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| 3. |
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| 4. |
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| 5. |
- Richard, G., et al.
(författare)
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Multi Modal Verification for Teleservices and Security Applications (M2VTS)
- 1999
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Ingår i: IEEE International Conference on Multimedia Computing and Systems. - Los Alamitos : IEEE. - 0769502539 ; , s. 1061-1064
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- This paper presents the European ACTS project M2VTS which stands for Multi Modal Verification for Teleservices and Security Applications. The primary goal of this project is to address the issue of secured access to local and centralised services in a multimedia environment. The main objective is to extend the scope of application of network-based services by adding novel and intelligent functionalities, enabled by automatic verification systems combining multimodal strategies (secured access based on speech, image or other information). The objectives of the project are also to show that limitations of individual technologies (speaker verification, frontal face authentication, profile identification,...) can be overcome by relying on multi-modal decisions (combination or fusion of these technologies).
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| 6. |
- Antti, Marta-Lena, et al.
(författare)
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Synthesising of a model composite in the oxide/oxide system : alumina fibre reinforced alumina matrix
- 1999
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Ingår i: Advanced structural fiber composites. - : TECHNA Srl. - 8886538235
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Konferensbidrag (refereegranskat)abstract
- Ceramic matrix composites have attracted big interest as potential material for high temperature applications. To avoid one of the main problems, namely oxidation at higher temperatures, interest has increased for systems where both reinforcement and matrix material are ceramic oxides. This work presents a possible method of producing long fibre reinforced ceramic matrix composites. The method was applied to single crystal aluminium oxide fibres in a polycrystalline alumina matrix and involves cladding individual fibres with the matrix material in the form of pre-sintered tubes with appropriately small diameter. The composite is then hot isostatically pressed (HIP), by putting several fibre-tube pairs in a container of required diameter. A HIP cycle was found that led to full densification of the composite without visual damage to the fibres. The method produces composites with an ideal uniform fibre spacing; samples of cylindrical shape suitable, for example, for uniaxial testing can be produced
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| 7. |
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| 8. |
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| 9. |
- Minet, Ariane D., et al.
(författare)
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Teneurin-1, a vertebrate homologue of the Drosophila pair-rule gene ten-m, is a neuronal protein with a novel type of heparin-binding domain
- 1999
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Ingår i: Journal of Cell Science. - 0021-9533. ; 112:12, s. 2019-2032
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Tidskriftsartikel (refereegranskat)abstract
- The Drosophila gene ten-m is the first pair-rule gene not encoding a transcription factor, but an extracellular protein. We have characterized a highly conserved chicken homologue that we call teneurin-1. The C-terminal part harbors 26 repetitive sequence motifs termed YD-repeats. The YD-repeats are most similar to the core of the rhs elements of Escherichia coli. Related repeats in toxin A of Clostridium difficile are known to bind specific carbohydrates. We show that recombinantly expressed proteins containing the YD-repeats of teneurin-1 bind to heparin. Furthermore, heparin lyase treatment of extracts of cells expressing recombinant YD-repeat protein releases this protein from high molecular mass aggregates. In situ hybridization and immunostaining reveals teneurin-1 expression in neurons of the developing visual system of chicken and Drosophila. This phylogenetic conservation of neuronal expression from flies to birds implies fundamental roles for teneurin-1 in neurogenesis. This is supported by the neurite outgrowth occurring on substrates made of recombinant YD-repeat proteins, which can be inhibited by heparin. Database searches resulted in the identification of ESTs encoding at least three further members of the teneurin family of proteins. Furthermore, the human teneurin-1 gene could be identified on chromosome Xq24/25, a region implied in an X-linked mental retardation syndrome.
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| 10. |
- West, Jay B., et al.
