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“RSV frequency in children below 2 years hospitalized for lower respiratory tract infections”. Hacimustafaoglu M, Celebi S, Bozdemir SE, Ozgur T, Ozcan I, Guray A, Çakir D, Turkish Journal Of Pediatrics 55, 130 (2013)
Abstract: Respiratory syncytial virus (RSV) is the most frequent agent of acute lower respiratory diseases and creates a significant burden of disease in children under 5 years all over the world. RSV causes severe lower respiratory tract infections (LRTI) that require hospitalization, especially in children <= 2 years. The aim of this study was to determine the incidence of RSV in children <= 2 years of age hospitalized for LRTI. Children <= 2 years of age hospitalized for one year for LRTI in the three largest hospitals of Bursa City Center, Turkey were evaluated. These three hospitals comprise 67.5% of all child beds in central Bursa, so this study allows us to evaluate the total disease burden and hospitalization incidence in central Bursa. Nasal swabs of the children were evaluated with RSV RespiStrip (Coris Bioconcept Organization). A total of 671 children were hospitalized for LRTI, and 254 (37.9%) had at least one hospitalization that was positive for RSV. Of all patients with LRTI, 54.8% (368/671) were hospitalized for acute bronchiolitis, while 45.2% (303/671) were hospitalized for pneumonia. Of patients with acute bronchiolitis or pneumonia, 41% (151/368) and 34% (103/303) were RSV+, respectively. Of RSV+ hospitalized children, 59.5% (151/254) were diagnosed as acute bronchiolitis and 40.5% (103/254) as pneumonia. The annual incidences of hospitalization due to LRTI, acute bronchiolitis and pneumonia were 20.5/1000, 11.2/1000 and 9.3/1000, respectively, in children <= 2 years of age. The annual incidences of hospitalization due to RSV+ LRTI, acute bronchiolitis and pneumonia were found as 7.8/1000, 4.6/1000 and 3.2/1000, respectively, in children <= 2 years of age. More than one-third of all children hospitalized with LRTI (38.3%, n=257) were in the 0-3 months age group. Compared to other age groups, RSV positivity was highest in that age group for acute bronchiolitis (57%), pneumonia (39.5%) and also total children with LRTI (47.9%). RSV is a very important cause of lower respiratory infections in children <= 2 years of age and occurred most frequently in those 0-3 months of age in our study. Since there is no other study assessing the annual hospitalization incidence of RSV+ LRTIs in one city in Turkey, our study has unique importance for providing valuable statistical data about RSV+ LRTIs.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 0.32
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“Electron diffraction measurement of the binding rigidity of free-standing graphene”. Kirilenko DA, Technical physics letters 39, 325 (2013). http://doi.org/10.1134/S1063785013040081
Abstract: A method for measuring the binding rigidity of free-standing graphene from the dependence of the short-wavelength spectral range of transverse structural fluctuations of a crystal is proposed. The fluctuation spectrum is measured according to the variation in electron-diffraction patterns derived in a transmission electron microscope while tilting the sample.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 0.771
Times cited: 3
DOI: 10.1134/S1063785013040081
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“Dedicated TEM on domain boundaries from phase transformations and crystal growth”. Schryvers D, Van Aert S, Delville R, Idrissi H, Turner S, Salje EKH, Phase transitions 86, 15 (2013). http://doi.org/10.1080/01411594.2012.694435
Abstract: Investigating domain boundaries and their effects on the behaviour of materials automatically implies the need for detailed knowledge on the structural aspects of the atomic configurations at these interfaces. Not only in view of nearest neighbour interactions but also at a larger scale, often surpassing the unit cell, the boundaries can contain structural elements that do not exist in the bulk. In the present contribution, a number of special boundaries resulting from phase transformations or crystal growth and those recently investigated by advanced transmission electron microscopy techniques in different systems will be reviewed. These include macrotwins between microtwinned martensite plates in NiAl, austenite-single variant martensite habit planes in low hysteresis NiTiPd, nanotwins in non-textured nanostructured Pd and ferroelastic domain boundaries in CaTiO3. In all discussed cases these boundaries play an essential role in the properties of the respective materials.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 1.06
