Although neuroimaging plays an important role in the diagnosis of idiopathic normal pressure hydrocephalus, its predictive value for response to shunt surgery has not been established. The purpose of ...the current study was to identify neuroimaging markers that predict the shunt response of idiopathic normal pressure hydrocephalus.
Sixty patients with idiopathic normal pressure hydrocephalus underwent presurgical brain MR imaging and clinical evaluation before and 1 year after shunt surgery. The assessed MR imaging features included the Evans index, high-convexity tightness, Sylvian fissure dilation, callosal angle, focal enlargement of the cortical sulci, bumps in the lateral ventricular roof, and deep white matter and periventricular hyperintensities. The idiopathic normal pressure hydrocephalus grading scale total score was used as a primary clinical outcome measure. We used measures for individual symptoms (ie, the idiopathic normal pressure hydrocephalus grading scale subdomain scores, such as gait, cognitive, and urinary scores), the Timed Up and Go test, and the Mini-Mental State Examination as secondary clinical outcome measures. The relationships between presurgical neuroimaging features and postoperative clinical changes were investigated by using simple linear regression analysis. To identify the set of presurgical MR imaging features that best predict surgical outcomes, we performed multiple linear regression analysis by using a bidirectional stepwise method.
Simple linear regression analyses demonstrated that presurgical high-convexity tightness, callosal angle, and Sylvian fissure dilation were significantly associated with the 1-year changes in the clinical symptoms. A multiple linear regression analysis demonstrated that presurgical high-convexity tightness alone predicted the improvement of the clinical symptoms 1 year after surgery.
High-convexity tightness is a neuroimaging feature predictive of shunt response in idiopathic normal pressure hydrocephalus.
Charge ordering (CO) is a phenomenon in which electrons in solids crystallize into a periodic pattern of charge-rich and charge-poor sites owing to strong electron correlations. This usually results ...in long-range order. In geometrically frustrated systems, however, a glassy electronic state without long-range CO has been observed. We found that a charge-ordered organic material with an isosceles triangular lattice shows charge dynamics associated with crystallization and vitrification of electrons, which can be understood in the context of an energy landscape arising from the degeneracy of various CO patterns. The dynamics suggest that the same nucleation and growth processes that characterize conventional glass-forming liquids guide the crystallization of electrons. These similarities may provide insight into our understanding of the liquid-glass transition.
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BFBNIB, NMLJ, NUK, ODKLJ, PNG, SAZU, UL, UM, UPUK
Direct numerical simulations are carried out to investigate the role of the turbulent region in a self-sustaining system with a spiral vortex structure in the three-dimensional boundary layer over a ...rotating disk by solving the full Navier–Stokes equations. Two computational domains with two different azimuthal sizes,
$2\unicodeSTIX{x03C0}/68$
and
$2\unicodeSTIX{x03C0}/32$
, are used to deal with different initially dominant wavenumbers. An artificial disturbance is introduced by short-duration strong suction and blowing on the disk surface. After the flow field reaches a steady state, a turbulent region forms downstream of
$Re=640$
. The turbulent region is then removed using two methods: a sponge region, and application of a slip condition at the wall. In both cases, the turbulent region disappears, leaving the spiral vortex structure upstream unaffected. The results suggest that the downstream turbulent region is not related to the velocity fluctuations that grow by the global instability. In addition, when the area where the slip condition is applied is changed from
$Re>630$
to
$Re>610$
, the velocity fluctuations decay. The results indicate that the vibration source of the velocity fluctuations which grow by the global instability is located between
$Re=611$
and
$Re=630$
.
Geometrical relationships and interactions among hierarchical structures in isotropic turbulence are investigated by identifying individual vortices of three different scales in the inertial ...subrange. Fourier bandpass filters are employed to extract the vortices, and each extracted vortex is replaced by a group of vortex segments with a cylindrical shape. The axes of neighboring vortices tend to be anti-parallel when the distance between them is equivalent to their diameter. Further, results indicate that a vortex is most strongly stretched by vortices twice the scale irrespective of the Reynolds number and the vortex scales. Then, the geometric relationships between the vortices being stretched and those that cause the stretching are analyzed, and the stretching is found to be particularly strong when the two vortices are orthogonal to each other.
Cognitive and behavioural symptoms represent primary clinical manifestations of anterior thalamic infarcts (ATIs) in the tuberothalamic artery territory. The aim of the study is to understand the ...pathomechanism of cognitive and behavioural disturbances in left ATI (LATI).
6 patients with isolated LATIs were investigated using neuropsychological assessments, MRI stereotactic lesion localisation and positron emission tomography.
The patients were characterised clinically by verbal memory impairment, language disturbances dominated by anomia and word-finding difficulty and apathy. The ventral anterior nucleus (VA) proper, magnocellular VA (VAmc), ventral lateral anterior nucleus (VLa), ventral lateral posterior nucleus (VLp) and mammillothalamic tract were involved in all patients. Compared with healthy controls, the regional cerebral blood flow was lower in the thalamus, the dorsolateral, medial and orbital frontal lobes, the anterior temporal lobe, the inferior parietal lobule and the occipital lobe of the left hemisphere.
The authors propose that the Papez circuit disruption at the mammillothalamic tract and possibly thalamomedial temporal disconnection at the VA region is responsible for memory impairment and that the thalamo-anterior temporal disconnection is associated with language disturbance in LATI, respectively.