(författare)
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Comparison and evaluation of retrospective intermodality image registration techniques
- 1997
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Ingår i: SPIE - The International Society for Optical Engineering. - : SPIE - International Society for Optical Engineering. ; , s. 332-347
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Konferensbidrag (refereegranskat)abstract
- All retrospective image registration methods have attached to them some intrinsic estimate of registration error. However, this estimate of accuracy may not always be a good indicator of the distance between actual and estimated positions of targets within the cranial cavity. This paper describes a project whose principal goal is to use a prospective method based on fiducial markers as a ’gold standard’ to perform an objective, blinded evaluation of the accuracy of several retrospective image-to-image registration techniques. Image volumes of three modalities – CT, MR, and PET – were taken of patients undergoing neurosurgery at Vanderbilt University Medical Center. These volumes had all traces of the fiducial markers removed, and were provided to project collaborators outside Vanderbilt, who then performed retrospective registrations on the volumes, calculating transformations from CT to MR and/or from PET to MR, and communicated their transformations to Vanderbilt where the accuracy of each registration was evaluated. In this evaluation the accuracy is measured at multiple ’regions of interest,’ i.e. areas in the brain which would commonly be areas of neurological interest. A region is defined in the MR image and its centroid C is determined. Then the prospective registration is used to obtain the corresponding point C’ in CT or PET. To this point the retrospective registration is then applied, producing C’ in MR. Statistics are gathered on the target registration error (TRE), which is the disparity between the original point C and its corresponding point C’. A second goal of the project is to evaluate the importance of correcting geometrical distortion in MR images, by comparing the retrospective TRE in the rectified images, i.e., those which have had the distortion correction applied, with that of the same images before rectification. This paper presents preliminary results of this study along with a brief description of each registration technique and an estimate of both preparation and execution time needed to perform the registration.
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| 11. |
- Aitken, Candice L., et al.
(författare)
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Comparison of three methods used for fusion of SPECT-CT images of liver matastases
- 1998
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Ingår i: Fusion98, International Conference on Multisource-Mulltisensor Information Fusion. - : CSREA Press. - 1892512009 ; , s. 435-442
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Konferensbidrag (refereegranskat)abstract
- We compare three methods for fusing SPECT-CT images: ImageMatch - an automatic three-dimensional/two-dimensional method developed by Focus Imaging; IBM Visualization Data Explorer - a three-diemensional interactive method developed by Internation Business Machines, Inc.; and qsh - an interactive three-dimensional/two-dimensional method developed at New York University. While many fusion methods have proved successful for registering brain images, most methods have been less successful for thoracic and abdominal images. We use images of liver metastases obtained with a radiolabeled breast tumor-directed antibody to illustrate the strengths and weakness of the methods reviewed. The images used are typical clinical images from eigth patients. We conclude that an optimal image fusion program should combine the strengths of each of the methods reviewed.
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| 12. |
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| 13. |
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| 14. |
- Fahey, Richard P, et al.
(författare)
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Perception of back vowels : effects of varying F1 - F0 Bark distance.
- 1996
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Ingår i: J Acoust Soc Am. - 0001-4966. ; 99:4 Pt 1, s. 2350-7
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Tidskriftsartikel (refereegranskat)abstract
- In a study of vowel height perception using front vowels, Hoemeke and Diehl [J. Acoust. Soc. Am. 96, 661 - 674 (1994)] found that F1 - F0 distance was the best predictor of perceived vowel height for the phonological distinction [+/-high], while for two other vowel height distinctions F1 alone was the best predictor. Further, the [+/-high] identification function was defined by a sharp boundary located at 3 to 3.5 Bark F1-F0 distance. One hypothesis offered was that F1 - F0 distance had cue value for the [+/-high] distinction because of an underlying quantal region on the F1 - F0 distance dimension. However, the results are also predicted if it is supposed that F1 - F0 distance is a cue for vowel height only for pure height distinctions. The present study further tested these possibilities, using back vowels. The results allowed us to reject both as general explanations of vowel height perception. However, the results were consistent with a third possible explanation, namely, that phonetic quality is determined by the tonotopic distances between any adjacent spectral peaks (e.g., F3 - F2, F2 - F1, and F1 - F0), with greater perceptual weight accorded to smaller distances.
