to a system state alteration behaviour depending on mismatches. We conclude by highlighting the complex socio-technical context in which thermal decisions are made in a situated action manner, and by calling for a more holistic, UX-focused approach in the design of automated home systems involving user experiences.
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332
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Guo J, Li C, Ling S, Huang W, Chen Y, Kaplan DL. Multiscale design and synthesis of biomimetic gradient protein/biosilica composites for interfacial tissue engineering. Biomaterials 2017; 145:44-55. [PMID: 28843732 PMCID: PMC5610098 DOI: 10.1016/j.biomaterials.2017.08.025] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2017] [Revised: 07/16/2017] [Accepted: 08/14/2017] [Indexed: 01/13/2023]
Abstract
Continuous gradients present at tissue interfaces such as osteochondral systems, reflect complex tissue functions and involve changes in extracellular matrix compositions, cell types and mechanical properties. New and versatile biomaterial strategies are needed to create suitable biomimetic engineered grafts for interfacial tissue engineering. Silk protein-based composites, coupled with selective peptides with mineralization domains, were utilized to mimic the soft-to-hard transition in osteochondral interfaces. The gradient composites supported tunable mineralization and mechanical properties corresponding to the spatial concentration gradient of the mineralization domains (R5 peptide). The composite system exhibited continuous transitions in terms of composition, structure and mechanical properties, as well as cytocompatibility and biodegradability. The gradient silicified silk/R5 composites promoted and regulated osteogenic differentiation of human mesenchymal stem cells in an osteoinductive environment in vitro. The cells differentiated along the composites in a manner consistent with the R5-gradient profile. This novel biomimetic gradient biomaterial design offers a useful approach to meet a broad range of needs in regenerative medicine.
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333
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Mechanical behavior of biopolymer composite coatings on plastic films by depth-sensing indentation - A nanoscale study. J Colloid Interface Sci 2017; 512:638-646. [PMID: 29102910 DOI: 10.1016/j.jcis.2017.10.108] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2017] [Revised: 10/24/2017] [Accepted: 10/29/2017] [Indexed: 11/23/2022]
Abstract
Fundamental physical behaviors of materials at the nanoscale level are crucial when local aspects govern the macroscale performance of nanocomposites, e.g., interface and surface phenomena. Because of the increasing interest in biopolymer nanocomposite coatings for many different applications (e.g., optical devices, displays/screens, and packaging), this work investigates the potential of nanoindentation as a method for clarifying the interplay between distinct phases (i.e., organic and inorganic) at local level in thin biopolymer films loaded with nanoparticles. The nanomechanical features of pullulan nanocomposite coatings laid on polyethylene terephthalate (PET) were quantified in terms of elastic modulus (E), hardness (H), and creep (C) through an instrumented indentation test composed of a loading-holding-unloading cycle. Colloidal silica (CS) and cellulose nanocrystals (CNCs) were used as spherical and rod-like nanoparticles, respectively. An overall reinforcing effect was shown for all nanocomposite coatings over the pristine (unfilled) pullulan coating. A size effect was also disclosed for the CS-loaded surfaces, with the highest E value recorded for the largest particles (8.19 ± 0.35 GPa) and the highest H value belonging to the smallest ones (395.41 ± 25.22 MPa). Comparing CS and CNCs, the addition of spherical nanoparticles had a greater effect on the surface hardness than cellulose nanowhiskers (353.50 ± 83.52 MPa and 321.36 ± 43.26 MPa, respectively). As for the elastic modulus, the addition of CS did not provide any improvement over both the bare and CNC-loaded pullulan coatings, whereas the coating including CNCs exhibited higher E values (p < .05). Finally, CS-loaded pullulan coatings were the best performing in terms of C properties, with an average indentation depth of 16.5 ± 1.85 nm under a load of ∼190 μN. These results are discussed in terms of local distribution gradients, surface chemistry of nanoparticles, and how nanoparticle aggregation occurred in the dry nanocomposite coatings.
