Dengue hemorrhagic encephalitis: MRI

History: 39 years male, known case of dengue with NS1 positive with altered sensorium.

MRI findings

Multiple ill defined, irregular, mild to moderately enhancing  mixed signal intensity lesions seen involving both thalami, pons, posterior midbrain, both frontoparietal  pariventricular white matter regions ( right thalamus & pons more than rest) with restricted diffusion   /reduced ADC values / patchy bright signal s on T1 / blooming on SW ( pons more than rest) with mass effect on 4^thventricle / mild proximal ventriculomegaly / moderate patchy meningeal  enhancement. Rest of the brain parenchyma & major dural  venous  sinuses  normal. Findings are likely suggestive of meningoencepalitis of dengue etiology, in view of history.

Discussion by Dr MGK Murthy, Dr GA Prasad

1. Dengue virus is a single-stranded RNA virus of the Flavivirus genus classified into four serotypes. Neurological manifestations, commonly seen with serotypes 2 and 3.
2. Neurological manifestation in dengue hemorrhagic fever usually results from multisystem dysfunction secondary to liver failure, cerebral hypoperfusion, electrolyte imbalance, shock, cerebral edema, and hemorrhage related to vascular leak.  Presentation as viral encephalitis is rare as the virus is non-neurotrophic.
3. Patients can  present with -  stroke, mononeuropathies, polyneuropathies, Guillain-Barre syndrome (GBS), myelitis, meningitis, acute disseminated encephalomyelitis (ADEM), encephalopathy, encephalitis, neuromyelitis optica, and optic neuritis.
4. Presence of dengue virus and anti-dengue IgM antibodies in patient's CSF with encephalitis suggests the possibility of direct cerebral invasion through infected macrophages.
5. Clinical differentials can be differentiated by MRI  -

•          Japanese encephalitis – bilateral thalamic and basal ganglia involvement .
•          Herpes encephalitis- bilateral temporal and basifrontal lobes lesions.
•         Chikungunya encephalitis - white matter lesions with restricted diffusion without hemorrhage or basal ganglia involvement.
•         Changes of ADEM in dengue fever are similar to Dengue  encephalitis on MRI and may not be possible to differentiate on MRI always.

There is no specific treatment for dengue encephalitis & treatment is mainly supportive.

Famous Radiology Blog http://ift.tt/1MM2hKr TeleRad Providers at http://ift.tt/1NgppuI Mail us at sales@teleradproviders.com

from Imaging via alkiviadis.1961 on Inoreader http://ift.tt/2jmcnts

Monitoring of uranium concentrations in water samples collected near potentially hazardous objects in North-West Tajikistan

Publication date: January 2018
Source:Journal of Environmental Radioactivity, Volume 181
Author(s): P. Zoriy, M. Schläger, K. Murtazaev, J. Pillath, M. Zoriy, B. Heuel-Fabianek
The water contamination near ecologically problematic objects was investigated between 2009 and 2014 in North-West Tajikistan as a part of a joint project between Forschungszentrum Jülich and Khujand State University. The main part of this work was the determination of uranium in water samples collected near the Degmay tailings dump, the Taboshar pit lake and the Syr Darya river. More than 130 water samples were collected and analyzed to monitor the uranium concentration near the investigated areas. Two different mass spectrometers and an ion chromatograph were used for element concentration measurements. Based on the results obtained, the uranium influence of the Degmay tailings on the rivers Khoja-Bakyrgan-Say and Syr Darya and surrounding water was not found. The uranium concentration in water samples was monitored for a lengthy period at seven locations Great differences in the uranium concentration in waters collected in 2010, 2011, 2012, 2013 for each location were not observed. Drinking water samples from the region of North-West Tajikistan were analyzed and compared with the World Health Organization's guidelines. Seven out of nine drinking water samples near Taboshar exceeded the WHO guideline value for uranium concentrations (30 μg/L). The average uranium concentration of water samples from Syr Darya for the period from 2009 to 2014 was determined to be 20.1 (±5.2) μg/L. The uranium contamination of the Syr Darya was determined from the western border to the eastern border and the results are shown in this paper.



