| 71. |
- Fernandes, CP, et al.
(författare)
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Reflection photoelasticity: a new method for studies of clinical mechanics in prosthetic dentistry
- 2003
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Ingår i: Dental Materials. - 0109-5641 .- 1879-0097. ; 19:2, s. 106-117
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Tidskriftsartikel (refereegranskat)abstract
- Objectives. This research was conducted to demonstrate the effectiveness of reflective photoelasticity as an in vivo technique for monitoring the strain/stress distribution in prosthetic devices during function. Methods. Seven subjects were selected for this study and divided into three groups according to the design of the prostheses. The buccal surfaces of the experimental prostheses were coated with a birefringent resin 2 mm thick. Using a reflection polariscope, fringe patterns were documented on video tape during standardized in vivo loadings. Strain and stress levels (gamma(max) and tau(max)) were calculated from isochromatic fringe order determinations. The intra-observer variability in counting fringe orders and the accuracy level of reflective photoelasticity as compared to strain gauge results were also studied. The strain results of in vivo loading of the prostheses were analyzed with ANOVA and Scheffes tests. The intra-observer variability was analyzed with the Friedman nonparametric test. Comparisons of photoelastic data and strain gauges were tested with Pearson's correlation. Results. Coated areas accessible to normally incident light, produced comprehensive maps of strain distribution. Significant differences were found in the in vivo gamma(max) values for the prostheses designs (p < 0.05). The test for intra-observer variability showed that no significant differences occurred in counting fringe orders. Strain values obtained with reflective photoelasticity showed a high correlation r = 0.98 and 0.99) with values obtained at the same areas using strain gauges. Significance. Reflective photoelasticity is a valid, reliable and accurate technique to be used for in vivo studies on the biomechanical behavior of prosthetic devices. (C) 2003 Academy of Dental Materials. Published by Elsevier Science Ltd. All rights reserved.
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| 72. |
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| 73. |
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| 74. |
- Ge, Yu, 1995, et al.
(författare)
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Experimental Validation of Single Base Station 5G mm Wave Positioning: Initial Findings
- 2022
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Ingår i: 2022 25th International Conference on Information Fusion, FUSION 2022. - Piscataway : IEEE.
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Konferensbidrag (refereegranskat)abstract
- 5G cellular networks can utilize millimeter wave signals, and support large bandwidths and large antenna arrays, which provide more geometric-based signals and higher delay and angle resolutions. These merits bring new opportunities in positioning the user with limited infrastructure through the use of combined angle and delay information. However, there are many practical challenges to overcome, in order to have a functioning single base station 5G mmWave positioning system. In this paper, we describe a deployed single base station mmWave positioning system, and provide an example of the measurement data. Furthermore, we perform measurement validation on a limited measurement data set by performing base station localization. Additional evaluations performed on simulation model data provide guidelines on the required size of the data set and receiver antenna configuration, which will be implemented in upcoming measurements.
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| 75. |
- Gillen, Michael, et al.
(författare)
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Effect of a spacer on total systemic and lung bioavailability in healthy volunteers and in vitro performance of the Symbicort® (budesonide/formoterol) pressurized metered dose inhaler
- 2018
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Ingår i: Pulmonary Pharmacology and Therapeutics. - : Elsevier BV. - 1094-5539 .- 1522-9629. ; 52, s. 7-17
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: Many patients with chronic obstructive pulmonary disease or asthma experience difficulties in coordinating inhalation with pressurized metered-dose inhaler (pMDI) actuation. The use of a spacer device can improve drug delivery in these patients. The aim of this study was to establish the relative bioavailability of single doses of Symbicort® (budesonide/formoterol) pMDI 160/4.5 μg/actuation (2 actuations) used with and without a spacer device. In addition, an in vitro study was conducted to characterize performance of the inhaler when used in conjunction with a spacer device. Methods: A Phase I, randomized, open-label, single-dose, single-center, crossover study in 50 healthy volunteers (NCT02934607) assessed the relative bioavailability of single-dose Symbicort® pMDI 160/4.5 μg/actuation (2 actuations) with and without a spacer (AeroChamber Plus® Flow-Vu®). Inhaled doses were administered without or with activated charcoal (taken orally) to estimate total systemic exposure and exposure through the lung, respectively. The in vitro study characterized the effect of the spacer with respect to delivered dose, fine particle dose, and dose during simulated breathing of budesonide and formoterol. Results: