| 1. |
- Artzi, M., et al.
(författare)
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Cortical reorganization following injury early in life
- 2016
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Ingår i: Neural Plasticity. - : Hindawi Publishing Corporation. - 2090-5904 .- 1687-5443.
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Tidskriftsartikel (refereegranskat)abstract
- The brain has a remarkable capacity for reorganization following injury, especially during the first years of life. Knowledge of structural reorganization and its consequences following perinatal injury is sparse. Here we studied changes in brain tissue volume, morphology, perfusion, and integrity in children with hemiplegia compared to typically developing children, using MRI. Children with hemiplegia demonstrated reduced total cerebral volume, with increased cerebrospinal fluid (CSF) and reduced total white matter volumes, with no differences in total gray matter volume, compared to typically developing children. An increase in cortical thickness at the hemisphere contralateral to the lesion (CLH) was detected in motor and language areas, which may reflect compensation for the gray matter loss in the lesion area or retention of ipsilateral pathways. In addition, reduced cortical thickness, perfusion, and surface area were detected in limbic areas. Increased CSF volume and precentral cortical thickness and reduced white matter volume were correlated with worse motor performance. Brain reorganization of the gray matter within the CLH, while not necessarily indicating better outcome, is suggested as a response to neuronal deficits following injury early in life.
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| 2. |
- Chen, Shangzhi, et al.
(författare)
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Conductive polymer nanoantennas for dynamic organic plasmonics
- 2020
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Ingår i: Nature Nanotechnology. - London : Nature Publishing Group. - 1748-3387 .- 1748-3395. ; 15
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Tidskriftsartikel (refereegranskat)abstract
- Being able to dynamically shape light at the nanoscale is oneof the ultimate goals in nano-optics1. Resonant light–matterinteraction can be achieved using conventional plasmonicsbased on metal nanostructures, but their tunability is highlylimited due to a fixed permittivity2. Materials with switchablestates and methods for dynamic control of light–matterinteraction at the nanoscale are therefore desired. Here weshow that nanodisks of a conductive polymer can supportlocalized surface plasmon resonances in the near-infraredand function as dynamic nano-optical antennas, with their resonancebehaviour tunable by chemical redox reactions. Theseplasmons originate from the mobile polaronic charge carriersof a poly(3,4-ethylenedioxythiophene:sulfate) (PEDOT:Sulf)polymer network. We demonstrate complete and reversibleswitching of the optical response of the nanoantennasby chemical tuning of their redox state, which modulatesthe material permittivity between plasmonic and dielectricregimes via non-volatile changes in the mobile chargecarrier density. Further research may study different conductivepolymers and nanostructures and explore their usein various applications, such as dynamic meta-optics andreflective displays.
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| 3. |
- Fath, MK, et al.
(författare)
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Revisiting characteristics of oncogenic extrachromosomal DNA as mobile enhancers on neuroblastoma and glioma cancers
- 2022
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Ingår i: Cancer cell international. - : Springer Science and Business Media LLC. - 1475-2867. ; 22:1, s. 200-
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Tidskriftsartikel (refereegranskat)abstract
- Cancer can be induced by a variety of possible causes, including tumor suppressor gene failure and proto-oncogene hyperactivation. Tumor-associated extrachromosomal circular DNA has been proposed to endanger human health and speed up the progression of cancer. The amplification of ecDNA has raised the oncogene copy number in numerous malignancies according to whole-genome sequencing on distinct cancer types. The unusual structure and function of ecDNA, and its potential role in understanding current cancer genome maps, make it a hotspot to study tumor pathogenesis and evolution. The discovery of the basic mechanisms of ecDNA in the emergence and growth of malignancies could lead researchers to develop new cancer therapies. Despite recent progress, different aspects of ecDNA require more investigation. We focused on the features, and analyzed the bio-genesis, and origin of ecDNA in this review, as well as its functions in neuroblastoma and glioma cancers.
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| 4. |
- Kang, Evan S. H., et al.