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| 15. |
- Farrell, Edward J., et al.
(författare)
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Graphical 3D medical image registration and quantification
- 1997
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Ingår i: Journal of medical systems. - 0148-5598 .- 1573-689X. ; 21:3, s. 155-172
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Tidskriftsartikel (refereegranskat)abstract
- We present a graphical three-dimensional method that facilitates image registration and fusion, and provides quantitative geometric and volume information. In particular it enhances the use of functional (radiopharmaceutical) imaging {(SPECT}, {PET)} which, though a powerful clinical tool, has the disadvantage of low spatial resolution and ill-defined boundaries. Registration between functional images and structural images {(MRI}, {CT)} can augment the anatomical context of these functional images.
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| 16. |
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| 17. |
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| 18. |
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| 19. |
- Hultling, C, et al.
(författare)
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Assisted ejaculation and in-vitro fertilization in the treatment of infertile spinal cord-injured men : the role of intracytoplasmic sperm injection.
- 1997
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Ingår i: Human Reproduction. - : Oxford University Press. - 0268-1161 .- 1460-2350. ; 12:3, s. 499-502
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Tidskriftsartikel (refereegranskat)abstract
- The objective of the present longitudinal descriptive study was to extend previous observations on the benefit of in-vitro fertilization (IVF) in cases of anejaculatory infertility due to spinal cord injuries (SCI) and to report results achieved by intracytoplasmic sperm injection (ICSI). The study was performed in a national referral unit for SCI, Spinalis SCI Research Unit, the Karolinska Institute. The patient material consisted of couples with SCI men seeking treatment for their infertility. The inclusion criteria were: stable relationship, motile spermatozoa in a diagnostic sample and no female contraindications. Spermatozoa were retrieved through electroejaculation or vibratory stimulation. If the sperm quality was judged to be sufficient, standard IVF was performed. ICSI was employed if the semen quality was extremely poor. We have treated 25 couples in 52 cycles, leading to 81 ovum retrievals and 47 embryo transfers. Total sperm counts were very variable (0.01-978 x 10(6)). Before the introduction of ICSI the fertilization rate was 30%. ICSI increased the fertilization rate to 88%. There was no association between the pregnancy rate and the sperm count, level of injury or fertilization technique. A total of 16 clinical pregnancies was established, leading to 11 deliveries. This gives a cumulative pregnancy rate per couple of 56%.
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| 20. |
- Hultling, C, et al.
(författare)
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Assisted ejaculation combined with in vitro fertilisation : an effective technique treating male infertility due to spinal cord injury.
- 1994
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Ingår i: Paraplegia. - : Springer Science and Business Media LLC. - 0031-1758. ; 32:7, s. 463-467
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Tidskriftsartikel (refereegranskat)abstract
- Infertility due to spinal cord injury (SCI) in males has been identified for decades as an area of major concern and techniques for assisted ejaculation are available. There has not been an overall consensus regarding which type of assisted procreation is the most appropriate for these couples. We describe here our experience from a programme based on assisted ejaculation combined with in vitro fertilization (IVF). Twelve couples have been treated so far and altogether 22 cycles with ovum pick-up have been completed. Fertilisation of the oocytes was obtained in 18 of these cycles. The overall oocyte fertilisation rate was 49%. Embryo transfer took place in 17 cycles, leading to seven clinical pregnancies. Four of the pregnancies are delivered or are ongoing, whereas three ended in first trimester spontaneous abortion. Thus our initial experience suggests that assisted ejaculation in combination with IVF is an effective option for these couples.
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| 21. |
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| 22. |
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| 23. |
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| 24. |
- Leblanc, James P., et al.