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Qiu W, Ma Z, Patel D, Sang L, Cai C, Shahriar Al Hossain M, Cheng Z, Wang X, Dou SX. The Interface Structure of FeSe Thin Film on CaF 2 Substrate and its Influence on the Superconducting Performance. ACS APPLIED MATERIALS & INTERFACES 2017; 9:37446-37453. [PMID: 29019397 DOI: 10.1021/acsami.7b11853] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The investigations into the interfaces in iron selenide (FeSe) thin films on various substrates have manifested the great potential of showing high-temperature-superconductivity in this unique system. In present work, we obtain FeSe thin films with a series of thicknesses on calcium fluoride (CaF2) (100) substrates and glean the detailed information from the FeSe/CaF2 interface by using scanning transmission electron microscopy (STEM). Intriguingly, we have found the universal existence of a calcium selenide (CaSe) interlayer with a thickness of approximate 3 nm between FeSe and CaF2 in all the samples, which is irrelevant to the thickness of FeSe layers. A slight Se deficiency occurs in the FeSe layer due to the formation of CaSe interlayer. This Se deficiency is generally negligible except for the case of the ultrathin FeSe film (8 nm in thickness), in which the stoichiometric deviation from FeSe is big enough to suppress the superconductivity. Meanwhile, in the overly thick FeSe layer (160 nm in thickness), vast precipitates are found and recognized as Fe-rich phases, which brings about degradation in superconductivity. Consequently, the thickness dependence of superconducting transition temperature (Tc) of FeSe thin films is investigated and one of our atmosphere-stable FeSe thin film (127 nm) possesses the highest Tconset/Tczero as 15.1 K/13.4 K on record to date in the class of FeSe thin film with practical thickness. Our results provide a new perspective for exploring the mechanism of superconductivity in FeSe thin film via high-resolution STEM. Moreover, approaches that might improve the quality of FeSe/CaF2 interfaces are also proposed for further enhancing the superconducting performance in this system.
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335
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Colaco BM, Olson EJ, Kolla BP, Forde IC, Mansukhani MP. A simple intervention that markedly reduces the effectiveness of positive airway pressure. Sleep Med 2017; 40:103-105. [PMID: 29221770 DOI: 10.1016/j.sleep.2017.08.025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/12/2017] [Revised: 08/24/2017] [Accepted: 08/28/2017] [Indexed: 11/16/2022]
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336
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Preparation and characterization of flexible lithium iron phosphate/graphene/cellulose electrode for lithium ion batteries. J Colloid Interface Sci 2017; 512:398-403. [PMID: 29096099 DOI: 10.1016/j.jcis.2017.10.042] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2017] [Revised: 09/28/2017] [Accepted: 10/11/2017] [Indexed: 11/20/2022]
Abstract
In this work, a free-standing flexible composite electrode was prepared by vacuum filtration method with LiFePO4, graphene and nanofibrillated cellulose (NFC). Compared with the pure LiFePO4 electrode, the resulting flexible composite (LiFePO4/graphene/NFC) electrode showed excellent mechanical flexibility, and possessed an enhanced initial discharge capacity of 151 mA h/g (0.1 C) and a good capacity retention rate with only 5% loss after 60 cycles due to suitable electrolyte wettability at the interface. Furthermore, the NFC and graphene formed a three-dimensional conductive framework, which provided high-speed electron conduction in the composite and reduced electrode polarization during charging-discharging processes. Moreover, the composite electrode could endure bending tests up to 1000 times, highlighting preferable mechanical strength and durability. These results demonstrated that the as-fabricated electrodes could be applied as flexible electrodes with an embedded power supply.
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337
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Hao L, Liu Y, Han Z, Xu Z, Zhu J. Large Lateral Photovoltaic Effect in MoS 2/GaAs Heterojunction. NANOSCALE RESEARCH LETTERS 2017; 12:562. [PMID: 29019043 PMCID: PMC5635143 DOI: 10.1186/s11671-017-2334-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/08/2017] [Accepted: 09/30/2017] [Indexed: 05/22/2023]
Abstract
Molybdenum disulfide (MoS2) nanoscaled films are deposited on GaAs substrates via magnetron sputtering technique, and MoS2/GaAs heterojunctions are fabricated. The lateral photovoltaic effect (LPE) of the fabricated MoS2/GaAs heterojunctions is investigated. The results show that a large LPE can be obtained in the MoS2/n-GaAs heterojunction. The LPE exhibits a linear dependence on the position of the laser illumination and the considerably high sensitivity of 416.4 mV mm-1. This sensitivity is much larger than the values in other reported MoS2-based devices. Comparatively, the LPE in the MoS2/p-GaAs heterojunction is much weaker. The mechanisms to the LPE are unveiled by constructing the energy-band alignment of the MoS2/GaAs heterojunctions. The excellent LPE characteristics make MoS2 films combined with GaAs semiconductors promising candidates for the application of high-performance position-sensitive detectors.