In terms of total systemic exposure, use of the spacer increased the relative bioavailability determined by AUC(0-last) and Cmax by 68% (spacer:no spacer treatment ratio, 167.9%; 90% CI, 144.1 to 195.6) and 99% (ratio, 198.7%; 90% CI, 164.4 to 240.2) for budesonide, and 77% (ratio, 176.6%; 90% CI, 145.1 to 215.0) and 124% (ratio, 223.6%; 90% CI, 189.9 to 263.3) for formoterol, respectively, compared with pMDI alone. Similarly, the lung exposure of budesonide and formoterol increased (AUC(0-last) and Cmax by 146% [ratio, 246.0%; 90% CI, 200.7 to 301.6] and 127% [ratio, 226.5%; 90% CI, 186.4 to 275.4] for budesonide, and 173% [ratio, 272.8%; 90% CI, 202.5 to 367.4] and 136% [ratio, 236.2%; 90% CI, 192.6 to 289.6] for formoterol, respectively) when the pMDI was administered through the spacer. When assessed by AUC(0-last) quartile without spacer, subjects in the lowest exposure quartile (indicating poor inhalation technique) with Symbicort® pMDI 160/4.5 μg/actuation (2 actuations) had markedly increased total systemic and lung exposure when the same dose was administered with the spacer. In contrast, for subjects in the highest exposure quartile with pMDI alone, total systemic and lung exposure of formoterol and budesonide was similar with and without the spacer. In the in vitro study, the fine particle dose (<5 μm) of both budesonide and formoterol from the spacer at delay time (i.e. pause period after actuation) = 0 s (instantaneous) after actuation was similar to the fine particle dose when not using the spacer. The delivered doses of budesonide and formoterol from the spacer were both lower compared with the doses administered without the spacer. There was also a decrease in delivered dose with increasing delay time. Conclusions: The clinical study demonstrated that in subjects with poor inhalation technique the use of the AeroChamber Plus® Flow-Vu® spacer increased the bioavailability of Symbicort® pMDI to a level observed in subjects with good inhalation technique without a spacer. The findings from the in vitro study support the fine particle dose characteristics of Symbicort® pMDI with the AeroChamber Plus® Flow-Vu® spacer.
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| 76. |
- Golpayegani, Ardeshir, 1975, et al.
(författare)
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Microstructure of a Creep-Resistant 10 Pct Chromium Steel Containing 250 ppm Boron
- 2011
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Ingår i: Metallurgical and Materials Transactions A: Physical Metallurgy and Materials Science. - : Springer Science and Business Media LLC. - 1073-5623 .- 1543-1940. ; 42:4, s. 940-951
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Tidskriftsartikel (refereegranskat)abstract
- The microstructure of a trial martensitic chromium steel containing a high content of boron (250 ppm) was characterized in detail in the as-tempered and aged conditions. This steel has a similar composition and heat treatment as the TAF steel that still is unsurpassed in creep strength among all 9 to 12 pct chromium steels. Characterization was performed by using scanning electron microscopy, energy-filtered transmission electron microscopy, secondary ion mass spectroscopy, and atom probe tomography. Focus was placed on investigating different types of precipitates that play a key role in improving the creep resistance of these steels. The low tempering temperature of 963 K (690 A degrees C) is enough for the precipitation of the full volume fraction of both MX and M23C6. A high boron content, more than 1 at. pct, was found in M23C6 precipitates and they grow slowly during aging. The high boron level in the steel results in metal borides rather than BN with the approximate formula (Mo0.66Cr0.34)(2)(Fe0.75V0.25)B-2. Two families of MX precipitates were found, one at lath boundaries about 35 nm in size and one dense inside the laths, only 5 to 15 nm in size.
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| 77. |
- Granroth, Sari, et al.
(författare)
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Investigation of interface properties of Ni/Cu multilayers by high kinetic energy photoelectron spectroscopy
- 2009
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Ingår i: Physical Review B (Condensed Matter and Materials Physics). - 1098-0121 .- 1550-235X. ; 80:9
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Tidskriftsartikel (refereegranskat)abstract
- High kinetic-energy photoelectron spectroscopy (HIKE) or hard x-ray photoelectron spectroscopy has been used to investigate the alloying of Ni/Cu (100) multilayers. Relative intensities of the corelevels and their chemical shifts derived from binding energy changes are shown to give precise information on physicochemical properties and quality of the buried layers. Interface roughening, including kinetic properties such as the rate of alloying, and temperature effects on the processes can be analyzed quantitatively. Using HIKE, we have been able to precisely follow the deterioration of the multilayer structure at the atomic scale and observe the diffusion of the capping layer into the multilayer structure which in turn is found to lead to a segregation in the ternary system. This is of great importance for future research on multilayered systems of this kind. Our experimental data are supplemented by first-principles theoretical calculations of the core-level shifts for a ternary alloy to allow for modeling of the influence of capping materials on the chemical shifts.
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| 78. |
- Granroth, Sari, et al.
