| 1. |
- Tataranno, M. L., et al.
(author)
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Morphine affects brain activity and volumes in preterms: An observational multi-center study
- 2020
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In: Early Human Development. - : Elsevier BV. - 0378-3782 .- 1872-6232. ; 144
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Journal article (peer-reviewed)abstract
- Objective: We hypothesized that morphine has a depressing effect on early brain activity, assessed using quantitative aEEG/EEG parameter and depressed activity will be associated with brain volumes at term in extremely preterm infants. Study design: 174 preterm infants were enrolled in 3 European tertiary NICUs (mean GA:26 +/- 1wks) and monitored during the first 72 h after birth with continuous 2 channel aEEG. Six epochs of aEEG recordings were selected and minimum amplitude of aEEG (min aEEG), percentage of time amplitude< 5 mu V (% of time < 5 mu V), spontaneous activity transients (SATrate) and interSAT interval (ISI) were calculated. For infants receiving morphine, the cumulative morphine dosage was calculated. In a subgroup of 58 infants, good quality MRI at term equivalent age (TEA) and the cumulative morphine dose until TEA were available. The effects of morphine administration and cumulative dose on aEEG/EEG measures and on brain volumes were investigated. Results: Morphine administration had a significant effect on all quantitative aEEG/EEG measures, causing depression of early brain activity [longer ISI (beta 2.900), reduced SAT rate (beta -1.386), decreased min aEEG (beta -0.782), and increased % of time < 5 mu V (beta 14.802)] in all epochs. A significant effect of GA and postnatal age on aEEG/EEG measures was observed. Cumulative morphine dose until TEA had a significant negative effect on total brain volume (TBV) (beta -8.066) and cerebellar volume (beta -1.080). Conclusions: Administration of sedative drugs should be considered when interpreting aEEG/EEG together with the negative dose dependent morphine impact on brain development.
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| 2. |
- Cizmeci, Mehmet N, et al.
(author)
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Assessment of Brain Injury and Brain Volumes after Posthemorrhagic Ventricular Dilatation : A Nested Substudy of the Randomized Controlled ELVIS Trial
- 2019
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In: Journal of Pediatrics. - : Elsevier BV. - 1097-6833 .- 0022-3476. ; 208, s. 2-197
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Journal article (peer-reviewed)abstract
- OBJECTIVE: To compare the effect of early and late intervention for posthemorrhagic ventricular dilatation on additional brain injury and ventricular volume using term-equivalent age-MRI.STUDY DESIGN: In the Early vs Late Ventricular Intervention Study (ELVIS) trial, 126 preterm infants ≤34 weeks of gestation with posthemorrhagic ventricular dilatation were randomized to low-threshold (ventricular index >p97 and anterior horn width >6 mm) or high-threshold (ventricular index >p97 + 4 mm and anterior horn width >10 mm) groups. In 88 of those (80%) with a term-equivalent age-MRI, the Kidokoro Global Brain Abnormality Score and the frontal and occipital horn ratio were measured. Automatic segmentation was used for volumetric analysis.RESULTS: The total Kidokoro score of the infants in the low-threshold group (n = 44) was lower than in the high-threshold group (n = 44; median, 8 [IQR, 5-12] vs median 12 [IQR, 9-17], respectively; P < .001). More infants in the low-threshold group had a normal or mildly increased score vs more infants in the high-threshold group with a moderately or severely increased score (46% vs 11% and 89% vs 54%, respectively; P = .002). The frontal and occipital horn ratio was lower in the low-threshold group (median, 0.42 [IQR, 0.34-0.63]) than the high-threshold group (median 0.48 [IQR, 0.37-0.68], respectively; P = .001). Ventricular cerebrospinal fluid volumes could be calculated in 47 infants and were smaller in the low-threshold group (P = .03).CONCLUSIONS: More brain injury and larger ventricular volumes were demonstrated in the high vs the low-threshold group. These results support the positive effects of early intervention for posthemorrhagic ventricular dilatation.TRIAL REGISTRATION: ISRCTN43171322.