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338
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Grant JS, Shaw SK. A model system to mimic environmentally active surface film roughness and hydrophobicity. CHEMOSPHERE 2017; 185:772-779. [PMID: 28735233 DOI: 10.1016/j.chemosphere.2017.07.068] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2017] [Revised: 06/28/2017] [Accepted: 07/13/2017] [Indexed: 06/07/2023]
Abstract
This work presents the development and initial assessment of a laboratory platform to allow quantitative studies on model urban films. The platform consists of stearic acid and eicosane mixtures that are solution deposited from hexanes onto smooth, solid substrates. We show that this model has distinctive capabilities to better mimic a naturally occurring film's morphology and hydrophobicity, two important parameters that have not previously been incorporated into model film systems. The physical and chemical properties of the model films are assessed using a variety of analytical instruments. The film thickness and roughness are probed via atomic force microscopy while the film composition, wettability, and water uptake are analyzed by Fourier transform infrared spectroscopy, contact angle goniometry, and quartz crystal microbalance, respectively. Simulated environmental maturation is achieved by exposing the film to regulated amounts of UV/ozone. Ultimately, oxidation of the film is monitored by the analytical techniques mentioned above and proceeds as expected to produce a utile model film system. Including variable roughness and tunable surface coverage results in several key advantages over prior model systems, and will more accurately represent native urban film behavior.
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339
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Conroy D, Matar OK. Dynamics and stability of three-dimensional ferrofluid films in a magnetic field. JOURNAL OF ENGINEERING MATHEMATICS 2017; 107:253-268. [PMID: 32009673 PMCID: PMC6959396 DOI: 10.1007/s10665-017-9938-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/12/2017] [Accepted: 08/12/2017] [Indexed: 06/10/2023]
Abstract
We consider the interfacial dynamics of a thin, ferrofluid film flowing down an inclined substrate, under the action of a magnetic field, bounded above by an inviscid gas. The fluid is assumed to be weakly conducting, and its dynamics are governed by a coupled system of the steady Maxwell, Navier-Stokes, and continuity equations. The magnetization of the film is a function of the magnetic field, and is prescribed by a Langevin function. We make use of a long-wave reduction in order to solve for the dynamics of the pressure, velocity, and magnetic fields inside the film. The potential in the gas phase is solved by means of Fourier Transforms. Imposition of appropriate interfacial conditions allows for the construction of an evolution equation for the interfacial shape, via use of the kinematic condition, and the magnetic field. We study the three-dimensional evolution of the film to spanwise perturbations by solving the nonlinear equations numerically. The constant-volume configuration is considered, which corresponds to a slender drop flowing down an incline. A parametric study is then performed to understand the effect of the magnetic field on the stability and structure of the interface.
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340
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Vincent CJ, Blandford A. Bags, batteries and boxes: A qualitative interview study to understand how syringe drivers are adapted and used by healthcare staff. APPLIED ERGONOMICS 2017; 63:115-122. [PMID: 28502400 DOI: 10.1016/j.apergo.2017.04.012] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2016] [Revised: 02/19/2017] [Accepted: 04/16/2017] [Indexed: 06/07/2023]
Abstract
Syringe drivers are medical devices that are critical for end of life care. They deliver continuous medication over extended periods of time. Their design contributes to the quality of experience for both patients and healthcare professionals. Little research has been published about the factors that influence the usability of this type of equipment for frontline users (i.e. those in direct contact with patients) and how equipment gets introduced. Understanding how syringe drivers are used in practice can help improve the design of equipment. 27 semi-structured interviews were conducted across acute hospitals, community hospitals and hospices (4 organisations in total). All participating organisations used the same type of syringe driver. It was found that frontline staff needed to adapt this equipment to fit the circumstances of use. The analysis provided examples of this happening for aspects relating to the appearance of the device (bags), accessories (batteries) and security (the lockable box).