(författare)
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Understanding interface properties from high kinetic energy photoelectron spectroscopy and first principles theory
- 2011
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Ingår i: Journal of Electron Spectroscopy and Related Phenomena. - : Elsevier BV. - 0368-2048 .- 1873-2526. ; 183:1-3, s. 80-93
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Forskningsöversikt (refereegranskat)abstract
- Advances in instrumentation regarding 3rd generation synchrotron light sources and electron spectrometers has enabled the field of high kinetic energy photoelectron spectroscopy (HIKE) (also often denoted hard X-ray photoelectron spectroscopy (HX-PES or HAXPES)). Over the last years, the amount of investigations that relies on the HIKE method has increased dramatically and can arguably be said to have given a rebirth of the interest in photoelectron spectroscopy in many areas. It is in particular the much increased mean free path at higher kinetic energies in combination with the elemental selectivity of the core level spectroscopies in general that has lead to this fact, as it makes it possible to investigate the electronic structure of materials with a substantially reduced surface sensitivity. In this review we demonstrate how HIKE can be used to investigate the interface properties in multilayer systems. Relative intensities of the core level photoelectron peaks and their chemical shifts derived from binding energy changes are found to give precise information on physico-chemical properties and quality of the buried layers. Interface roughening, including kinetic properties such as the rate of alloying, and temperature effects on the processes can be analyzed quantitatively. We will also provide an outline of the theoretical framework that is used to support the interpretation of data. We provide examples from our own investigations of multilayer systems which comprises both systems of more model character and a multilayer system very close to real applications in devices that are considered to be viable alternative to the present read head technology. The experimental data presented in this review is exclusively recorded at the BESSY-II synchrotron at the Helmholtz-Zentrum Berlin fur-Materialien und Energie. This HIKE facility is placed at the bending magnet beamline KMC-1, which makes it different from several other facilities which relies on undulators as the source. We will therefore also briefly describe some of the salient design features of this facility.
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| 79. |
- Grayson, Samuel, et al.
(författare)
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Blood flow dynamics in reconstructed auricles
- 2013
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Ingår i: Journal of Plastic Surgery and Hand Surgery. - 2000-656X. ; 47:4, s. 313-316
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Tidskriftsartikel (refereegranskat)abstract
- Ear reconstruction with autologous rib cartilage is performed in stages. Restitution of blood flow between the separate stages is crucial to obtain a good result. Laser Doppler perfusion imaging (LDPI) and local temperature were measured in reconstructed and normal ears in response to indirect heating. Ten persons who had had a unilateral ear reconstruction were included in the study. At a minimum, 157 days had passed since the last operation. LDPI showed no difference in blood flow between the reconstructed ear and the normal ear, neither before nor after indirect heating. The upper part of the normal ear was slightly cooler than the corresponding part in the reconstructed ear. Indirect heating caused an increase of LDPI-values and temperatures in the upper, middle, and lower part of the ear both in the reconstructed ear and the normal one. Skin blood flow recovers after 3-stage ear reconstruction and shows normal dynamic response upon indirect heating.
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| 80. |
- Grossi, Mario, et al.
(författare)
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Pyk2 inhibition promotes contractile differentiation in arterial smooth muscle
- 2017
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Ingår i: Journal of Cellular Physiology. - : Wiley. - 0021-9541. ; 232:11, s. 3088-3102
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Tidskriftsartikel (refereegranskat)abstract
- Modulation from contractile to synthetic phenotype of vascular smooth muscle cells is a central process in disorders involving compromised integrity of the vascular wall. Phenotype modulation has been shown to include transition from voltage-dependent toward voltage-independent regulation of the intracellular calcium level, and inhibition of non-voltage dependent calcium influx contributes to maintenance of the contractile phenotype. One possible mediator of calcium-dependent signaling is the FAK-family non-receptor protein kinase Pyk2, which is activated by a number of stimuli in a calcium-dependent manner. We used the Pyk2 inhibitor PF-4594755 and Pyk2 siRNA to investigate the role of Pyk2 in phenotype modulation in rat carotid artery smooth muscle cells and in cultured intact arteries. Pyk2 inhibition promoted the expression of smooth muscle markers at the mRNA and protein levels under stimulation by FBS or PDGF-BB and counteracted phenotype shift in cultured intact carotid arteries and balloon injury ex vivo. During long-term (24–96 hr) treatment with PF-4594755, smooth muscle markers increased before cell proliferation was inhibited, correlating with decreased KLF4 expression and differing from effects of MEK inhibition. The Pyk2 inhibitor reduced Orai1 and preserved SERCA2a expression in carotid artery segments in organ culture, and eliminated the inhibitory effect of PDGF stimulation on L-type calcium channel and large-conductance calcium-activated potassium channel expression in carotid cells. Basal intracellular calcium level, calcium wave activity, and store-operated calcium influx were reduced after Pyk2 inhibition of growth-stimulated cells. Pyk2 inhibition may provide an interesting approach for preserving vascular smooth muscle differentiation under pathophysiological conditions.
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