(författare)
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Fractionally spaced CMA equalizers under periodic and correlated inputs
- 1995
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Ingår i: Conference proceedings ICASSP-95. - Piscataway, NJ : IEEE Communications Society. ; , s. 1041-1044
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Konferensbidrag (refereegranskat)abstract
- CMA fractionally spaced equalizers (CMA-FSEs) have been shown, under certain conditions, to be globally asymptotically convergent to a setting which provides perfect equalization. Such a result relies heavily on the assumptions of a white source and no channel noise (as is the case in much of the literature's analysis of CMA). Herein, we relax the white source assumption and examine the effect of source correlation on CMA. Analytic results are meshed with examples showing CMA-FSE source correlation effects. Techniques for finding all stationary and saddle points on the CMA-FSE error surface are presented using recent developments in the algebraic-geometry community.
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| 25. |
- Lorber, Christian, et al.
(författare)
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Synthesis, Structures and Oxo Transfer Reactivity of bis(Dithiolene) Tungsten(IV,VI) Complexes Related to the Active Sites of Tungstoenzymes
- 1998
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Ingår i: Journal of the American Chemical Society. - : American Chemical Society (ACS). - 1520-5126 .- 0002-7863. ; 120:32, s. 8102-8112
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Tidskriftsartikel (refereegranskat)abstract
- A series of bis(dithiolene)tungsten(IV,VI) complexes derived from benzene-1,2-dithiolate (bdt) has been prepared as an synthetic approach to pterin dithiolene-bound active sites of tungstoenzymes, one example of which, a archaeal oxidoreductase, has been established crystallographically (Chan et al. Science 1995, 267, 1463). With [WIVO(bdt)2]2- (2) as the starting compound, silylation with RR'2SiCl afforded [WIV(bdt)2(OSiRR'2)]1- (4). Oxidation of 4 with Me3NO gave [WVIO(bdt)2(OSiRR'2)]1- (5), also accessible by silylation of [WVIO2(bdt)2]2- (3). Reaction of 3 or 5 with Me3SiCl resulted in [WVIO(bdt)2Cl]1- (6), from which the unstable species [WVIO(bdt)2L]1- (L = ButO-, PhS-) were generated in solution. Reductive oxo transfer of 6 with L' = P(OEt)3 or ButNC/P(OEt)3 gave [WIV(bdt)2L'2] (8 and 9). Sulfido complex [WVIS(bdt)2(OSiRR'2)]1- (12) was obtained in the reaction systems 4/(PhCH2S)2S and 5/(Me3Si)2S. Structures of [WO(SPh)4]1- and [W(bdt)3]2- and eight complexes of types 4-6, 8, 9, and 12 were determined by X-ray crystallography. Complexes 4 and 5 are tungsten analogues of the desoxo Mo(IV) and monooxo Mo(VI) states of Rhodobacter sphaeroides DMSO reductase. Six types of reactivity, including oxygen atom transfer, are recognized by the synthesis and interconversion of the set of complexes. The potential biological relevance of these complexes to the structure and function of active sites in two families of tungstoenzymes is considered (RR'2 = Me3 (4); ButMe2 (4 and 5), ButPh2 (4, 5, and 12)).
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| 26. |
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| 27. |
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| 28. |
- Morthier, G., et al.
(författare)
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Extraction of a large set of laser parameters from different measurements
- 1996
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Ingår i: Semiconductor Laser Conference, 1996., 15th IEEE International. ; , s. 175-176
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Konferensbidrag (refereegranskat)abstract
- We show how most of the parameters of a DFB laser can be extracted from a limited number of relatively simple measurements. These measurements include the ASE spectra at different currents below threshold, the RIN spectra above threshold and the P-I relation. We have performed curve-fitting on different characteristics such as the ASE spectrum, the RIN spectrum and the P-I curve. From the ASE spectrum measured in the vicinity of the lasing wavelength we can extract grating parameters, facet phases, refractive index and gain as well as the wavelength and current dependence of the last two parameters
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| 29. |
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| 30. |
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| 31. |
- Rigole, P. J., et al.