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| 3. |
- Osikowicz, Wojciech, 1974-, et al.
(author)
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Site-specific electronic structure of an oligo-ethylenedioxythiophene derivative probed by resonant photoemission
- 2005
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In: New Journal of Physics. - : IOP Publishing. - 1367-2630. ; 7
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Journal article (peer-reviewed)abstract
- A combination of conventional and resonant photoemission spectroscopy, x-ray absorption spectroscopy and ground-state quantum-chemical calculations has been used to study the valence electronic structure of a phenyl-capped 3,4-ethylenedioxythiophene oligomer, in polycrystalline thin films. The photon energy-dependent intensities of specific resonant decay channels are interpreted in terms of the spatial overlap of the excitation site and the ground-state molecular orbital involved in the decay. By making use of chemical shifts, excitations on different atomic sites are distinguished. It is demonstrated that site-specific information on the electronic structure of relatively large and complex organic systems may be obtained experimentally from non-radiative resonant decay spectra. In addition, these spectra provide relevant insight into the interpretation of near-edge x-ray absorption fine structure spectra. © IOP Publishing Ltd and Deutsche Physikalische Gesellschaft.
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| 4. |
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| 5. |
- Cizmeci, Mehmet N, et al.
(author)
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Randomized Controlled Early versus Late Ventricular Intervention Study in Posthemorrhagic Ventricular Dilatation : Outcome at 2 Years
- 2020
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In: Journal of Pediatrics. - : Elsevier BV. - 1097-6833 .- 0022-3476. ; 226, s. 3-35
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Journal article (peer-reviewed)abstract
- OBJECTIVE: To compare the effect of intervention at low vs high threshold of ventriculomegaly in preterm infants with posthemorrhagic ventricular dilatation on death or severe neurodevelopmental disability.STUDY DESIGN: This multicenter randomized controlled trial reviewed lumbar punctures initiated after either a low threshold (ventricular index of >p97 and anterior horn width of >6 mm) or high threshold (ventricular index of >p97 + 4 mm and anterior horn width of >10 mm). The composite adverse outcome was defined as death or cerebral palsy or Bayley composite cognitive/motor scores <-2 SDs at 24 months corrected age.RESULTS: Outcomes were assessed in 113 of 126 infants. The composite adverse outcome was seen in 20 of 58 infants (35%) in the low threshold group and 28 of 55 (51%) in the high threshold (P = .07). The low threshold intervention was associated with a decreased risk of an adverse outcome after correcting for gestational age, severity of intraventricular hemorrhage, and cerebellar hemorrhage (aOR, 0.24; 95% CI, 0.07-0.87; P = .03). Infants with a favorable outcome had a smaller fronto-occipital horn ratio (crude mean difference, -0.06; 95% CI, -0.09 to -0.03; P < .001) at term-equivalent age. Infants in the low threshold group with a ventriculoperitoneal shunt, had cognitive and motor scores similar to those without (P = .3 for both), whereas in the high threshold group those with a ventriculoperitoneal shunt had significantly lower scores than those without a ventriculoperitoneal shunt (P = .01 and P = .004, respectively).CONCLUSIONS: In a post hoc analysis, earlier intervention was associated with a lower odds of death or severe neurodevelopmental disability in preterm infants with progressive posthemorrhagic ventricular dilatation.TRIAL REGISTRATION: ISRCTN43171322.
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| 6. |
- Crispin, Xavier, et al.
