68,733 research outputs found

    Comparison of prefrontal atrophy and episodic memory performance in dysexecutive Alzheimer’s disease and behavioural-variant frontotemporal dementia

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    Alzheimer’s disease (AD) sometimes presents with prominent executive dysfunction and associated prefrontal cortex atrophy. The impact of such executive deficits on episodic memory performance as well as their neural correlates in AD, however, remains unclear. The aim of the current study was to investigate episodic memory and brain atrophy in AD patients with relatively spared executive functioning (SEF-AD; n = 12) and AD patients with relatively impaired executive functioning (IEF-AD; n = 23). We also compared the AD subgroups with a group of behavioral-variant frontotemporal dementia patients (bvFTD; n = 22), who typically exhibit significant executive deficits, and age-matched healthy controls (n = 38). On cognitive testing, the three patient groups showed comparable memory profiles on standard episodic memory tests, with significant impairment relative to controls. Voxel-based morphometry analyses revealed extensive prefrontal and medial temporal lobe atrophy in IEF-AD and bvFTD, whereas this was limited to the middle frontal gyrus and hippocampus in SEF-AD. Moreover, the additional prefrontal atrophy in IEF-AD and bvFTD correlated with memory performance, whereas this was not the case for SEF-AD. These findings indicate that IEF-AD patients show prefrontal atrophy in regions similar to bvFTD, and suggest that this contributes to episodic memory performance. This has implications for the differential diagnosis of bvFTD and subtypes of AD

    Tandem internal electric fields in intralayer/interlayer carbon nitride homojunction with a directed flow of photo-excited electrons for photocatalysis

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    Photocatalytic hydrogen production is a green technology while significantly impeded by the sluggish and uncontrolled charge dynamics for less electron accumulation on catalyst surface. Herein, we proposed an effective strategy of epitaxial growth of a van der Waals (VDW) homojunction on an intralayer homojunction of carbon nitride for a controlled charge flow. Experimental and simulation collectively disclosed a tandem internal electric field (IEF) in the integrated hybrid, stringing a lateral IEF along the intralayer homojunction with a vertical IEF within the VDW homojunction. The planar IEF dominates laterally dispersive movement of charge carriers for their efficient separations and mobilities, meanwhile the vertical IEF induces an oriented accumulation of the dispersive hot electrons to the catalyst surface for intensified hydrogen reduction. The tandem IEF renders the hydrogen evolution rate at 3.5-fold higher than in-planar homojunction, and 6.3 times higher than g-C3N4 benchmark. This work realizes charge-directing dynamics for robust photocatalysis

    The influence of different connecting rod configurations on the stability of the Ilizarov Frame: A biomechanical study

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    Background: The Ilizarov external fixator (IEF) is frequently used in trauma and elective orthopaedics. Many of its biomechanical variables (ring size; wire diameter; wire number; half pins versus wires; etc.) and their influence on stability and stiffness have been investigated. There is however a paucity in the literature regarding the influence of the connecting rod numbers and configurations between the rings on IEF stability. Objectives: Primarily to compare the stability between four and three rod IEF configurations. Secondarily to assess the difference in stability between symmetrical and asymmetrical spacing of the IEF rods. Methods: A custom jig was designed to facilitate mounting of a basic two ring IEF in a hydraulic press. Controlled centre and off centre (thus simulated bending) axial loading was then applied across the frame. The configurations were loaded up to 4000 Newtons. The frame deformation was plotted and the data was then analysed and interpreted. Results: Negligible differences were observed between different four and three rod configurations as long as the applied force at the loading point (LP) was within the area of support (AOS) created by the rods. The different four rod constructs were always more stable than the three rod constructs during bending. Conclusions: There is comparable stiffness between a four rod and a three rod IEF construct as long as the loading point (LP) is within the area of support (AOS) created by the rods. A four rod IEF is stiffer than a three rod IEF in bending

    Protein fraction heterogeneity in donkey's milk analysed by proteomic methods

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    Donkey's milk is often well tolerate by patients affected by cow's milk protein allergy, probably thanks to its protein composition. This empiric evidence, confirmed by some clinical trials, needs to be better investigated. A preliminary survey on the protein fraction of donkey's milk was carried out: fifty-six individual milk samples have been collected and analysed by IEF and SDS-PAGE. Five different IEF patterns have been identified, showing a marked heterogeneity both in casein and whey protein fractions. A single IEF pattern showed an apparent reduced amount of casein fraction highlighted by SDS. Three of the five IEF patterns have been further investigated by Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry (MALDI-TOF MS)