DOI: 10.1080/01411594.2012.694435
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“Functional twin boundaries”. Van Aert S, Turner S, Delville R, Schryvers D, Van Tendeloo G, Ding X, Salje EKH, Phase transitions 86, 1052 (2013). http://doi.org/10.1080/01411594.2012.748909
Abstract: Functional interfaces are at the core of research in the emerging field of domain boundary engineering where polar, conducting, chiral, and other interfaces and twin boundaries have been discovered. Ferroelectricity was found in twin walls of paraelectric CaTiO3. We show that the effect of functional interfaces can be optimized if the number of twin boundaries is increased in densely twinned materials. Such materials can be produced by shear in the ferroelastic phase rather than by rapid quench from the paraelastic phase.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 1.06
Times cited: 5
DOI: 10.1080/01411594.2012.748909
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“Catheter-associated bloodstream infections in pediatric hematology-oncology patients”. Celebi S, Sezgin ME, Çakir D, Baytan B, Demirkaya M, Sevinir B, Bozdemir SE, Gunes AM, Hacimustafaoglu M, Pediatric Hematology And Oncology 30, 187 (2013). http://doi.org/10.3109/08880018.2013.772683
Abstract: Catheter-associated bloodstream infections (CABSIs) are common complications encountered with cancer treatment. The aims of this study were to analyze the factors associated with recurrent infection and catheter removal in pediatric hematology-oncology patients. All cases of CABSIs in patients attending the Department of Pediatric Hematology-Oncology between January 2008 and December 2010 were reviewed. A total of 44 episodes of CABSIs, including multiple episodes involving the same catheter, were identified in 31 children with cancer. The overall CABSIs rate was 7.4 infections per 1000 central venous catheter (CVC) days. The most frequent organism isolated was coagulase-negative Staphylococcus (CONS). The CVC was removed in nine (20.4%) episodes. We found that hypotension, persistent bacteremia, Candida infection, exit-side infection, neutropenia, and prolonged duration of neutropenia were the factors for catheter removal. There were 23 (52.2%) episodes of recurrence or reinfection. Mortality rate was found to be 9.6% in children with CABSIs. In this study, we found that CABSIs rate was 7.4 infections per 1000 catheter-days. CABSIs rates in our hematology-oncology patients are comparable to prior reports. Because CONS is the most common isolated microorganism in CABSIs, vancomycin can be considered part of the initial empirical regimen.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 1.12
DOI: 10.3109/08880018.2013.772683
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“Epitaxial chemical vapor deposition of silicon on an oxygen monolayer on Si(100) substrates”. Delabie A, Jayachandran S, Caymax M, Loo R, Maggen J, Pourtois G, Douhard B, Conard T, Meersschaut J, Lenka H, Vandervorst W, Heyns M;, ECS solid state letters 2, P104 (2013). http://doi.org/10.1149/2.009311ssl
Abstract: Crystalline superlattices consisting of alternating periods of Si layers and O-atomic layers are potential new channel materials for scaled CMOS devices. In this letter, we investigate Chemical Vapor Deposition (CVD) for the controlled deposition of O-atoms with O-3 as precursor on Si(100) substrates and Si epitaxy on the O-layer. The O-3 reaction at 50 degrees C on the H-terminated Si results in the formation of Si-OH and/or Si-O-Si-H surface species with monolayer O-content. Defect-free epitaxial growth of Si on an O-layer containing 6.4E+14 O-atoms/cm(2) is achieved from SiH4 at 500 degrees C. (C) 2013 The Electrochemical Society. All rights reserved.