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341
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Bian L, Li YJ, Li J, Nie JN, Dong FQ, Song MX, Wang LS, Dong HL, Li HL, Nie XQ, Zhang XY, Li XX, Xie L. Photovoltage response of (XZn)Fe 2O 4-BiFeO 3 (X=Mg, Mn or Ni) interfaces for highly selective Cr 3+, Cd 2+, Co 2+ and Pb 2+ ions detection. JOURNAL OF HAZARDOUS MATERIALS 2017; 336:174-187. [PMID: 28494305 DOI: 10.1016/j.jhazmat.2017.04.071] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2017] [Revised: 04/13/2017] [Accepted: 04/28/2017] [Indexed: 06/07/2023]
Abstract
High-photostability fluorescent (XZn)Fe2O4 (X=Mg, Mn or Ni) embedded in BiFeO3 spinel-perovskite nanocomposites were successfully fabricated via a novel bio-induced phase transfer method using shewanella oneidensis MR-1. These nanocomposites have the near-infrared fluorescence response (XZn or Fe)-O-O-(Bi) interfaces (785/832nm), and the (XZn)Fe2O4/BiFeO3 lattices with high/low potentials (572.15-808.77meV/206.43-548.1meV). Our results suggest that heavy metal ion (Cr3+, Cd2+, Co2+ and Pb2+) d↓ orbitals hybridize with the paired-spin X-Zn-Fe d↓-d↓-d↑↓ orbitals to decrease the average polarization angles (-29.78 to 44.71°), qualitatively enhancing the photovoltage response selective potentials (39.57-487.84meV). The fluorescent kinetic analysis shows that both first-order and second-order equilibrium adsorption isotherms are in line and meet the Langmuir and Freundlich modes. Highly selective fluorescence detection of Co2+, Cr3+ and Cd2+ can be achieved using Fe3O4-BiFeO3 (Langmuir mode), (MgZn)Fe2O4-BiFeO3 and (MnZn)Fe2O4-BiFeO3 (Freundlich mode), respectively. Where the corresponding max adsorption capacities (qmax) are 1.5-1.94, 35.65 and 43.7 multiple, respectively, being more competitive than that of other heavy metal ions. The present bio-synthesized method might be relevant for high-photostability fluorescent spinel-perovskite nanocomposites, for design of heavy metal ion sensors.
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Ndengu M, Matope G, de Garine-Wichatitsky M, Tivapasi M, Scacchia M, Bonfini B, Pfukenyi DM. Seroprevalence of brucellosis in cattle and selected wildlife species at selected livestock/wildlife interface areas of the Gonarezhou National Park, Zimbabwe. Prev Vet Med 2017; 146:158-165. [PMID: 28992921 DOI: 10.1016/j.prevetmed.2017.08.004] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2017] [Revised: 07/12/2017] [Accepted: 08/04/2017] [Indexed: 01/01/2023]
Abstract
A study was conducted to investigate seroprevalence and risk factors for Brucella species infection in cattle and some wildlife species in communities living at the periphery of the Great Limpopo Transfrontier Conservation Area in south eastern Zimbabwe. Three study sites were selected based on the type of livestock-wildlife interface: porous livestock-wildlife interface (unrestricted); non-porous livestock-wildlife interface (restricted by fencing); and livestock-wildlife non-interface (totally absent or control). Sera were collected from cattle aged≥2years representing both female and intact male animals. Sera were also collected from selected wild ungulates from Mabalauta (porous interface) and Chipinda (non-interface) areas of the Gonarezhou National Park. Samples were screened for Brucellaantibodies using the Rose Bengal plate test and confirmed by the complement fixation test. Data were analysed by descriptive statistics and multivariate logistic regression modelling. In cattle, brucellosis seroprevalence from all areas was 16.7% (169/1011; 95% CI: 14.5-19.2%). The porous interface recorded a significantly (p=0.03) higher seroprevalence (19.5%; 95% CI: 16.1-23.4%) compared to the non-interface area (13.0%; 95% CI: 9.2-19.9%).The odds of Brucellaseropositivity increased progressively with parity of animals and were also three times higher (OR=3.0, 2.0<OR<4.6, p<0.0001) in cows with history of abortion compared to those without.Brucella antibodies were detected in buffaloes; 20.7% (95% CI: 13.9-29.7%) form both study sites, but no antibodies were detected from impalas and kudus. These results highlight the importance of porous interface in the interspecies transmission of Brucella species and that independent infections may be maintained in buffalo populations. Thus, brucellosis control aimed at limiting animal inter-species mixing may help reduce the risk of human brucellosis in interface areas. Further studies should aim at establishing subspecies identity and direction of possible transmission of brucellosis between wildlife and livestock.