(författare)
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Hybrid plasmonic metasurfaces
- 2019
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Ingår i: Journal of Applied Physics. - : American Institute of Physics. - 0021-8979 .- 1089-7550. ; 126:14
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Tidskriftsartikel (refereegranskat)abstract
- Plasmonic metasurfaces based on ensembles of distributed metallic nanostructures can absorb, scatter, and in other ways shape light at the nanoscale. Forming hybrid plasmonic metasurfaces by combination with other materials opens up for new research directions and novel applications. This perspective highlights some of the recent advancements in this vibrant research field. Particular emphasis is put on hybrid plasmonic metasurfaces comprising organic materials and on concepts related to switchable surfaces, light-to-heat conversion, and hybridized light-matter states based on strong coupling.
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| 5. |
- Schertz, M., et al.
(författare)
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Imaging Predictors of Improvement from a Motor Learning-Based Intervention for Children with Unilateral Cerebral Palsy
- 2016
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Ingår i: Neurorehabilitation and Neural Repair. - : Sage Publications. - 1545-9683 .- 1552-6844. ; 30:7, s. 647-660
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Tidskriftsartikel (refereegranskat)abstract
- Background:Motor-learning interventions may improve hand function in children with unilateral cerebral palsy (UCP) but with inconsistent outcomes across participants. Objective. To examine if pre-intervention brain imaging predicts benefit from bimanual intervention.Method:Twenty children with UCP with Manual Ability Classification System levels I to III, aged 7-16 years, participated in an intensive bimanual intervention. Assessments included the Assisting Hand Assessment (AHA), Jebsen Taylor Test of Hand Function (JTTHF) and Children's Hand Experience Questionnaire (CHEQ) at baseline (T1), completion (T2) and 8-10 weeks post-intervention (T3). Imaging at baseline included conventional structural (radiological score), functional (fMRI) and diffusion tensor imaging (DTI).Results:Improvements were seen across assessments; AHA (P = 0.04), JTTHF (P <.001) and CHEQ (P < 0.001). Radiological score significantly correlated with improvement at T2; AHA (r =.475) and CHEQ (r =.632), but negatively with improvement on unimanual measures at T3 (JTTFH r = -.514). fMRI showed negative correlations between contralesional brain activation when moving the affected hand and AHA improvements (T2: r = -.562, T3: r = -0.479). Fractional Anisotropy in the affected posterior limb of the internal capsule correlated negatively with increased bimanual use on CHEQ at T2 (r = -547) and AHA at T3 (r = -.656).Conclusions: Children with greater structural, functional and connective brain damage showed enhanced responses to bimanual intervention. Baseline imaging may identify parameters predicting response to intervention in children with UCP.
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| 6. |
- Shiran, S. I., et al.
(författare)
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MRI-based radiologic scoring system for extent of brain injury in children with hemiplegia
- 2014
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Ingår i: American Journal of Neuroradiology. - : American Society of Neuroradiology. - 0195-6108 .- 1936-959X. ; 35:12, s. 2388-2396
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND AND PURPOSE:Brain MR imaging is recommended in children with cerebral palsy. Descriptions of MR imaging findings lack uniformity, due to the absence of a validated quantitative approach. We developed a quantitative scoring method for brain injury based on anatomic MR imaging and examined the reliability and validity in correlation to motor function in children with hemiplegia.MATERIALS AND METHODS:Twenty-seven children with hemiplegia underwent MR imaging (T1, T2-weighted sequences, DTI) and motor assessment (Manual Ability Classification System, Gross Motor Functional Classification System, Assisting Hand Assessment, Jebsen Taylor Test of Hand Function, and Children's Hand Experience Questionnaire). A scoring system devised in our center was applied to all scans. Radiologic score covered 4 domains: number of affected lobes, volume and type of white matter injury, extent of gray matter damage, and major white matter tract injury. Inter- and intrarater reliability was evaluated and the relationship between radiologic score and motor assessments determined.RESULTS:Mean total radiologic score was 11.3 ± 4.5 (range 4 -18). Good inter- (p = 0.909, P < .001) and intrarater (p = 0.926, P =<.001) reliability was demonstrated. Radiologic score correlated significantly with manual ability classification systems (p = 0.708, P < .001), and with motor assessments (assisting hand assessment [p = <0.753, P < .001]; Jebsen Taylor test of hand function [p = 0. 766, P < .001]; children's hand experience questionnaire [p=<0. 716, P < .001]), as well as with DTI parameters.CONCLUSIONS:We present a novel MR imaging- based scoring system that demonstrated high inter- and intrarater reliability and significant associations with manual ability classification systems and motor evaluations. This score provides a standardized radiologic assessment of brain injury extent in hemiplegic patients with predominantly unilateral injury, allowing comparison between groups, and providing an additional tool for counseling families.