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 1.184
Times cited: 12
DOI: 10.1149/2.009311ssl
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“Electric field tuning of the optical excitonic Aharonov-Bohm effect in nanodots grown by droplet epitaxy”. Arsoski V, Tadic M, Peeters FM, Physica scripta T157, 014002 (2013). http://doi.org/10.1088/0031-8949/2013/T157/014002
Abstract: Neutral excitons in axially symmetric GaAs nanodots embedded in an (Al, Ga) As matrix, which are formed by the droplet epitaxy technique, are investigated theoretically. An electric field perpendicular to the nanodot base results in both a vertical and an in-plane exciton polarization, which is beneficial for the appearance of the excitonic Aharonov-Bohm effect. In the range of low magnetic fields (below 5 Tesla), we found that the bright and dark exciton states can cross twice. This results in oscillations of the photoluminescence intensity with magnetic field, which are a striking manifestation of the optical excitonic Aharonov-Bohm effect.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 1.28
DOI: 10.1088/0031-8949/2013/T157/014002
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“Semi-quantitative analysis of the formation of a calcium oxalate protective layer for monumental limestone using combined micro-XRF and micro-XRPD”. Vanmeert F, Mudronja D, Fazinic S, Janssens K, Tibljas D, X-ray spectrometry 42, 256 (2013). http://doi.org/10.1002/XRS.2486
Abstract: A current method for the protection of cretaceous limestone present in various monuments consists of performing a passivating treatment with ammonium oxalate (AmOx). A calcium oxalate protective layer is formed on the surface and enhances the acid resistance of the stone. The in-depth formation of the calcium oxalate layer was investigated on cross sections by using combined micro X-ray fluorescence and micro X-ray powder diffraction (mu XRF/mu XRPD). XRPD showed the presence of both whewellite and weddellite in the calcite stone matrix. A correction was made for sample misalignment, which was visible in both the fluorescence and the diffraction line measurements. A semi-quantitative analysis was performed on the basis of Klug's equation for a two-phase mixture (the presence of weddellite was neglected) without the need for a known reference sample. By assuming two extreme compositions for a reference weight fraction (1 and 99wt%), it was possible to obtain whewellite concentration profiles, which can be used for comparing the effectiveness of different methods for the application of AmOx to the stone surface and the effect of treatment time and AmOx concentration used. It is shown that for the relative amounts of whewellite formed, the differences due to the assumed weight fractions are smaller than the errors due to sample heterogeneity and preferred orientation. Copyright (c) 2013 John Wiley & Sons, Ltd.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Impact Factor: 1.298
Times cited: 5
DOI: 10.1002/XRS.2486
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“Wafer-level electrical evaluation of vertical carbon nanotube bundles as a function of growth temperature”. Vereecke B, van der Veen MH, Sugiura M, Kashiwagi Y, Ke X, Cott DJ, Hantschel T, Huyghebaert C, Tökei Z, Japanese journal of applied physics 52, 04cn02 (2013). http://doi.org/10.7567/JJAP.52.04CN02
Abstract: We have evaluated the resistance of carbon nanotubes (CNTs) grown at a CMOS-compatible temperature using a realistic integration scheme. The structural analysis of the CNTs by transmission electron microscopy (TEM) showed that the degree of graphitization decreased significantly when the growth temperature was decreased from 540 to 400 °C. The CNTs were integrated to form 150-nm-diameter vertical interconnects between a TiN layer and Cu metal trenches on 200 mm full wafers. Wafers with CNTs grown at low temperature were found to have a lower single-contact resistance than those produced at high temperatures. Thickness measurements showed that the low contact resistance is a result of small contact height. This height dependence is masking the impact of CNT graphitization quality on resistance. When benchmarking our results with data from the literature, a relationship between resistivity and growth temperature cannot be found for CNT-based vertical interconnects.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 1.384
Times cited: 5
DOI: 10.7567/JJAP.52.04CN02
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“Low-dimensional confining structures on the surface of helium films suspended on designed cavities”. Dantas DS, Chaves A, Farias GA, Ramos ACA, Peeters FM, Journal of low temperature physics 173, 207 (2013). http://doi.org/10.1007/s10909-013-0895-5
Abstract: We investigate the formation of quantum confined structures on the surface of a liquid helium film suspended on a nanostructured substrate. We show theoretically that, by nanostructuring the substrate, it is possible to change the geometry of the liquid helium surface, opening the possibility of designing and controlling the formation of valleys with different shapes. By applying an external electric field perpendicular to the substrate plane, surface electrons can be trapped into these valleys, as in a quantum dot. We investigate how the external parameters, such as the electric field strength and the height of the liquid helium bath, can be tuned to control the energy spectrum of the trapped surface electrons.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 1.3
Times cited: 1
DOI: 10.1007/s10909-013-0895-5
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“Non-conventional vortex configurations in a mesoscopic flat disk”. Barba-Ortega J, Sardella E, Aguiar JA, Peeters FM, Physica: C : superconductivity 487, 47 (2013). http://doi.org/10.1016/j.physc.2013.01.021
Abstract: The influence of superficial defects on the vortex configurations of a thin superconducting disk is investigated within the time dependent Ginzburg-Landau formalism. The free energy, magnetization, vorticity, and the Cooper pair density are calculated for both metastable and stable vortex configurations and different number of defects on its surface in the presence of an external magnetic field applied perpendicular to the disk area. We show that the competition between the confinement geometry and the geometric position of the defects leads to non-conventional vortex configurations which are not compatible with the symmetry of the sample geometry. Crown Copyright (C) 2013 Published by Elsevier B.V. All rights reserved.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 1.404