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Skoblin MG, Chudinov AV, Sulimenkov IV, Brusov VS, Makarov AA, Wouters ER, Kozlovskiy VI. Numerical simulation of ion transport in an atmosphere-to-vacuum interface taking into account gas dynamics and space charge. EUROPEAN JOURNAL OF MASS SPECTROMETRY (CHICHESTER, ENGLAND) 2017; 23:187-191. [PMID: 29028401 DOI: 10.1177/1469066717719556] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
A two-step approach was developed for the study of ion transport in an atmospheric pressure interface. In the first step, the flow in the interface was numerically simulated using the standard gas dynamic package ANSYS CFX 15.0. In the second step, the calculated fields of pressure, temperature, and velocity were imported into a custom-built software application for simulation of ion motion under the influence of both gas dynamic and electrostatic forces. To account for space charge effects in axially symmetric interfaces an analytical expression was used for the Coulomb force. For all other types of interfaces, an iterative approach for the Coulomb force computation was developed. The simulations show that the influence of the space charge is the main contributor to the loss of ion current in the heated capillary. In addition, the maximum ion current which can be transmitted through the heated capillary (0.58 mm inner diameter and 58.5 mm length) is limited to ∼6 nA for ions with m/z = 508 Da and with reduced ion mobility 1.05 cm2V-1s-1. This limit remains practically constant and independent of the ion current at the entrance of the capillary. For a particular ion type, this limit depends on its m/z ratio and ion mobility.
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Glade N, Bastien O, Ballet P. Diversity and survival of artificial lifeforms under sedimentation and random motion. Theory Biosci 2017; 136:153-167. [PMID: 28721495 DOI: 10.1007/s12064-017-0254-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2017] [Accepted: 07/08/2017] [Indexed: 10/19/2022]
Abstract
Cellular automata are often used to explore the numerous possible scenarios of what could have occurred at the origins of life and before, during the prebiotic ages, when very simple molecules started to assemble and organise into larger catalytic or informative structures, or to simulate ecosystems. Artificial self-maintained spatial structures emerge in cellular automata and are often used to represent molecules or living organisms. They converge generally towards homogeneous stationary soups of still-life creatures. It is hard for an observer to believe they are similar to living systems, in particular because nothing is moving anymore within such simulated environments after few computation steps, because they present isotropic spatial organisation, because the diversity of self-maintained morphologies is poor, and because when stationary states are reached the creatures are immortal. Natural living systems, on the contrary, are composed of a high diversity of creatures in interaction having limited lifetimes and generally present a certain anisotropy of their spatial organisation, in particular frontiers and interfaces. In the present work, we propose that the presence of directional weak fields such as gravity may counter-balance the excess of mixing and disorder caused by Brownian motion and favour the appearance of specific regions, i.e. different strata or environmental layers, in which physical-chemical conditions favour the emergence and the survival of self-maintained spatial structures including living systems. We test this hypothesis by way of numerical simulations of a very simplified ecosystem model. We use the well-known Game of Life to which we add rules simulating both sedimentation forces and thermal agitation. We show that this leads to more active (vitality and biodiversity) and robust (survival) dynamics. This effectively suggests that coupling such physical processes to reactive systems allows the separation of environments into different milieux and could constitute a simple mechanism to form ecosystem frontiers or elementary interfaces that would protect and favour the development of fragile auto-poietic systems.