(author)
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Conductivity, Morphology, Interfacial Chemistry, and Stability of Poly(3,4- ethylene dioxythiophene)–Poly(styrene sulfonate) : A Photoelectron Spectroscopy Study
- 2003
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In: Journal of Polymer Science Part B. - : John Wiley & Sons. - 0887-6266 .- 1099-0488. ; 41:21, s. 2561-2583
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Research review (peer-reviewed)abstract
- X-ray photoelectron spectroscopy (XPS) has been used to characterize poly(3,4-ethylene dioxythiophene)-poly(styrene sulfonate) (PEDT/PSS), one of the most common electrically conducting organic polymers. A correlation has been established between the composition, morphology, and polymerization mechanism, on the one hand, and the electric conductivity of PEDT/PSS, on the other hand. XPS has been used to identify interfacial reactions occurring at the polymer-on-ITO and polymer-on-glass interfaces, as well as chemical changes within the polymer blend induced by electrical stress and exposure to ultraviolet light.
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| 7. |
- de Jong, Michel P, et al.
(author)
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The electronic structure of n- and p-doped phenyl-capped 3,4-ethylenedioxythiophene trimer
- 2003
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In: Journal of Chemical Physics. - : AIP Publishing. - 0021-9606 .- 1089-7690. ; 118:14, s. 6495-6502
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Journal article (peer-reviewed)abstract
- A study was conducted on the effects of chemical doping on the chemical and electronic structure of condensed molecular solid films of the ethylenedioxythiophene (EDOT) trimer using ultraviolet photoelectron spectroscopy (UPS) and x-ray photoelectron spectroscopy (XPS). Phenyl-capped EDOT oligomers were potential candidates for molecular electronics applications and serve as model molecules for PEDOT. By combining UPS, XPS, and NEXAFS, a clear picture of the doping induced changes in the electronic structure of phenyl-capped EDOT-trimer was obtained.
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| 8. |
- Dean, J. M., et al.
(author)
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A Critical Review of Models of Perinatal Infection
- 2015
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In: Developmental Neuroscience. - : S. Karger AG. - 0378-5866 .- 1421-9859. ; 37:4-5, s. 289-304
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Research review (peer-reviewed)abstract
- One of the central, unanswered questions in perinatology is why preterm infants continue to have such poor long-term neurodevelopmental, cognitive and learning outcomes, even though severe brain injury is now rare. There is now strong clinical evidence that one factor underlying disability may be infection, as well as nonspecific inflammation, during fetal and early postnatal life. In this review, we examine the experimental evidence linking both acute and chronic infection/inflammation with perinatal brain injury and consider key experimental determinants, including the microglia response, relative brain and immune maturity and the pattern of exposure to infection. We highlight the importance of the origin and derivation of the bacterial cell wall component lipopolysaccharide. Such experimental paradigms are essential to determine the precise time course of the inflammatory reaction and to design targeted neuroprotective strategies to protect the perinatal brain from infection and inflammation. (C) 2015 S. Karger AG, Basel
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| 9. |
- Galinsky, R., et al.
(author)
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Magnesium Is Not Consistently Neuroprotective for Perinatal Hypoxia-Ischemia in Term-Equivalent Models in Preclinical Studies: A Systematic Review
- 2014
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In: Developmental Neuroscience. - : S. Karger AG. - 0378-5866 .- 1421-9859. ; 36:2, s. 73-82
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Journal article (peer-reviewed)abstract
- There is an important unmet need to further improve the outcome of neonatal encephalopathy in term infants. Meta-analyses of large controlled trials now suggest that maternal magnesium sulfate (MgSO4) therapy is associated with a reduced risk of cerebral palsy and gross motor dysfunction after premature birth, but that it has no effect on death or disability. Because of this inconsistency, it remains controversial whether MgSO4 is clinically neuroprotective and, thus, it is unclear whether it would be appropriate to test MgSO4 for treatment of encephalopathy in term infants. We therefore systematically reviewed the preclinical evidence for neuroprotection with MgSO4 before or after hypoxic-ischemic encephalopathy (HIE) in term-equivalent perinatal and adult animals. The outcomes were highly inconsistent between studies. Although there were differences in dose and timing of administration, there was evidence that beneficial effects of MgSO4 were associated with confounding mild hypothermia and, strikingly, the studies that included rigorous maintenance of environmental temperature or body temperature consistently suggested a lack of effect. On balance, these preclinical studies suggest that peripherally administered MgSO4 is unlikely to be neuroprotective. Rigorous testing in translational animal models of perinatal HIE is needed before MgSO4 should be considered in clinical trials for encephalopathy in term infants. (C) 2014 S. Karger AG, Basel
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| 10. |
- Hortensius, Lisa M., et al.