(författare)
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Modulation and noise measurements from 1520 to 1560 nm in monolithic widely tunable semiconductor lasers
- 1998
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Ingår i: Lasers and Electro-Optics, 1998. CLEO 98. Technical Digest. Summaries of papers presented at the Conference on. ; , s. 303-304
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Konferensbidrag (refereegranskat)abstract
- Widely tunable semiconductor lasers have a large number of applications. We believe we report for the first time measurements of intensity modulation response, frequency, and intensity noise characteristics of a grating-assisted co-directional coupler with rear sampled grating reflector (GCSR) lasers
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| 32. |
- Saavedra, A. A., et al.
(författare)
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Amplitude and frequency modulation characteristics of widely tunable GCSR lasers
- 1998
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Ingår i: IEEE Photonics Technology Letters. - : Institute of Electrical and Electronics Engineers (IEEE). - 1041-1135 .- 1941-0174. ; 10, s. 1383-1385
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Tidskriftsartikel (refereegranskat)abstract
- The amplitude (AM) and frequency (FM) modulation responses of a grating assisted codirectional coupler with rear sampled grating reflector laser were measured over a 40-nm tuning range. The extracted modulation bandwidth varied between 3 and 4 GHz and parameters as parasitic cutoff, maximum relaxation frequency and K-factor were extracted from curve fittings to the AM response. The frequency modulation measurements revealed low chirp despite the large tunability of the device. The linewidth enhancement factor was calculated from the AM and FM measurements. The values ranges from three to nine for ten different operating wavelengths
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| 33. |
- Saavedra, A. A., et al.
(författare)
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Measurement of amplitude and frequency modulation responses of widely tunable GCSR lasers
- 1998
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Ingår i: Semiconductor Laser Conference, 1998. ISLC 1998 NARA. 1998 IEEE 16th International. ; , s. 179-180
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Konferensbidrag (refereegranskat)abstract
- The amplitude and frequency modulation responses of a grating assisted codirectional coupler (GCSR) semiconductor laser were measured over 40 nm tuning range. The extracted modulation bandwidth varied between 3 and 4 GHz and the linewidth enhancement factors range from 3 to 9
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| 34. |
- Saavedra, A. A., et al.
(författare)
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Relative intensity noise and linewidth measurements of a widely tunable GCSR laser
- 1998
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Ingår i: IEEE Photonics Technology Letters. - : Institute of Electrical and Electronics Engineers (IEEE). - 1041-1135 .- 1941-0174. ; 10, s. 481-483
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Tidskriftsartikel (refereegranskat)abstract
- The intensity and frequency noise of a grating assisted codirectional coupler with rear sampled grating reflector laser with 40-nm tuning range and 35-dB sidemode suppression ratio (SMSR) have been measured. The linewidth varies from 430 kHz to 4 MHz as a function of tuning. The resonance frequency, intrinsic bandwidth and damping factor for this device were extracted from the relative intensity noise (RIN) measurements. At high bias, the RIN is -150 dB/Hz and the maximum resonance frequency is 4.5 GHz
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| 35. |
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| 36. |
- Skagerlund, J., et al.
(författare)
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Evaluation of an automatic method to extract the grating coupling coefficient in different types of fabricated DFB lasers
- 1998
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Ingår i: IEEE Journal of Quantum Electronics. - : Institute of Electrical and Electronics Engineers (IEEE). - 0018-9197 .- 1558-1713. ; 34, s. 141-146
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Tidskriftsartikel (refereegranskat)abstract
- Distributed feedback (DFB) laser parameters such as grating coupling coefficient, effective indices, facet reflectances, and the phases of facet reflectances have been determined using a method based on least-square fitting of theoretical spectra to measured, subthreshold DFB laser emission spectra. The only inputs needed are geometrical parameters such as length, grating period, and internal grating phase shifts. A larger number of devices have been successfully characterized, and consistent results have been obtained in both 1.3- mu;m multi-quantum-well (MQW) DFB lasers with both facets as-cleaved, and in 1.55- mu;m MQW DFB lasers with no, one, or two facets as-cleaved
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| 37. |
- Thapper, Anders, et al.