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Škvor J, Škvára J, Jirsák J, Nezbeda I. A general method for determining molecular interfaces and layers. J Mol Graph Model 2017; 76:17-35. [PMID: 28668730 DOI: 10.1016/j.jmgm.2017.05.016] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2017] [Revised: 05/22/2017] [Accepted: 05/23/2017] [Indexed: 11/30/2022]
Abstract
A general and direct computational scheme to locate the surface separating arbitrarily shaped domains made up of molecules (or any other particles) has been developed and is described and illustrated for several, both artificial and physical examples. The proposed scheme consists of two modules: (i) triangulation and (ii) assignment of simplices to domains. Three different triangulation methods are employed, viz., the Delaunay triangulation, regular triangulation, and quasi-triangulation. In the triangulated system, the assignment step is carried out in two different ways, one based on the characteristic metric of a particular triangulation procedure and the other on the concept of a touching sphere. Some of the combinations of the triangulation and assignment steps lead to methods already used by others to find interfacial or surface molecules, namely the alpha-shape-based method of Usabiaga nad Duque [Phys. Rev. E 79 (2009) 046709] and GITIM of Sega et al. [J. Chem. Phys. 138 (2013) 044110]. The resulting surface is defined not only as a discrete set of particles, but it is build up of facets of the triangulation forming a broken line in two dimensions or a polyhedral surface in three dimensions. Individual molecular layers are identified in a very straightforward manner, starting with the interfacial layer itself and proceeding into the interior of the phase. The proposed scheme is illustrated first by identifying border molecules of pre-sampled domains of several shapes in a plane and then applied to five physically meaningful examples: thin films, near critical water, liquid water slab in an electric field, liquid water at a solid wall, and water at condition of electric-field-induced jetting. Performance of the considered methods is critically assessed. Treatment of domains forming percolating clusters through periodic boundary conditions is also described along with the determination of their periodicity and dimensionality.
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Sampson R, MacVicar R, Wilson P. Improving the primary-secondary care interface in Scotland: a qualitative exploration of impact on clinicians of an educational complex intervention. BMJ Open 2017; 7:e016593. [PMID: 28652293 PMCID: PMC5541474 DOI: 10.1136/bmjopen-2017-016593] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
OBJECTIVES To determine the impact on clinicians and any consequent influence on patient care of taking part in the bespoke interface-focused educational intervention. DESIGN Qualitative design. SETTING Primary and secondary care centres in NHS Highland health board area, Scotland. PARTICIPANTS 33 urban-based clinicians (18 general practitioners and 15 hospital specialists) in NHS Highland, Scotland. INTERVENTION An interface-focused educational intervention was carried out in primary and secondary care centres in NHS Highland health board area, Scotland. Eligible clinicians were invited to take part in the intervention which involved facilitated small group work, and use of a bespoke educational module. Subsequent one-to-one interviews explored the impact of the intervention. A standard thematic analysis was used, comprising an iterative process based on grounded theory. RESULTS Key themes that emerged included fresh insights (in relation to those individuals and processes across the interface), adoption of new behaviours (eg, being more empowered to directly contact a colleague, taking steps to reduce the others workload and changes in professional approach) and changes in terms of communication (including a desire to communicate more effectively, with use of different modes and methods). CONCLUSION The study highlighted key areas that may serve as useful outcomes for a large-scale randomised trial. Addressing issues identified in the study may help to improve interface relationships and benefit patient care.
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Frank T, Krieger A, Leonard S, Patel NA, Tokuda J. ROS-IGTL-Bridge: an open network interface for image-guided therapy using the ROS environment. Int J Comput Assist Radiol Surg 2017; 12:1451-1460. [PMID: 28567563 DOI: 10.1007/s11548-017-1618-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2017] [Accepted: 05/18/2017] [Indexed: 01/18/2023]
Abstract
PURPOSE With the growing interest in advanced image-guidance for surgical robot systems, rapid integration and testing of robotic devices and medical image computing software are becoming essential in the research and development. Maximizing the use of existing engineering resources built on widely accepted platforms in different fields, such as robot operating system (ROS) in robotics and 3D Slicer in medical image computing could simplify these tasks. We propose a new open network bridge interface integrated in ROS to ensure seamless cross-platform data sharing. METHODS A ROS node named ROS-IGTL-Bridge was implemented. It establishes a TCP/IP network connection between the ROS environment and external medical image computing software using the OpenIGTLink protocol. The node exports ROS messages to the external software over the network and vice versa simultaneously, allowing seamless and transparent data sharing between the ROS-based devices and the medical image computing platforms. RESULTS Performance tests demonstrated that the bridge could stream transforms, strings, points, and images at 30 fps in both directions successfully. The data transfer latency was <1.2 ms for transforms, strings and points, and 25.2 ms for color VGA images. A separate test also demonstrated that the bridge could achieve 900 fps for transforms. Additionally, the bridge was demonstrated in two representative systems: a mock image-guided surgical robot setup consisting of 3D slicer, and Lego Mindstorms with ROS as a prototyping and educational platform for IGT research; and the smart tissue autonomous robot surgical setup with 3D Slicer. CONCLUSION The study demonstrated that the bridge enabled cross-platform data sharing between ROS and medical image computing software. This will allow rapid and seamless integration of advanced image-based planning/navigation offered by the medical image computing software such as 3D Slicer into ROS-based surgical robot systems.