(author)
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Serum docosahexaenoic acid levels are associated with brain volumes in extremely preterm born infants
- 2021
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In: Pediatric Research. - : Springer Science and Business Media LLC. - 0031-3998 .- 1530-0447. ; 90:6, s. 1177-1185
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Journal article (peer-reviewed)abstract
- Background: Docosahexaenoic acid (DHA) and arachidonic acid (AA) are important for fetal brain growth and development. Our aim was to evaluate the association between serum DHA and AA levels and brain volumes in extremely preterm infants. Methods: Infants born at <28 weeks gestational age in 2013–2015, a cohort derived from a randomized controlled trial comparing two types of parenteral lipid emulsions, were included (n = 90). Serum DHA and AA levels were measured at postnatal days 1, 7, 14, and 28, and the area under the curve was calculated. Magnetic resonance (MR) imaging was performed at term-equivalent age (n = 66), and volumes of six brain regions were automatically generated. Results: After MR image quality assessment and area under the curve calculation, 48 infants were included (gestational age mean [SD] 25.5 [1.4] weeks). DHA levels were positively associated with total brain (B = 7.966, p = 0.012), cortical gray matter (B = 3.653, p = 0.036), deep gray matter (B = 0.439, p = 0.014), cerebellar (B = 0.932, p = 0.003), and white matter volume (B = 3.373, p = 0.022). AA levels showed no association with brain volumes. Conclusions: Serum DHA levels during the first 28 postnatal days were positively associated with volumes of several brain structures in extremely preterm infants at term-equivalent age. Impact: Higher serum levels of DHA in the first 28 postnatal days are positively associated with brain volumes at term-equivalent age in extremely preterm born infants.Especially the most immature infants suffer from low DHA levels in the first 28 postnatal days, with little increase over time.Future research is needed to explore whether postnatal fatty acid supplementation can improve brain development and may serve as a nutritional preventive and therapeutic treatment option in extremely preterm infants.
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| 11. |
- Jönsson, Stina, et al.
(author)
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Phenyl-capped EDOT trimer : its chemical and electronic structure and its interface with aluminum
- 2003
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In: Journal of Physical Chemistry B. - : American Chemical Society (ACS). - 1520-6106 .- 1520-5207. ; 107:39, s. 10793-10800
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Journal article (peer-reviewed)abstract
- The chemical and electronic properties of a phenyl-capped 3,4-(ethylenedioxy)thiophene trimer (EDOT trimer) and its interface formation with aluminum have been studied. Thin EDOT trimer films were prepared on clean gold substrates through in-situ vapor deposition. Aluminum was deposited stepwise on top of the EDOT trimer, and the initial stages of interface formation were investigated by photoelectron spectroscopy. The organic/metal interface formed was not completely abrupt; some degree of diffusion of aluminum into the EDOT trimer film occurred. The aluminum atoms preferentially react with the α-position of the trimer (C−S carbon atoms) forming covalent bonds. The formation of these covalent bonds causes a break in the π-conjugation of the system due to the introduction of sp3 defects. The charge density also is somewhat redistributed within the oligomer as a whole, mainly affecting the neighboring atoms: sulfur and β-position of the trimer (C=C−O carbon atoms). Once the C−S carbon sites are saturated, the aluminum instead reacts with the less favorable carbon atom of the ethylene bridge (C−O−C carbons). Worth noting is the decrease in work function from 5.2 eV for sputter cleaned gold to 4.1 eV upon deposition of the EDOT trimer. Our results have several implications for organic electronics. The sp3 defects introduced by the aluminum−EDOT contacting will influence the charge injection into the material across the EDOT trimer/aluminum interface negatively. The change in work function could potentially be used to modify gold contacts for electron injection into molecules with low electron affinity.