Times cited: 17
DOI: 10.1016/j.physc.2013.01.021
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“Efficiency of applying ammonium oxalate for protection of monumental limestone by poultice, immersion and brushing methods”. Mudronja D, Vanmeert F, Hellemans K, Fazinic S, Janssens K, Tibljas D, Rogosic M, Jakovljevic S, Applied physics A : materials science &, processing 111, 109 (2013). http://doi.org/10.1007/S00339-012-7365-9
Abstract: Samples of cretaceous limestone have been treated with three application methods (poultice, immersion and brushing) using different concentrations of ammonium oxalate solution (AmOx) and varying treatment time in order to test the efficiency of surface and in-depth formation of a protective layer of calcium oxalate (CaOx). Synchrotron-based microanalytical techniques (SR-mu XRD with 12.5 mu mx7.5 mu m (HxV) probe size, SR-mu FTIR with 10 mu mx10 mu m and 8 mu mx20 mu m probe sizes) and laboratory mu FTIR, XRD and SEM have been employed for analysis of the treated samples. Synchrotron-based techniques showed variations in the CaOx distribution along the surface on a micrometer scale. All treatments resulted in the development of a CaOx layer with a maximum thickness of approximately 40 mu m. Application by the brushing method with 10 1-min applications with 5-min breaks during one hour showed a development of the calcium oxalate layer equivalent to the poultice treatment taking 10 h. This treatment could be preferred for large marble or limestone surfaces where poultice usage is economically not feasible.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Impact Factor: 1.455
Times cited: 13
DOI: 10.1007/S00339-012-7365-9
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“Scanning XRF investigation of a Flower Still Life and its underlying composition from the collection of the Kröller-Muller Museum”. Alfeld M, van der Snickt G, Vanmeert F, Janssens K, Dik J, Appel K, van der Loeff L, Chavannes M, Meedendorp T, Hendriks E, Applied physics A : materials science &, processing 111, 165 (2013). http://doi.org/10.1007/S00339-012-7526-X
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Impact Factor: 1.455
Times cited: 35
DOI: 10.1007/S00339-012-7526-X
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“Visualizing the 17th century underpainting in Portrait of an Old Man by Rembrandt van Rijn using synchrotron-based scanning macro-XRF”. Alfeld M, Siddons DP, Janssens K, Dik J, Woll A, Kirkham R, van de Wetering E, Applied physics A : materials science &, processing 111, 157 (2013). http://doi.org/10.1007/S00339-012-7490-5
Abstract: In 17th century Old Master Paintings, the underpainting generally refers to the first sketch of a composition. The underpainting is applied to a prepared ground using a monochrome, brown oil paint to roughly indicate light, shade and contours. So far, methods to visualize the underpainting-other than in localized cross-sections-have been very limited. Neither infrared reflectography nor neutron induced autoradiography have proven to be practical, adequate visualization tools. Thus, although of fundamental interest in the understanding of a painting's genesis, the underpainting has virtually escaped all imaging efforts. In this contribution we will show that 17th century underpainting may consist of a highly heterogeneous mixture of pigments, including copper pigments. We suggest that this brown pigment mixture is actually the recycled left-over of a palette scraping. With copper as the heaviest exclusive elemental component, we will hence show in a case study on a Portrait of an Old Man attributed to Rembrandt van Rijn how scanning macro-XRF can be used to efficiently visualize the underpainting below the surface painting and how this information can contribute to the discussion of the painting's authenticity.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Impact Factor: 1.455
Times cited: 26
DOI: 10.1007/S00339-012-7490-5
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“Electron-hole symmetry and solutions of Richardson pairing model”. Pogosov WV, Lin N, Misko VR, European physical journal : B : condensed matter and complex systems 86, 235 (2013). http://doi.org/10.1140/epjb/e2013-40234-9
Abstract: Richardson approach provides an exact solution of the pairing Hamiltonian. This Hamiltonian is characterized by the electron-hole pairing symmetry, which is however hidden in Richardson equations. By analyzing this symmetry and using an additional conjecture, fulfilled in solvable limits, we suggest a simple expression of the ground state energy for an equally-spaced energy-level model, which is applicable along the whole crossover from the superconducting state to the pairing fluctuation regime. Solving Richardson equations numerically, we demonstrate a good accuracy of our expression.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 1.461
Times cited: 6
DOI: 10.1140/epjb/e2013-40234-9
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“TEM investigation of the formation mechanism of deformation twins in Fe-Mn-Si-Al TWIP steels”. Idrissi H, Renard K, Schryvers D, Jacques PJ, Philosophical magazine 93, 4378 (2013). http://doi.org/10.1080/14786435.2013.832837
Abstract: The microstructure of a Fe-Mn-Si-Al twinning-induced plasticity (TWIP) steel exhibiting remarkable work hardening rate under uniaxial tensile deformation was investigated using transmission electron microscopy to uncover the mechanism(s) controlling the nucleation and growth of the mechanically induced twins. The results show that the stair-rod cross-slip deviation mechanism is necessary for the formation of the twins, while large extrinsic stacking faults homogenously distributed within the grains could act as preferential sources for the activation of the deviation process. The influence of such features on the thickness and strength of the twins and the resulting mechanical behaviour is discussed and compared to similar works recently performed on Fe-Mn-C TWIP steels.