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| 7. |
- Weinstein, M., et al.
(författare)
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Brain Plasticity following Intensive Bimanual Therapy in Children with Hemiparesis : Preliminary Evidence
- 2015
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Ingår i: Neural Plasticity. - : Hindawi Publishing Corporation. - 2090-5904 .- 1687-5443. ; 2015
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Tidskriftsartikel (refereegranskat)abstract
- Neuroplasticity studies examining children with hemiparesis (CH) have focused predominantly on unilateral interventions. CH also have bimanual coordination impairments with bimanual interventions showing benefits. We explored neuroplasticity following hand-Arm bimanual intensive therapy (HABIT) of 60 hours in twelve CH (6 females, mean age 11 ± 3.6 y). Serial behavioral evaluations and MR imaging including diffusion tensor (DTI) and functional (fMRI) imaging were performed before, immediately after, and at 6-week follow-up. Manual skills were assessed repeatedly with the Assisting Hand Assessment, Children's Hand Experience Questionnaire, and Jebsen-Taylor Test of Hand Function. Beta values, indicating the level of activation, and lateralization index (LI), indicating the pattern of brain activation, were computed from fMRI. White matter integrity of major fibers was assessed using DTI. 11/12 children showed improvement after intervention in at least one measure, with 8/12 improving on two or more tests. Changes were retained in 6/8 children at follow-up. Beta activation in the affected hemisphere increased at follow-up, and LI increased both after intervention and at follow-up. Correlations between LI and motor function emerged after intervention. Increased white matter integrity was detected in the corpus callosum and corticospinal tract after intervention in about half of the participants. Results provide first evidence for neuroplasticity changes following bimanual intervention in CH.
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| 8. |
- Weinstein, M., et al.
(författare)
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Interhemispheric and intrahemispheric connectivity and manual skills in children with unilateral cerebral palsy
- 2014
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Ingår i: Brain Structure and Function. - : Springer. - 1863-2653 .- 1863-2661. ; 219:3, s. 1025-1040
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Tidskriftsartikel (refereegranskat)abstract
- This study investigated patterns of motor brain activation, white matter (WM) integrity of inter- and intrahemispheric connectivity and their associations with hand function in children with unilateral cerebral palsy (CP-U). Fourteen CP-U (mean age 10.6 ± 2.7 years) and 14 typically developing children (TDC) underwent magnetic resonance imaging. CP-U underwent extensive motor evaluation. Pattern of brain activation during a motor task was studied in 12 CP-U and six TDC, by calculating laterality index (LI) and percent activation in the sensorimotor areas (around the central sulcus), and quantifying the activation in the supplementary motor area (SMA). Diffusivity parameters were measured in CP-U and eight other TDC for the corpus callosum (CC), affected and less affected cortico-spinal tracts (CST), and posterior limb of the internal capsule (PLIC). Abnormal patterns of brain activation were detected in areas around the central sulcus in 9/12 CP-U, with bilateral activation and/or reduced percent activation. More activation in areas around the central sulcus of the affected hemisphere was associated with better hand function. CP-U demonstrated more activation in the SMA when moving the affected hand compared to the less affected hand. CP-U displayed reduced WM integrity compared to TDC, in the midbody and splenium of the CC, affected CST and affected PLIC. WM integrity in these tracts was correlated with hand function. While abnormal pattern of brain activation was detected mainly when moving the affected hand, the integrity of the CC was correlated with function of both hands and bimanual skills. This study highlights the importance of interhemispheric connectivity for hand function in CP-U, which may have clinical implications regarding prognosis and management.
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