from Imaging via alkiviadis.1961 on Inoreader http://ift.tt/2hre9ZS

Generalized Hybrid One-Step Block Method Involving Fifth Derivative for Solving Fourth-Order Ordinary Differential Equation Directly

A general one-step three-hybrid (off-step) points block method is proposed for solving fourth-order initial value problems of ordinary differential equations directly. A power series approximate function is employed for deriving this method. The approximate function is interpolated at while its fourth and fifth derivatives are collocated at all points ,, in the interval of approximation. Several fourth-order initial value problems of ordinary differential equations are then solved to compare the performance of the proposed method with the derived methods. The analysis of the method reveals that the method is consistent and zero stable concluding that the method is also convergent. The numerical results demonstrate the superiority of the new method over the existing ones in terms of error.

from #AlexandrosSfakianakis via Alexandros G.Sfakianakis on Inoreader http://ift.tt/2zBbYcS
via IFTTT

The Seduction of Curves revives old ideas about maths and beauty

René Thom's mathematical theorems passed their sell-by date in the 1970s, but applied to the human form, will they captivate a new generation?

from #AlexandrosSfakianakis via Alexandros G.Sfakianakis on Inoreader http://ift.tt/2zEZuiy
via IFTTT

Model Equations for Three-Dimensional Nonlinear Water Waves under Tangential Electric Field

We are concerned with gravity-capillary waves propagating on the surface of a three-dimensional electrified liquid sheet under a uniform electric field parallel to the undisturbed free surface. For simplicity, we make an assumption that the permittivity of the fluid is much larger than that of the upper-layer gas; hence, this two-layer problem is reduced to be a one-layer problem. In this paper, we propose model equations in the shallow-water regime based on the analysis of the Dirichlet-Neumann operator. The modified Benney-Luke equation and Kadomtsev-Petviashvili equation will be derived, and the truly three-dimensional fully localized traveling waves, which are known as “lumps” in the literature, are numerically computed in the Benney-Luke equation.

from #AlexandrosSfakianakis via Alexandros G.Sfakianakis on Inoreader http://ift.tt/2zx9jkU
via IFTTT

Commute Equilibrium for Mixed Networks with Autonomous Vehicles and Traditional Vehicles

Recent development of autonomous vehicle (AV) provides new travel opportunities for citizens, and traditional vehicles (TVs) will still be used for a long time. Therefore, it is highly possible that both AVs and TVs will be used as travel modes in a city. In a transportation system with both AVs and TVs, the traffic pattern is worthy of studying. This paper investigates user equilibrium traffic pattern based on the traditional bottleneck model considering AVs and TVs. For both TVs and AVs, travel costs include queuing delay and schedule delay. However, they also have different components of travel costs; more specifically, for AVs, passengers have to pay a riding fare, and, for TVs, travelers encounter a walking time cost after parking their cars. For different combinations of travel demands and riding fare of AVs, analytical solutions of three different user equilibrium traffic patterns are obtained. Finally, numerical examples are provided to demonstrate the usefulness of the analytical models. Sensitivity analyses are examined to show the impacts of AV’s time-dependent fee and trip-based fixed fee on the traffic pattern and travel costs.

from #AlexandrosSfakianakis via Alexandros G.Sfakianakis on Inoreader http://ift.tt/2zQtkUd
via IFTTT

Model Equations for Three-Dimensional Nonlinear Water Waves under Tangential Electric Field

We are concerned with gravity-capillary waves propagating on the surface of a three-dimensional electrified liquid sheet under a uniform electric field parallel to the undisturbed free surface. For simplicity, we make an assumption that the permittivity of the fluid is much larger than that of the upper-layer gas; hence, this two-layer problem is reduced to be a one-layer problem. In this paper, we propose model equations in the shallow-water regime based on the analysis of the Dirichlet-Neumann operator. The modified Benney-Luke equation and Kadomtsev-Petviashvili equation will be derived, and the truly three-dimensional fully localized traveling waves, which are known as “lumps” in the literature, are numerically computed in the Benney-Luke equation.

from #AlexandrosSfakianakis via Alexandros G.Sfakianakis on Inoreader http://ift.tt/2zx9jkU
via IFTTT