Keywords: A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Impact Factor: 1.505
Times cited: 15
DOI: 10.1080/14786435.2013.832837
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“Scattering of Dirac electrons by a random array of magnetic flux tubes”. Masir MR, Peeters FM, Journal of computational electronics 12, 115 (2013). http://doi.org/10.1007/s10825-013-0440-4
Abstract: The scattering of two-dimensional (2D) massless electrons as presented in graphene in the presence of a random array of circular magnetic flux tubes is investigated. The momentum relaxation time and the Hall factor are obtained using optical theorem techniques for scattering. Electrons with energy close to those of the Landau levels of the flux tubes exhibit resonant scattering and have a long life-time to reside inside the magnetic flux tube. These resonances appear as sharp structures in the Hall factor and the magneto-resistance.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 1.526
Times cited: 2
DOI: 10.1007/s10825-013-0440-4
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“Pseudo magnetic field in strained graphene : revisited”. Masir MR, Moldovan D, Peeters FM, Solid state communications 175, 76 (2013). http://doi.org/10.1016/j.ssc.2013.04.001
Abstract: We revisit the theory of the pseudo magnetic field as induced by strain in graphene using the tight- binding approach. A systematic expansion of the hopping parameter and the deformation of the lattice vectors is presented from which we obtain an expression for the pseudo magnetic field for low energy electrons. We generalize and discuss previous results and propose a novel effective Hamiltonian. The contributions of the different terms to the pseudo field expression are investigated for a model triaxial strain profile and are compared with the full solution. Our work suggests that the previous proposed pseudo magnetic field expression is valid up to reasonably high strain (15%) and there is no K-dependent pseudo-magnetic field.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 1.554
Times cited: 57
DOI: 10.1016/j.ssc.2013.04.001
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“Phonon-assisted Zener tunneling in a p-n diode silicon nanowire”. Carrillo-Nunez H, Magnus W, Vandenberghe WG, Sorée B, Peeters FM, Solid state electronics 79, 196 (2013). http://doi.org/10.1016/j.sse.2012.09.004
Abstract: The Zener tunneling current flowing through a biased, abrupt p-n junction embedded in a cylindrical silicon nanowire is calculated. As the band gap becomes indirect for sufficiently thick wires, Zener tunneling and its related transitions between the valence and conduction bands are mediated by short-wavelength phonons interacting with mobile electrons. Therefore, not only the high electric field governing the electrons in the space-charge region but also the transverse acoustic (TA) and transverse optical (TO) phonons have to be incorporated in the expression for the tunneling current. The latter is also affected by carrier confinement in the radial direction and therefore we have solved the Schrodinger and Poisson equations self-consistently within the effective mass approximation for both conduction and valence band electrons. We predict that the tunneling current exhibits a pronounced dependence on the wire radius, particularly in the high-bias regime. (C) 2012 Elsevier Ltd. All rights reserved.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 1.58
Times cited: 2
DOI: 10.1016/j.sse.2012.09.004
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“Optoelectronic properties of ABC-stacked trilayer graphene”. Xiao YM, Xu W, Zhang YY, Peeters FM, Physica status solidi: B: basic research 250, 86 (2013). http://doi.org/10.1002/pssb.201248169
Abstract: We present a theoretical study on the optoelectronic properties of ABC-stacked trilayer graphene (TLG). The optical conductance and light transmittance are evaluated through using the energy-balance equation derived from the Boltzmann equation for an air/graphene/dielectric-wafer system in the presence of linearly polarized radiation field. The results obtained from two band structure models are examined and compared. For short wavelength radiation, the universal optical conductance sigma(0) = 3e(2)/(4h) can be obtained. Importantly, there exists an optical absorption window in the radiation wavelength range 10-200 mu m, which is induced by different transition energies required for inter- and intra-band optical absorption channels. As a result, we find that the position and width of this window depend sensitively on temperature and carrier density of the system, especially the lower frequency edge. There is a small characteristic absorption peak at about 82 mu m where the largest interband transition states exist in the ABC-stacked TLG model, in contrast to the relatively smooth curves in a simplified model. These theoretical results indicate that TLG has some interesting and important physical properties which can be utilized to realize infrared or THz optoelectronic devices.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 1.674