(författare)
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The Unperturbed Oxo-Sulfido Functional Group cis-Mo(VI)OS, Related to that in the Xanthine Oxidase Family of Molybdoenzymes: Synthesis, Structural Characterization and Reactivity Aspects
- 1999
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Ingår i: Inorganic Chemistry. - : American Chemical Society (ACS). - 1520-510X .- 0020-1669. ; 38:18, s. 4104-4114
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Tidskriftsartikel (refereegranskat)abstract
- The oxo-sulfido functional group cis-MoVIOS is essential to the activity of the xanthine oxidase family of enzymes but has proven elusive to synthesis in molecules containing no other four-electron ligands. A direct route to molecules containing this group has been achieved. The reaction system [MoO2(OSiPh3)2]/L in dichloromethane yields the complexes [MoVIO2(OSiPh3)2L] (L = phen (1), Me4phen (2), 4,4'-Me2bpy (3), 5,5'-Me2bpy (4), 2 py (5)) (74-96%), which are shown to have a distorted octahedral structure of crystallographically imposed C2 symmetry (1, 5) with cis oxo and trans silyloxy ligands. The related reaction system [MoO3S]2-/2Ph3SiCl/L in acetonitrile affords the complexes [MoVIOS(OSiPh3)2L] (L = phen (6), Me4phen (7), 4,4'-Me2bpy (8), 5,5'-Me2bpy (9)) (36-69%). From the collective results of elemental analysis, mass spectrometry, 1H NMR, and X-ray structure determinations (6, 7), complexes 6-9 are shown to contain the cis-MoVIOS group in molecules with the same overall stereochemistry as dioxo complexes 1-5. The crystal structures of 6 and 7 exhibit O/S disorder, which was modeled in refinements with 50% site occupancies. The Mo=O (1.607(5) (6), 1.645(5) (7) Å) and Mo=S (2.257(3) (6), 2.203(2) (7) Å) bond distances obtained in this way are somewhat shorter and longer, respectively, than expected. Distances obtained by molybdenum EXAFS analysis using the GNXAS protocol for 6-9 (Mo=O 1.71-1.72 Å; Mo=S 2.18-2.19 Å) are considered more satisfactory and are in good agreement with EXAFS values for xanthine oxidase. Molybdenum K-edge data for 1 and 6-9 are reported. Reaction of 7 with Ph3P in dichloromethane results in sulfur abstraction and formation of [MoVOCl(OSiPh3)2(Me4phen)] (10), which has a distorted octahedral structure with cis O/Cl and cis silyloxy ligands. Sulfur rather than oxygen abstraction is favored by relative Mo=O/Mo=S bond strengths. Complexes 6-9 should allow exploration of the biologically significant cis-MoVIOS group.
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| 38. |
- Timms, Kirsten M, et al.
(författare)
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Molecular and phenotypic variation in patients with severe Hunter syndrome
- 1997
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Ingår i: Human Molecular Genetics. - : Oxford University Press (OUP). - 0964-6906 .- 1460-2083. ; 6:3, s. 479-486
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Tidskriftsartikel (refereegranskat)abstract
- Severe Hunter syndrome is a fatal X-linked lysosomal storage disorder caused by iduronate-2-sulphatase (IDS) deficiency. Patients with complete deletion of the IDS locus often have atypical phenotypes including ptosis, obstructive sleep apnoea, and the occurrence of seizures. We have used genomic DNA sequencing to identify several new genes in the IDS region. DNA deletion patients with atypical symptoms have been analysed to determine whether these atypical symptoms could be due to involvement of these other loci. The occurrence of seizures in two individuals correlated with a deletion extending proximal of IDS, up to and including part of the FMR2 locus. Other (non-seizure) symptoms were associated with distal deletions. In addition, a group of patients with no variant symptoms, and a characteristic rearrangement involving a recombination between the IDS gene and an adjacent IDS pseudogene (IDS psi), showed normal expression of loci distal to IDS. Together, these results identify FMR2 as a candidate gene for seizures, when mutated along with IDS.
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| 39. |
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| 40. |
- Vomacka, P., et al.