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Current approaches for modulation of the nanoscale interface in the regulation of cell behavior. NANOMEDICINE-NANOTECHNOLOGY BIOLOGY AND MEDICINE 2017; 14:2455-2464. [PMID: 28552647 PMCID: PMC6173683 DOI: 10.1016/j.nano.2017.03.020] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/23/2016] [Revised: 02/20/2017] [Accepted: 03/09/2017] [Indexed: 11/22/2022]
Abstract
Regulation of cell behavior in response to nanoscale features has been the focus of much research in recent years and the successful generation of nanoscale features capable of mimicking the natural nanoscale interface has been of great interest in the field of biomaterials research. In this review, we discuss relevant nanofabrication techniques and how they are combined with bioengineering applications to mimic the natural extracellular matrix (ECM) and create valuable nanoscale interfaces.
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Sampson R, MacVicar R, Wilson P. Development of an interface-focused educational complex intervention. EDUCATION FOR PRIMARY CARE 2017; 28:265-273. [PMID: 28394242 DOI: 10.1080/14739879.2017.1309690] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
BACKGROUND In many countries, the medical primary-secondary care interface is central to the delivery of quality patient care. There is prevailing interest in developing initiatives to improve interface working for the benefit of health care professionals and their patients. AIM To describe the development of an educational intervention designed to improve working at the primary-secondary care interface in NHS Scotland (United Kingdom) within the context of the Medical Research Council framework for the development and evaluation of complex interventions. METHODS A primary-secondary care interface focused Practice-based Small Group Learning (PBSGL) module was developed building upon qualitative synthesis and original research. A 'meeting of experts' shaped the module, which was subsequently piloted with a group of interface clinicians. Reflections on the module were sought from clinicians across NHS Scotland to provide contextual information from other areas. FINDINGS The PBSGL approach can be usefully applied to the development of a primary-secondary care interface-focused medical educational intervention.
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Scherrer SS, Lohbauer U, Della Bona A, Vichi A, Tholey MJ, Kelly JR, van Noort R, Cesar PF. ADM guidance-Ceramics: guidance to the use of fractography in failure analysis of brittle materials. Dent Mater 2017; 33:599-620. [PMID: 28400062 DOI: 10.1016/j.dental.2017.03.004] [Citation(s) in RCA: 113] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2017] [Accepted: 03/09/2017] [Indexed: 11/16/2022]
Abstract
OBJECTIVES To provide background information and guidance as to how to use fractography accurately, a powerful tool for failure analysis of dental ceramic structures. METHODS An extended palette of qualitative and quantitative fractography is provided, both for in vivo and in vitro fracture surface analyses. As visual support, this guidance document will provide micrographs of typical critical ceramic processing flaws, differentiating between pre- versus post sintering cracks, grinding damage related failures and occlusal contact wear origins and of failures due to surface degradation. RESULTS The documentation emphasizes good labeling of crack features, precise indication of the direction of crack propagation (dcp), identification of the fracture origin, the use of fractographic photomontage of critical flaws or flaw labeling on strength data graphics. A compilation of recommendations for specific applications of fractography in Dentistry is also provided. SIGNIFICANCE This guidance document will contribute to a more accurate use of fractography and help researchers to better identify, describe and understand the causes of failure, for both clinical and laboratory-scale situations. If adequately performed at a large scale, fractography will assist in optimizing the methods of processing and designing of restorative materials and components. Clinical failures may be better understood and consequently reduced by sending out the correct message regarding the fracture origin in clinical trials.
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