Times cited: 6
DOI: 10.1002/pssb.201248169
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“Functional Respiratory Imaging as a tool to personalize respiratory treatment in subjects with unilateral diaphragmatic paralysis”. Van Holsbeke CS, Leemans G, Vos WG, de Backer JW, Vinchurkar SC, Geldof M, Verdonck PR, Parizel PM, van Schil PE, de Backer WA, Respiratory care , 1 (2013). http://doi.org/10.4187/respcare.02756
Abstract: In two subjects with a unilateral diaphragmatic paralysis and complaints of dyspnea, a completely different treatment approach was chosen despite similar anatomical and physiological abnormalities. These decisions were supported by the results generated by Functional Respiratory Imaging (FRI). FRI was able to generate functional information with respect to lobar ventilation and local drug deposition. In one subject, it was found that some lobes were poorly ventilated and drug deposition simulation showed that some regions were undertreated. This subject underwent a diaphragm plication to restore the ventilation. In the other subject, it was found that all lobes were still ventilated. A conservative approach with regular follow-up was chosen to wait for spontaneous recovery of the diaphragmatic function. Both subjects improved subjectively and objectively. These cases demonstrate how novel medical imaging techniques such as FRI can be used to personalize respiratory treatment in subjects with unilateral diaphragmatic paralysis.
Keywords: A1 Journal article; Condensed Matter Theory (CMT); Antwerp Surgical Training, Anatomy and Research Centre (ASTARC); Laboratory Experimental Medicine and Pediatrics (LEMP)
Impact Factor: 1.733
Times cited: 5
DOI: 10.4187/respcare.02756
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“Aberration-corrected microscopy and spectroscopy analysis of pristine, nitrogen containing detonation nanodiamond”. Turner S, Shenderova O, da Pieve F, Lu Y-G, Yücelen E, Verbeeck J, Lamoen D, Van Tendeloo G, Physica status solidi : A : applications and materials science 210, 1976 (2013). http://doi.org/10.1002/pssa.201300315
Abstract: Aberration-corrected transmission electron microscopy, electron energy-loss spectroscopy, and density functional theory (DFT) calculations are used to solve several key questions about the surface structure, the particle morphology, and the distribution and nature of nitrogen impurities in detonation nanodiamond (DND) cleaned by a recently developed ozone treatment. All microscopy and spectroscopy measurements are performed at a lowered acceleration voltage (80/120kV), allowing prolonged and detailed experiments to be carried out while minimizing the risk of knock-on damage or surface graphitization of the nanodiamond. High-resolution TEM (HRTEM) demonstrates the stability of even the smallest nanodiamonds under electron illumination at low voltage and is used to image the surface structure of pristine DND. High resolution electron energy-loss spectroscopy (EELS) measurements on the fine structure of the carbon K-edge of nanodiamond demonstrate that the typical * pre-peak in fact consists of three sub-peaks that arise from the presence of, amongst others, minimal fullerene-like reconstructions at the nanoparticle surfaces and deviations from perfect sp(3) coordination at defects in the nanodiamonds. Spatially resolved EELS experiments evidence the presence of nitrogen within the core of DND particles. The nitrogen is present throughout the whole diamond core, and can be enriched at defect regions. By comparing the fine structure of the experimental nitrogen K-edge with calculated energy-loss near-edge structure (ELNES) spectra from DFT, the embedded nitrogen is most likely related to small amounts of single substitutional and/or A-center nitrogen, combined with larger nitrogen clusters.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 1.775
Times cited: 37
DOI: 10.1002/pssa.201300315
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“Towards CMOS-compatible single-walled carbon nanotube resonators”. Pathangi H, Cherman V, Khaled A, Sorée B, Groeseneken G, Witvrouw A, Microelectronic engineering 107, 219 (2013). http://doi.org/10.1016/j.mee.2012.06.007
Abstract: We report a totally CMOS-compatible fabrication technique to assemble horizontally suspended single-walled carbon nanotube (SWCNT) resonators. Individual SWCNTs are assembled in parallel at multiple sites by a technique called dielectrophoresis. The mechanical resonance frequencies of the suspended SWCNTs are in the range of 2035 MHz as determined from the piezoresistive response of the resonators during electrostatic actuation. The resistance of the suspended SWCNT either remains unchanged or increases or decreases significantly as a function of the actuation frequency. This can be explained by the effect the nanotube chirality has on the piezoresistive gauge factor.