(författare)
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Zirconia as a nucleating agent in a yttria-alumina-silica glass
- 1995
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Ingår i: Journal of the European Ceramic Society. - 0955-2219 .- 1873-619X. ; 15:11, s. 1111-1117
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Tidskriftsartikel (refereegranskat)abstract
- The crystallization behaviour of a ZrO2-containing glass and a ZrO2-free glass in the Y2O3-Al2O3-SiO2 system prepared at 1700°C were compared in order to study the influence of ZrO2 on the nucleation and growth processes. Techniques used included SEM, DTA and XRD analysis. The microstructural development of the ZrO2-containing material during crystallization was more complex than that of the ZrO2-free material. In the crystallization treatments no phase separation prior to crystallization could be observed and no precursor crystalline phase was observed to form in the ZrO2-containing glass. Thus the added zirconia could be considered to act as a growth modifier rather than a catalyst nucleating agent.
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| 41. |
- Wei, L.-Y., et al.
(författare)
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The role of TEM in the development of materials in the automotive industry
- 1997
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Ingår i: 30th International Symposium on Automotive Technology and Automation, Florence, Italy, 16th - 19th June 1997. - : Automotive automation. - 0947719946 ; , s. 349-356
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Konferensbidrag (refereegranskat)abstract
- The aim of the present article is to highlight two examples of the unique role that transmission electron microscopy (TEM) can play to solve complex materials problems. The strength and fatigue resistance of cast Al alloys can be increased by adding copper and magnesium. TEM work revealed that a cylinder head alloy (Al-8Si-3Cu-0.3Mg) was effectively age-hardened by the formation of finely dispersed precipitates of ϑ" (CuAl2) and β" (Mg2Si) phases. The two precipitates were distinguished by the TEM. The geometry, the orientation, the shape and the size, etc., of the precipitates were completely characterized. A new type of precipitate containing Mn, Si, Cu and Al and finely dispersed in the matrix was discovered in this work. The second example is a TEM/STEM study of a grey iron. Alloying additions of, for example, Mo and Cu in the grey iron have a considerable effect in the strengthening of the alloy. It was found that Mo toughened the ferrite/Fe3C interface by forming a multi-layer structure on the surface of the cementite, and the ferrite matrix was strengthened by solution of Cu in the solid state and by a fine dispersion of coherent precipitates
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| 42. |
- Wenning, Gregor K, et al.
(författare)
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Short- and long-term survival and function of unilateral intrastriatal dopaminergic grafts in Parkinson's disease
- 1997
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Ingår i: Annals of Neurology. - : Wiley. - 1531-8249 .- 0364-5134. ; 42:1, s. 95-107
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Tidskriftsartikel (refereegranskat)abstract
- Six patients with Parkinson's disease were followed for 10 to 72 months after human embryonic mesencephalic tissue from four to seven donors was grafted unilaterally into the putamen (4 patients) or putamen plus caudate (2 patients). After 8 to 12 months, positron emission tomography showed a 68% increase of 6-L-[18F]-fluorodopa uptake in the grafted putamen, no change in the grafted caudate, and minor decreases in nongrafted striatal regions. There was therapeutically valuable improvement in 4 patients, but only modest changes in the other 2, both of whom developed atypical features. Patient 4 was without L-dopa from 32 months and had normal fluorodopa uptake in the grafted putamen at 72 months. Overall, the L-dopa dose was reduced by a mean of 10 and 20%, "off" time was reduced by 34 and 44%, and the "off" phase Unified Parkinson's Disease Rating Scale motor score by 18 and 26%, and the duration of the response to a single L-dopa dose increased by 45 and 58% during the first and second years after surgery, respectively. Rigidity and hypokinesia improved bilaterally, but mainly contralateral to the implant. No consistent changes in dyskinesias were observed. We conclude that transplantation of embryonic mesencephalic tissue leads to highly reproducible survival of dopaminergic neurons, inducing clinically valuable improvements in most recipients.
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