| 1. |
- Anand, K J S, et al.
(författare)
-
Effects of morphine analgesia in ventilated preterm neonates : primary outcomes from the NEOPAIN randomised trial
- 2004
-
Ingår i: The Lancet. - 0140-6736 .- 1474-547X. ; 363:9422, s. 1673-82
-
Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Opioid analgesia is commonly used during neonatal intensive care. We undertook the Neurologic Outcomes and Pre-emptive Analgesia in Neonates (NEOPAIN) trial to investigate whether pre-emptive morphine analgesia decreases the rate of a composite primary outcome of neonatal death, severe intraventricular haemorrhage (IVH), and periventricular leucomalacia (PVL) in preterm neonates.METHODS: Ventilated preterm neonates (n=898) from 16 centres were randomly assigned masked placebo (n=449) or morphine (n=449) infusions. After a loading dose (100 microg/kg), morphine infusions (23-26 weeks of gestation 10 microg kg(-1) h(-1); 27-29 weeks 20 microg kg(-1) h(-1); 30-32 weeks 30 microg kg(-1) h(-1)) were continued as long as clinically justified (maximum 14 days). Open-label morphine could be given on clinical judgment (placebo group 242/443 [54.6%], morphine group 202/446 [45.3%]). Analyses were by intention to treat.FINDINGS: Baseline variables were similar in the randomised groups. The placebo and morphine groups had similar rates of the composite outcome (105/408 [26%] vs 115/419 [27%]), neonatal death (47/449 [11%] vs 58/449 [13%]), severe IVH (46/429 [11%] vs 55/411 [13%]), and PVL (34/367 [9%] vs 27/367 [7%]). For neonates who were not given open-label morphine, rates of the composite outcome (53/225 [24%] vs 27/179 [15%], p=0.0338) and severe IVH (19/219 [9%] vs 6/189 [3%], p=0.0209) were higher in the morphine group than the placebo group. Placebo-group neonates receiving open-label morphine had worse rates of the composite outcome than those not receiving open-label morphine (78/228 [34%] vs 27/179 [15%], p<0.0001). Morphine-group neonates receiving open-label morphine were more likely to develop severe IVH (36/190 [19%] vs 19/219 [9%], p=0.0024).INTERPRETATION: Pre-emptive morphine infusions did not reduce the frequency of severe IVH, PVL, or death in ventilated preterm neonates, but intermittent boluses of open-label morphine were associated with an increased rate of the composite outcome. The morphine doses used in this study decrease clinical signs of pain but can cause significant adverse effects in ventilated preterm neonates.
|
|
| 2. |
- Andréasson, Sten, et al.
(författare)
-
Clinical studies of X-linked retinitis pigmentosa in three Swedish families with newly identified mutations in the RP2 and RPGR-ORF15 genes
- 2003
-
Ingår i: Ophthalmic Genetics. - : Swets & Zeitlinger Publishers. - 1381-6810 .- 1744-5094. ; 24:4, s. 215-223
-
Tidskriftsartikel (refereegranskat)abstract
- Purpose: To describe new disease-causing RP2 and RPGR-ORF15 mutations and their corresponding clinical phenotypes in Swedish families with X-linked retinitis pigmentosa (XLRP) and to establish genotype-phenotype correlations by studying the clinical spectrum of disease in families with a known molecular defect. Methods: Seventeen unrelated families with RP and an apparent X-linked pattern of disease inheritance were identified from the Swedish RP registry and screened for mutations in the RP2 and RPGR (for the RP3 disease) genes. These families had been previously screened for the RPGR exons 1-19, and disease-causing mutations were identified in four of them. In the remaining 13 families, we sequenced the RP2 gene and the newly discovered RPGR-ORF exon. Detailed clinical evaluations were then obtained from individuals in the three families with identified mutations. Results: Mutations in RP2 and RPGR-ORF15 were identified in three of the 13 families. Clinical evaluations of affected males and carrier females demonstrated varying degrees of retinal dysfunction and visual handicap, with early onset and severe disease in the families with mutations in the ORF15 exon of the RPGR gene. Conclusions: A total of seven mutations in the RP2 and RPGR genes have been discovered so far in Swedish XLRP families. All affected individuals express a severe form of retinal degeneration with visual handicap early in life, although the degree of retinal dysfunction varies both in hemizygous male patients and in heterozygous carrier females. Retinal disease phenotypes in patients with mutations in the RPGR-ORF15 were more severe than in patients with mutations in RP2 or other regions of the RPGR.
|
|
| 3. |
- Douheret, Oliver, et al.