Keywords: A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT)
Impact Factor: 1.806
Times cited: 6
DOI: 10.1016/j.mee.2012.06.007
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“Nanostructures in LuFe2O4+\delta”. Hervieu M, Damay F, Poienar M, Elkaim E, Rouquette J, Abakumov AM, Van Tendeloo G, Maignan A, Martin C, Solid state sciences 23, 26 (2013). http://doi.org/10.1016/j.solidstatesciences.2013.05.015
Abstract: A LuFe2O4+delta sample, previously characterized by X-ray synchrotron and neutron diffraction, has been studied by electron microscopy techniques, in order to get a precise description of its micro- and nanostructures at room temperature. The X-ray synchrotron data vs. temperature show that the monoclinic distortion is associated with the charge ordering; this distortion results in elongated twinning domains, which enhance the complexity of the microstructural state at room temperature. The structural modulation associated with oxygen excess is observed in large domains inside a non modulated matrix, in contrast with the modulations associated with the charge ordering of the Fe2+ and Fe3+ species, which are mostly short-range. The investigation of the nature and density of defects in the sample shows that they are nano-scaled, preserving the regularity of the layer stacking mode, and limited to the formation of one- or two-units large stacking faults, associated with gliding mechanisms. Based on these observations, an original description of the LuFe2O4 ferrite structure, through puckered [LuO4](infinity) sandwiching [Fe-2](infinity) layers, is proposed. (C) 2013 Elsevier Masson SAS. All rights reserved.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 1.811
Times cited: 7
DOI: 10.1016/j.solidstatesciences.2013.05.015
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“NEXAFS spectromicroscopy of suspended carbon nanohorns”. Bittencourt C, Ke X, Van Tendeloo G, Tagmatarchis N, Guttmann P, Chemical physics letters 587, 85 (2013). http://doi.org/10.1016/j.cplett.2013.09.034
Abstract: We demonstrate that near-edge X-ray-absorption fine-structure spectroscopy combined with full-field transmission X-ray microscopy can be used to study the electronic structure of suspended carbon nanohorns. Based on reports of electronic structure calculations additional spectral features observed in the π region of the NEXAFS spectrum recorded on the carbon nanohorns were associated to the presence of the pentagonal rings and the folding of the graphene sheet.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 1.815
Times cited: 4
DOI: 10.1016/j.cplett.2013.09.034
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“On the low-temperature growth mechanism of single walled carbon nanotubes in plasma enhanced chemical vapor deposition”. Shariat M, Shokri B, Neyts EC, Chemical physics letters 590, 131 (2013). http://doi.org/10.1016/j.cplett.2013.10.061
Abstract: Despite significant progress in single walled carbon nanotube (SWCNT) production by plasma enhanced chemical vapor deposition (PECVD), the growth mechanism in this method is not clearly understood. We employ reactive molecular dynamics simulations to investigate how plasma-based deposition allows growth at low temperature. We first investigate the SWCNT growth mechanism at low and high temperatures under conditions similar to thermal CVD and PECVD. We then show how ion bombardment during the nucleation stage increases the carbon solubility in the catalyst at low temperature. Finally, we demonstrate how moderate energy ions sputter amorphous carbon allowing for SWCNT growth at 500 K. (C) 2013 Elsevier B. V. All rights reserved.