The dineutron correlation is systematically studied in three different Borromean nuclei near the neutron dripline, 11Li, 14Be and 17B, via the (p,pn) knockout reaction measured at the RIBF facility ...in RIKEN. For the three nuclei, the correlation angle between the valence neutrons is found to be largest in the same range of intrinsic momenta, which can be associated to the nuclear surface. This result reinforces the prediction that the formation of the dineutron is universal in environments with low neutron density, such as the surface of neutron-rich Borromean nuclei.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
The receptivity of the Blasius boundary layer over a semi-infinite flat plate with an elliptic leading edge and of aspect ratio five was investigated using a direct numerical solution of ...two-dimensional Navier-Stokes equations. The result of the computation where the slip condition is applied to the fluctuating component of velocity at the wall surface is compared with that of an ordinary computation using a nonslip condition. Another numerical experiment is performed where no vorticity fluctuation is supplied from a freestream while prerecorded values of vorticities at the wall in response to the passage of convecting fluctuations are used as the wall vorticity boundary condition. It is shown that vorticity fluctuations in the boundary layer can be classified according to their wavelengths. Waves with longer wavelengths originate from the freestream, whereas waves with shorter wavelengths close to T-S waves originate from the surface of the plate. In another numerical experiment, the slip boundary condition against the fluctuation component of vorticity is applied to the limited area of the wall surface. The aim of the study is to determine the part of the elliptic leading edge or flat plate that induces vorticity fluctuations, thereby resulting in the creation of T-S waves. The numerical results show that the contribution of vorticity fluctuations originating from the juncture is the most crucial, whereas the vorticities supplied in the elliptic leading-edge surface negatively affect the amplitude of vorticity fluctuations inside the boundary layer. And, the stagnation section did not show positive contribution.
Aims
Establishment of an efficient isoprene fermentation process by adopting inorganic phosphate limitation as the trigger to direct metabolic flux to the isoprene synthetic pathway.
Methods and ...Results
We constructed isoprene‐producing strains of Pantoea ananatis (a member of the Enterobacteriaceae family) by integrating a heterologous mevalonate pathway and a metabolic switch that senses external inorganic phosphate (Pi) levels. This metabolic switch enabled dual‐phase isoprene production, where the initial cell growth phase under Pi‐saturating conditions was uncoupled from the subsequent isoprene production phase under Pi‐limiting conditions. In fed‐batch fermentation using our best strain (SWITCH‐PphoC/pIspSM) in a 1‐l bioreactor, isoprene concentration in the off‐gas was maintained between 300 and 460 ppm during the production phase and at 20 ppm during the cell growth phase, respectively. The strain SWITCH‐PphoC/pIspSM produced totally 2·5 g l−1 of isoprene from glucose with a 1·8% volumetric yield in 48 h.
Conclusions
This proof‐of‐concept study demonstrated that our Pi‐dependent dual‐phase production system using a P. ananatis strain as a producer has potential for industrial‐scale isoprene fermentation.
Significance and Impact of the Study
This Pi‐dependent dual‐phase fermentation process could be an attractive and economically viable option for the production of various commercially valuable isoprenoids.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Background: The relationship between corticolimbic involvement and cognitive dysfunction in non‐demented Parkinson’s disease (PD) patients has not yet been elucidated.
Objectives: To delineate ...involvement of the cerebral cortex and limbic structures in non‐demented PD and to clarify distributional differences of gray matter loss between non‐demented PD with impaired cognition (PD‐CI) and without cognitive impairment (PD‐NC).
Methods: Operational criteria based on the Clinical Dementia Rating were used to identify PD‐CI. Of 40 consecutive non‐demented patients with PD, 13 were classified as PD‐CI and 27 as PD‐NC. Comparisons of regional gray matter volume (rGMV) were made amongst the PD‐CI, PD‐NC, and control groups using voxel‐based morphometry.
Results: Gray matter loss was found extensively in the frontal, temporal, parietal, and occipital cortices in the present non‐demented patients with PD. rGMV in the medial frontal and medial occipital cortices was reduced comparably in the PD‐NC and PD‐CI groups. The severity of gray matter loss in the perisylvian cortices increased in order from the control, to the PD‐NC, to the PD‐CI groups. rGMV reduction in the lateral and orbital frontal, medial and lateral temporal, medial and lateral parietal, and lateral occipital cortices and cerebellum was found specifically in PD‐CI.
Conclusions: Our results suggest that corticolimbic degeneration occurs in non‐demented patients with PD, and extensive involvement of the limbic and posterior cortical regions as well as the frontal cortices is associated with cognitive impairment in PD.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
In this study, attempts to suppress numerical viscosity in incompressible smoothed particle hydrodynamics (SPH) computations are reported. Two-dimensional computations are performed for inviscid and ...viscous flows to evaluate the effects of numerical viscosity suppression. The first approach is to reduce numerical viscosity at the wall by considering only the wall-normal components of the forces between fluid particles and wall particles. The second approach is to reduce numerical viscosity within the flow field by employing elliptic kernel functions whose major axes are aligned with the local mean flow direction. It is found that special treatment of the wall radically reduces the numerical wall friction. Using an elliptic kernel function is found to work reasonably well in reducing numerical viscosity.
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