Molecular Dynamics Simulations of Heavy Ion Induced Defects in SiC Schottky Diodes

Heavy ion irradiation increases the leakage current in reverse-biased SiC Schottky diodes. This letter demonstrates, via molecular dynamics simulations, that a combination of bias and ion-deposited energy is required to produce the degradation.Peer reviewe

Prevalence and prognosis of Alzheimer's disease at the mild cognitive impairment stage

Vos et al. compare the prevalence and prognosis of Alzheimer's disease at the mild cognitive impairment stage based on the IWG-1, IWG-2 and NIA-AA criteria. All three aid identification of early Alzheimer's disease, but combining amyloid and neuronal injury markers according to the NIA-AA criteria offers the most accurate prognosi

Cognitive profiles of vascular and neurodegenerative MCI

The objective of the thesis was to investigate the cognitive profiles of different types of mild cognitive impairment (MCI) and follow their course over time. Would it be possible to differentiate between “benign” and “malign” forms of MCI, and identify different dementia disorders in their prodromal stages by means of cognitive profiles? In study I consecutive MCI subjects (N=112) were assessed with a neuropsyhological test battery of 21 tests. When compared to healthy controls (N=35) MCI subjects had impairments in all cognitive domains (speed/attention, memory and learning, visuospatial functions, language and executive functions), which contradicted the prevailing view of MCI typically being memory impairment, ”amnestic MCI”. In study II the subjects were grouped by cerebrovascular disease. Subjects with significant vascular disease (N=60) performed overall worse on the neuropsychological test battery than those without vascular disease (N=60). The most clear-cut differences were seen on speed/attention and executive tests, and the conclusion was that there were similarities in the cognitive profiles of MCI with vascular disease and vascular dementia. In study III MCI subjects without vascular disease were grouped by concentrations of the Alzheimer-typical biomarkers total-tau (T-tau) and beta-amyloid (Aß). Subjects with Alzheimer-typical concentrations of one or the other or both biomakers in cerebrospinal fluid (N=73) performed worse on episodic memory and speed/attention tests than those with normal concentrations (N=73). When subjects were grouped into those with only high T-tau, only low Aß and both high T-tau and low Aß, those with both high T-tau and low Aß tended to perform slightly worse, while the other two groups performed quite similarly. In study IV 175 subjects were followed up after two years. Forty-four converted to dementia, all with impairment in several cognitive domains at baseline, and all but two had either vascular disease or Alzheimer-typical biomarkers. Single domain MCI – regardless of vascular disease and biomarkers – had a benign prognosis over two years. The combination of multiple domain amnestic MCI and vascular disease was the best predictor of mixed and vascular dementia, while multiple domain amnestic MCI and biomarkers was the strongest predictor of Alzheimer’s disease. MCI is a heterogeneous condition – the original purely amnestic MCI was very rare – w ith several aetiologies. The combination of cognitive profiles and aetiologies has the potential of making a crucial contribution in diagnosing dementia disorders at their earliest manifestations

Cognitive impairment 3 years after neurological Varicella-zoster virus infection: a long-term case control study

Varicella-zoster virus (VZV) is one of the most common viruses causing central nervous system (CNS) infection, sometimes with severe neurological complications and sequelae despite appropriate antiviral treatment. Whether the neurological sequelae of VZV CNS infections include long-term cognitive impairment and how this impairment might affect the patients is still largely unknown. In this study, 14 patients with predominant CNS manifestations caused by VZV infection underwent cognitive testing 3 years (median 39.5 months, range 31-52 months) after acute disease. The results were compared with those for 28 controls, matched for age and gender. The tests covered the cognitive domains of speed and attention, memory and learning, visuospatial function, language and executive function. To further assess the cognitive dysfunction caused by neurological VZV infection, patients were classified into the concept of mild cognitive impairment (MCI), which is associated with development of dementia in other pathologies. The VZV patients performed significantly worse than controls on four tests covering the domains of speed and attention, memory and learning and executive function. The cut-off was set at 1.5 SD below mean age. In addition, a greater proportion of VZV patients were classified with MCI as compared with controls. In conclusion, patients with previous VZV infection affecting the brain had signs of long-term cognitive impairment in the domains of speed and attention, memory and learning and executive function. However, larger study populations are needed to confirm these results

The Combination of Dysexecutive and Amnestic Deficits Strongly Predicts Conversion to Dementia in Young Mild Cognitive Impairment Patients: A Report from the Gothenburg-Oslo MCI Study

Background/Aims: The present study aimed to add to the knowledge of mild cognitive impairment (MCI) by studying the prognosis in a relatively young cohort of patients characterized by neuropsychological criteria. Methods: Patients (mean age: 63 years) with cognitive complaints and MCI (n = 302) were recruited from two university clinics and followed for 2 years. Results: Pure dysexecutive MCI occurred in 11.7% of the neuropsychologically impaired patients, while 59.3 and 29.0% were characterized as having pure amnestic MCI or multidomain MCI. During the study period, the state of 2 (10.5%) of the patients with single-domain dysexecutive MCI converted to dementia, while 28 (29.2%) of the patients with pure amnestic MCI became demented. Of the patients with both executive and amnestic deficits, 28 (59.6%) became demented. Conclusion: The results suggest that dysexecutive symptoms in combination with amnestic symptoms constitute a strong risk factor for dementia in young MCI patients. A significant number of patients in all subgroups showed normal test results at follow-up, indicating that a neuropsychological diagnosis needs to be supported by imaging or biomarker data

Are there differences in the use of everyday technology among persons with MCI, SCI and older adults without known cognitive impairment

Erworben im Rahmen der Schweizer Nationallizenzen (http://www.nationallizenzen.ch)Background: To use valid subjective reports sensible to cognitive decline is vital to identify very early signs of dementia development. Use of everyday technology (ET) has been shown to be sensitive to differentiate adults with mild cognitive impairment (MCI) from controls, but the group with subjective cognitive impairment (SCI) has not yet been examined. This study aims to investigate and compare self-perceived ability in ET use and number of ETs reported as actually used in a sample of older adults with SCI, MCI, and older adults with no known cognitive impairment, i.e. controls. Methods: Older adults with MCI (n = 29), SCI ( n = 26), and controls (n = 30) were interviewed with the short version of the Everyday Technology Use Questionnaire (S-ETUQ) to capture self-perceived ability in ET use and number of ETs used. To generate individual measures of ability to use ET, Rasch analysis was used. The measures were then compared group-wise using ANCOVA. The numbers of ETs used were compared group-wise with ANOVA. Results: Controls versus SCI and MCI differed significantly regarding ETs reported as used, but not SCI versus MCI. Similarly, in ability to use ET, controls versus SCI and MCI differed significantly but not SCI versus MCI. Conclusions: The significantly lower numbers of ETs reported as actually used and the lower ability in SCI and MCI groups compared to controls suggest that ET use is affected already in very minor cognitive decline. This indicates that self-reported ET use based on the S-ETUQ is sensitive to detect changes already in SCI