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| 12. |
- Kontio, T., et al.
(author)
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Early neurophysiology and MRI in predicting neurological outcome at 9-10 years after birth asphyxia
- 2013
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In: Clinical Neurophysiology. - : Elsevier BV. - 1388-2457 .- 1872-8952. ; 124:6, s. 1089-1094
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Journal article (peer-reviewed)abstract
- Objective: To assess whether early somatosensory evoked potentials (SEP) predict long-term neurodevelopmental outcome in normothermic, full-term infants with mild to moderate neonatal encephalopathy (NE), and to compare their predictive value to already available amplitude integrated EEG (aEEG) and magnetic resonance imaging (MRI). Methods: Fifty-six infants with post-asphyxia NE were prospectively recruited, and their SEP, aEEG and MRI data were acquired during the first five days. Follow-up continued to 9-10 years for assessment of neuromotor and neurocognitive development. We analysed SEP latency (N1 component), normality of aEEG background pattern, as well as patterns of injury on the neonatal MRI. Neurological outcome measures at 9-10 years included conventional MRI, Movement-ABC and the WISC-III NL. Results: A SEP latency <50 ms during the first five days was associated with a normal neuromotor outcome (p < 0.03), and a prolonged day 3 latency was associated with lower childhood IQ (p = 0.02). The presence of multiple seizures in aEEG, as well as a moderate or severe injury on the neonatal MRI was associated with a poor neuromotor score (p = 0.03 and p < 0.01, respectively). Combination of multiple techniques improved prediction of long-term outcome compared to single modality. Conclusion: Early SEPs provide information that is comparable to the already available aEEG and MRI paradigms in the prediction of long-term outcome of full-term infants with mild to moderate neonatal encephalopathy. Significance: The present results call for further studies using early SEP to aid early assessment of infants treated with hypothermia.
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| 13. |
- Marciniak Braun, Slawomir, et al.
(author)
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Light Induced Damage in Poly(3,4-ethylenedioxythiophene) and its Derivatives Studied by Photoelectron Spectroscopy
- 2004
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In: Synthetic metals. - : Elsevier. - 0379-6779 .- 1879-3290. ; 141:1-2, s. 67-73
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Journal article (peer-reviewed)abstract
- Poly(3,4-ethylenedioxythiophene), usually known as PEDOT, and derivatives have attracted significant interest because of their high electrical conductivity. This electric property, however, deteriorates upon exposure to solar radiation. X-ray photoelectron spectroscopy (XPS) has been used to study the UV-light-induced chemical changes in doped PEDOT, as well as in both neutral and doped forms of its alkylated derivative—PEDOT-C14H29. Analysis of the XPS data indicates an oxidation of the sulfur in the thiophene ring. Apparently, photo-oxidation leads to the formation of sulfon groups, SO2, resulting in a disruption of π-conjugation in PEDOT, which there by diminishes the conductivity of the organic layer. This hypothesis is supported by the results of a study of model molecules for pristine and the oxidized PEDOT unit: 3,4 ethylenedioxythiophene (EDOT) and 3,4 ethylenedioxythiophene and S-dioxide (EDOT-SO2), respectively.
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| 14. |
- Osikowicz, Wojciech, et al.
(author)
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A joint theoretical and experimental study on the electronic properties of phenyl-capped 3,4-ethylenedioxythiophene oligomers
- 2003
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In: Journal of Chemical Physics. - : AIP Publishing. - 0021-9606 .- 1089-7690. ; 119:19, s. 10415-10420
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Journal article (peer-reviewed)abstract
- The electronic structure of a series of phenyl-capped EDOT oligomers was studied using ultraviolet photoelectron spectroscopy, in combination with quantum-chemical methods. The bulk IP of the neutral PEDOT polymer was estimated to be 4.2 eV. The frontier band structue was predicted from the evolution of the spectral features in the studied series of oligomers.