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 1.815
Times cited: 14
DOI: 10.1016/j.cplett.2013.10.061
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“Platinum and palladium on carbon nanotubes : experimental and theoretical studies”. Adjizian JJ, De Marco P, Suarez-Martinez I, El Mel AA, Snyders R, Gengler RYN, Rudolf P, Ke X, Van Tendeloo G, Bittencourt C, Ewels CP;, Chemical physics letters 571, 44 (2013). http://doi.org/10.1016/j.cplett.2013.03.079
Abstract: Pristine and oxygen plasma functionalised carbon nanotubes (CNTs) were studied after the evaporation of Pt and Pd atoms. High resolution transmission electron microscopy shows the formation of metal nanoparticles at the CNT surface. Oxygen functional groups grafted by the plasma functionalization act as nucleation sites for metal nanoparticles. Analysis of the C1s core level spectra reveals that there is no covalent bonding between the Pt or Pd atoms and the CNT surface. Unlike other transition metals such as titanium and copper, neither Pd nor Pt show strong oxygen interaction or surface oxygen scavenging behaviour.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 1.815
Times cited: 23
DOI: 10.1016/j.cplett.2013.03.079
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“Stability of Ge12C48 and Ge20C40 heterofullerenes : a first principles molecular dynamics study”. Massobrio C, Djimbi DM, Matsubara M, Scipioni R, Boero M, Chemical physics letters 556, 163 (2013). http://doi.org/10.1016/j.cplett.2012.11.033
Abstract: By using first-principles molecular dynamics, we address the issue of structural stability for the C-60 Ge-m(m) family of doped heterofullerenes through a set of calculations targeting C48Ge12 and C40Ge20. Three kinds of theoretical tools are employed: (a) static structural optimization, (b) a bonding analysis based on localized orbitals (Wannier wavefunctions and centers) and (c) first-principles molecular dynamics at finite temperature. This latter tool allows concluding that the segregated form of C40Ge20 is less stable than its Si-based counterpart. However, the non-segregated forms of C40Ge20 and C40Si20 have comparable stabilities at finite temperatures. (C) 2012 Elsevier B. V. All rights reserved.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 1.815
Times cited: 3
DOI: 10.1016/j.cplett.2012.11.033
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“Effect of deposition rate on the microstructure of electron beam evaporated nanocrystalline palladium thin films”. Amin-Ahmadi B, Idrissi H, Galceran M, Colla MS, Raskin JP, Pardoen T, Godet S, Schryvers D, Thin solid films : an international journal on the science and technology of thin and thick films 539, 145 (2013). http://doi.org/10.1016/j.tsf.2013.05.083
Abstract: The influence of the deposition rate on the formation of growth twins in nanocrystalline Pd films deposited by electron beam evaporation is investigated using transmission electron microscopy. Statistical measurements prove that twin boundary (TB) density and volume fraction of grains containing twins increase with increasing deposition rate. A clear increase of the dislocation density was observed for the highest deposition rate of 5 Å/s, caused by the increase of the internal stress building up during deposition. Based on crystallographic orientation indexation using transmission electron microscopy, it can be concluded that a {111} crystallographic texture increases with increasing deposition rate even though the {101} crystallographic texture remains dominant. Most of the TBs are fully coherent without any residual dislocations. However, for the highest deposition rate (5 Å/s), the coherency of the TBs decreases significantly as a result of the interaction of lattice dislocations emitted during deposition with the growth TBs. The analysis of the grain boundary character of different Pd films shows that an increasing fraction of high angle grain boundaries with misorientation angles around 5565° leads to a higher potential for twin formation.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 1.879
Times cited: 13
DOI: 10.1016/j.tsf.2013.05.083
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“Annular dark-field transmission electron microscopy for low contrast materials”. Leroux F, Bladt E, Timmermans J-P, Van Tendeloo G, Bals S, Microscopy and microanalysis 19, 629 (2013). http://doi.org/10.1017/S1431927613000020
Abstract: Imaging soft matter by transmission electron microscopy (TEM) is anything but straightforward. Recently, interest has grown in developing alternative imaging modes that generate contrast without additional staining. Here, we present a dark-field TEM technique based on the use of an annular objective aperture. Our experiments demonstrate an increase in both contrast and signal-to-noise ratio in comparison to conventional bright-field TEM. The proposed technique is easy to implement and offers an alternative imaging mode to investigate soft matter.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 1.891
Times cited: 5
DOI: 10.1017/S1431927613000020
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