(författare)
-
Characterization of quantum wells by cross-sectional Kelvin probe force microscopy
- 2004
-
Ingår i: Applied Physics Letters. - : AIP Publishing. - 0003-6951 .- 1077-3118. ; 85:22, s. 5245-5247
-
Tidskriftsartikel (refereegranskat)abstract
- Cross-sectional Kelvin probe force microscopy (KPFM) in ultrahigh vacuum is used to characterize the electronic structure of InGaAs/InP quantum wells. The KPFM signal shows clear peaks at the position of the quantum wells and exhibits a systematic trend for different wells. It is demonstrated that KPFM is capable of detecting quantum wells as narrow as 5 nm. Evidence for carrier accumulation in the quantum wells is observed. A complete quantitative analysis of the quantum well properties is shown to be impeded by tip averaging effects and due to surface/interface states.
|
|
| 4. |
|
|
| 5. |
- Maknys, K., et al.
(författare)
-
Electrical characterization of InGaAs/InP quantum wells by scanning capacitance microscopy
- 2003
-
Ingår i: Applied Physics Letters. - : AIP Publishing. - 0003-6951 .- 1077-3118. ; 83:20, s. 4205-4207
-
Tidskriftsartikel (refereegranskat)abstract
- In this work, cross-sectional scanning capacitance microscopy (SCM) is used to investigate InGaAs/InP quantum wells. It is demonstrated that SCM is indeed capable of detecting the electrons in the quantum wells and that the SCM signal shows a systematic trend for the different wells. Clear dips in the dC/dV signal are observed at the InGaAs quantum wells and imply carrier densities higher than the surrounding barriers. It is also shown that the depletion regions in the barriers adjacent to the wells can be resolved. The results show that geometric tip-averaging effects significantly influence the imaging of electrons in quantum wells and limit the lateral resolution.
|
|
| 6. |
- Maknys, K., et al.
(författare)
-
Probing carriers in two-dimensional systems with high spatial resolution by scanning spreading resistance microscopy
- 2003
-
Ingår i: Applied Physics Letters. - : AIP Publishing. - 0003-6951 .- 1077-3118. ; 83:11, s. 2184-2186
-
Tidskriftsartikel (refereegranskat)abstract
- In this work, cross-sectional scanning spreading resistance microscopy (SSRM) is used to profile carriers in quantum wells (QWs). The investigated structures consist of InGaAs wells of different widths sandwiched between Si-doped InP barriers. It is demonstrated that SSRM is indeed capable of detecting electrons in the quantum wells with high lateral resolution and that the SSRM signal shows a systematic trend for the different wells. Clear dips in the resistance signal are observed at the quantum wells and imply accumulated electron densities higher than in the surrounding barriers. Carrier density in the QW is found by using the calibration curve obtained from the resistance measurements on reference layers sample. It is also shown that only at certain appropriate tip-sample bias conditions the depletion regions in the barriers adjacent to the wells are resolved. Finally, we demonstrate that under very low forward biases the full width at half maximum of the observed resistance dips in SSRM data is nearly equal to the geometric QW widths.
|
|
| 7. |
- Osterman, J, et al.
(författare)
-
Techniques for depth profiling of dopants in 4H-SiC
- 2001
-
Ingår i: SILICON CARBIDE AND RELATED MATERIALS, ECSCRM2000. ; , s. 559-562
-
Konferensbidrag (refereegranskat)abstract
- Three different methods for measuring the depth distribution of dopants in 4H-SiC have been investigated: (I) Spreading Resistance profiling (SRP), (2) Scanning Capacitance Microscopy (SCM) and (3) Scanning Electron Microscopy (SEM). The investigated samples included p- and n-type epitaxial layers grown by vapor phase deposition with doping concentrations of 10(16)-10(20) cm(-3). Also p(+)n implanted profiles using a combination of Al and B multi-energy implantations were studied. All techniques were able to provide doping profiles qualitatively corresponding to secondary ion mass spectrometry (SIMS) data. The SRP results suggest a lower limit of the p-doping concentration below which the ohmic contact between the probe tip and sample becomes more Schottky-like. The magnitude of the SCM signal corresponds well to the chemical doping profile except in the depleted region surrounding the metallurgical junction of the p(+)n structure.
|
|