    ZNAČAJ INTRAKARDIJALNIH EHOGENIH ŽARIŠTA FETALNOG SRCA: SADAŠNJE SHVAĆANJE I KLINIČKA VRIJEDNOST

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    Objective. To estimate the degree of risk of the echogenic intracardiac foci (IEF) for fetal chromosomopathies and to determine its association with structural anomalies of the fetus. Material and methods. During the period of two years 190 pregnant patients had been send for fetal echocardiography. Examination had been performed by transvaginal¬ (12–17 weeks of gestation) or transabdominal approach (18 weeks or more of gestation). Results. IEF was observed in 17 fetuses, multifocal appearance was found in 2 out of 17 fetuses. In 3 cases IEF had resolved during the 8 weeks period of time. Additional structural anomalies were detected in 11 fetuses. In 2 fetuses trisomy 21 had been confirmed. Conclusion. A single soft marker as IEF is commonly encountered during the second trimester among the fetuses with chromosomal aberation. As do many sonographic markers IEF can be resolved during the pregnancy and often can be found in normal fetuses.Cilj rada je bio na vlastitom uzorku utvrditi u kojoj mjeri ultrazvučni nalaz hiperehogenih intrakardijalnih žarišta (IEF) pridonosi dijagnostici kromosomopatija i strukturalnih anomalija. Uzorak i metode. Tijekom dvije godine 190 trudnica između 12. i 39. tjedna trudnoće je primljeno radi fetalne ehokardiografije. Pregled je obavljen vaginalnom sondom od 5 MHz pri trudnoćama 12.–17. tjedna ili zavinutom abdominalnom sondom od 3,5 MHz nakon 17. tjedna trudnoće. Rezultati. IEF su nađeni u 17 fetusa, multifokalni u 2 od njih. U 3 fetusa su IEF u roku od osam tjedana nestali. U 11 fetusa su nađene dodatne strukturalne anomalije. Trisomija 21 je potvrđena u 2 fetusa. Zaključak. IEF su »meki« ultrazvučni biljezi fetalne aneuploidije, često su prolazni, a nalaze se i u eukariotičnih fetusa

    Spatial Separation of the 3.29 micron Emission Feature and Associated 2 micron Continuum in NGC 7023

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    We present a new 0.9" resolution 3.29 micron narrowband image of the reflection nebula NGC 7023. We find that the 3.29 micron IEF in NGC 7023 is brightest in narrow filaments NW of the illuminating star. These filaments have been seen in images of K', molecular hydrogen emission lines, the 6.2 and 11.3 micron IEFs, and HCO+. We also detect 3.29 micron emission faintly but distinctly between the filaments and the star. The 3.29 micron image is in contrast to narrowband images at 2.09, 2.14, and 2.18 micron, which show an extended emission peak midway between the filaments and the star, and much fainter emission near the filaments. The [2.18]-[3.29] color shows a wide variation, ranging from 3.4-3.6 mag at the 2 micron continuum peak to 5.5 mag in the filaments. We observe [2.18]-[3.29] to increase smoothly with increasing distance from the star, up until the filament, suggesting that the main difference between the spatial distributions of the 2 micron continuum and the the 3.29 micron emission is related to the incident stellar flux. Our result suggests that the 3.29 micron IEF carriers are likely to be distinct from, but related to, the 2 micron continuum emitters. Our finding also imply that, in NGC 7023, the 2 micron continuum emitters are mainly associated with HI, while the 3.29 micron IEF carriers are primarily found in warm molecular hydrogen, but that both can survive in HI or molecular hydrogen. (abridged)Comment: to appear in ApJ, including 1 table and 8 figures, high resolution figures available at http://www.ast.cam.ac.uk/~jin/n7023

    Microchip Isoelectric Focusing Applications

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    This review summarizes all available publications on isoelectric focusing carried out on planar microfabricated devices. Characteristic features of microchip isoelectric focusing (MC-IEF), such as resolution independence of separation length and compression of pH gradient, are discussed. An overview of materials used for microchip fabrication and developed detection strategies is given. Accomplishments in on-chip coupling of MC-IEF with other electrophoretic separation techniques or with mass spectrometry are briefly described. The review ends with alternative approaches to MC-IEF separation in terms of unusual sample introduction, kinds of support used for IEF separation, and in manner in which the pH gradient is generated

    A qualitative investigation of major urinary proteins in relation to the onset of aggressive behavior and dispersive motivation in male wild house mice ( Mus musculus domesticus )

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    The physiological basis for population differentiation of dispersal timing during individual development in male wild house mice is still unknown. As major urinary proteins (MUPs) are known to convey information about competitive ability in male mice, we examined individual MUP profiles defined by isoelectric-focusing (IEF) patterns in relation to developmental timing of dispersive motivation. As an experimental paradigm marking the development of the dispersal propensity, we used agonistic onset between litter mate brothers when kept in pairs under laboratory conditions. Agonistic onset is known to reflect the initiation of dispersive motivation. Hence, we compared individual MUP IEF patterns between fraternal pairs that did or did not develop agonistic relationships before the age of 2months. Urine was collected on the day of weaning and at the beginning of adulthood. We investigated whether there was a significant co-occurrence of particular MUP IEF patterns with the agonistic onset in male mice. We assumed that, based on this co-occurrence, particular MUP IEF patterns and/or a particular dynamic of MUP IEF expression from weaning to adulthood may be considered a physiological predictor of a specific behavioral strategy in male mice (i.e. submissive-philopatric or agonistic-dispersive strategy). We found that agonistic males expressed more MUP IEF bands than amicable ones at weaning, but these differences disappeared later on. The presence of two particular IEF bands at weaning was significantly associated with early agonistic onset. Our study suggests that MUPs could have a predictive value for the onset of aggressive behavior and dispersal tendency in male wild house mic

    Multidimensional separation prior to mass spectrometry: Getting closer to the bottom of the iceberg

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    While prefractionation has previously been shown to improve results in MS analysis, a novel combination provides an additional dimension of separation: protein fractionation by SDS-PAGE followed by IEF of tryptic peptides before separation by RP-LC [Atanassov and Urlaub, Proteomics 2013, 13, 2947-2955]. This three-step separation procedure prior to MS/MS substantially increases proteome coverage and represents a further step toward a more comprehensive analysis of complex proteomes
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