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| 15. |
- Toet, M C, et al.
(author)
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Amplitude integrated EEG 3 and 6 hours after birth in full term neonates with hypoxic-ischaemic encephalopathy
- 1999
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In: Archives of disease in childhood. Fetal and neonatal edition. - 1359-2998. ; 81:1, s. 19-23
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Journal article (peer-reviewed)abstract
- AIM: To assess the prognostic value of amplitude integrated EEG (aEEG) 3 and 6 hours after birth. METHODS: Seventy three term, asphyxiated infants were studied (from two different centres), using the Cerebral Function Monitor (CFM Lectromed). The different aEEG tracings were compared using pattern recognition (flat tracing mainly isoelectric (FT); continuous extremely low voltage (CLV); burst-suppression (BS); discontinuous normal voltage (DNV); continuous normal voltage (CNV)) with subsequent outcome. RESULTS: Sixty eight infants were followed up for more than 12 months (range 12 months to 6 years).Twenty one out of 68 infants (31%) showed a change in pattern from 3 to 6 hours, but this was only significant in five cases (24%). In three this changed from BS to CNV with a normal outcome. One infant showed a change in pattern from CNV to FT and had a major handicap at follow up. Another infant showed a change in pattern from DNV to BS, and developed a major handicap at follow up. The other 16 infants did not have any significant changes in pattern: 11 infants had CLV, BS, or FT at 3 and 6 hours and died (n = 9) in the neonatal period or developed a major handicap (n = 2). Five infants had a CNV or DNV pattern at 3 and 6 hours, with a normal outcome. The sensitivity and specificity of BS, together with FT and CLV, for poor outcome at 3 hours was 0.85 and 0.77, respectively; at 6 hours 0.91 and 0.86, respectively. The positive predictive value (PPV) was 78% and the negative predictive value (NPV) 84% 3 hours after birth. At 6 hours the PPV was 86% and the NPV was 91%. CONCLUSION: aEEG could be very useful for selecting those infants who might benefit from intervention after birth asphyxia.
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| 16. |
- Zotti, G., et al.
(author)
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Electrochemical and XPS studies toward the role of monomeric and polymeric sulfonate counterions in the synthesis, composition, and properties of poly(3,4-ethylenedioxythiophene)
- 2003
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In: Macromolecules. - : American Chemical Society (ACS). - 0024-9297 .- 1520-5835. ; 36:9, s. 3337-3344
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Journal article (peer-reviewed)abstract
- Electrochemically prepared poly(3,4-ethylenedioxythiophene) (PEDT) poly(styrenesulfonate) (PSS), produced from acidic (PSSH) and basic (PSSNa) PSS, was characterized by cyclic voltammetry CV, UV-vis spectroscopy, in situ conductivity, and XPS spectroscopy and was compared with electrochemically prepared PEDT/tosylate and chemically prepared PEDT/PSS. CV analysis shows that the polymer synthesis is strongly affected by the nucleophilic character of the counteranion. Although CV and UV-vis spectroscopy show that the structure and degree of polymerization (oligomeric, ca. 10 EDT units) of the PEDT backbone is the same for all polymers, XPS is able to explain the different conductivity values for these materials (ranging from 1 S cm-1 for PEDT/PSSNa to 400-450 S cm-1 for PEDT/tosylate) based on doping level and composition. In particular, critical results are observed to be the ratios between sulfonate and thiophene units in the polymers: the higher the PEDT concentration, the higher the conductivity. XPS also explains by solvent-induced nanometer-scale segregation between PEDT/PSS and excess PSS particles the often reported conductivity enhancement of chemically prepared PEDT/PSS upon treatment with polar solvents.
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