Olfactory Neuroblastoma: Diagnostic Difficulty

Olfactory neuroblastoma is an uncommon malignant tumor of sinonasal tract arising from the olfactory neuro epithelium. The olfactory neuroblastomas presenting with divergent histomorphologies like, epithelial appearance of cells, lacking a neuro fibrillary background and absence of rosettes are difficult to diagnose. Such cases require immunohistochemistry to establish the diagnosis. We describe the clinical features, pathological and immunohistochemical findings of grade IV Olfactory neuroblastoma in a 57 year old ma

Two-Layered Pulsatile Blood Flow in a Stenosed Artery with Body Acceleration and Slip at Wall

Pulsatile flow of blood through an artery in presence of a mild stenosis has been investigated in this paper assuming the body fluid blood as a two-fluid model with the suspension of all the erythrocytes in the core region as Bingham Plastic and the peripheral region of plasma as a Newtonian fluid. This model has been used to study the influence of body acceleration, non- Newtonian nature of blood and a velocity slip at wall, in blood flow through stenosed arteries. By employing a perturbation analysis, analytic expressions for the velocity profile, Plug-core radius, flow rate, wall shear stress and effective viscosity, are derived. The variations of flow variables with different parameters are shown diagrammatically and discussed. It is noticed that velocity and flow rate increase but effective viscosity decreases, due to a wall slip. Flow rates and speed are enhanced further due to the influence of body acceleration

Pulsatile Flow of Blood in a Constricted Artery with Body Acceleration

Pulsatile flow of blood through a uniform artery in the presence of a mild stenosis has been investigated in this paper. Blood has been represented by a Newtonian fluid. This model has been used to study the influence of body acceleration and a velocity slip at wall, in blood flow through stenosed arteries. By employing a perturbation analysis, analytic expressions for the velocity profile, flow rate, wall shear stress and effective viscosity, are derived. The variations of flow variables with different parameters are shown diagrammatically and discussed. It is noticed that velocity and flow rate increase but effective viscosity decreases, due to a wall slip. Flow rate and speed enhance further due to the influence of body acceleration. Biological implications of this modeling are briefly discussed

Effects of gramicidin-A on the adsorption of phospholipids to the air–water interface

AbstractPrior studies suggest that the hydrophobic surfactant proteins, SP-B and SP-C, promote adsorption of the lipids in pulmonary surfactant to an air–water interface by stabilizing a negatively curved rate-limiting structure that is intermediate between bilayer vesicles and the surface film. This model predicts that other peptides capable of stabilizing negative curvature should also promote lipid adsorption. Previous reports have shown that under appropriate conditions, gramicidin-A (GrA) induces dioleoyl phosphatidylcholine (DOPC), but not dimyristoyl phosphatidylcholine (DMPC), to form the negatively curved hexagonal-II (HII) phase. The studies reported here determined if GrA would produce the same effects on adsorption of DMPC and DOPC that the hydrophobic surfactant proteins have on the surfactant lipids. Small angle X-ray scattering and 31P-nuclear magnetic resonance confirmed that at the particular conditions used to study adsorption, GrA induced DOPC to form the HII phase, but DMPC remained lamellar. Measurements of surface tension showed that GrA in vesicles produced a general increase in the rate of adsorption for both phospholipids. When restricted to the interface, however, in preexisting films, GrA with DOPC, but not with DMPC, replicated the ability of the surfactant proteins to promote adsorption of vesicles containing only the lipids. The correlation between the structural and functional effects of GrA with the two phospholipids, and the similar effects on adsorption of GrA with DOPC and the hydrophobic surfactant proteins with the surfactant lipids fit with the model in which SP-B and SP-C facilitate adsorption by stabilizing a rate-limiting intermediate with negative curvature

Direct Correlation between Short-Range Vibrational Spectral Diffusion and Localized Ion-Cage Dynamics of Water-in-Salt Electrolytes

The molecular dynamics simulations of a “water-in-salt” electrolyte, lithium bis(trifluoromethyl sulfonyl) imide (LiNTf2), with a varying concentration range of 3 to 20 m were performed to establish a direct connection between a dynamic property like the ion-cage lifetime with the short-range vibrational stretching frequency shift of the used probe, HOD. The properties reported here are compared to that obtained from experiments performed at the same concentrations. The time-series wavelet transform was adopted as a preferable mathematical tool for calculating the instantaneous fluctuating frequencies of the probe O-D stretch mode and the concentration-dependent vibrational stretch spectral signature based on the variable functions associated with a particular chemical bond derived from classical molecular dynamics trajectories. The decay time constants of frequency fluctuations and the lifetime of the ion cage (τIC) were estimated as a function of salt concentration. Herein, we emphasize the correlation between the slowest time constant (τ3) of the decay of O-D stretch frequency fluctuations and the timescales associated with the lifetime of ion cages (τIC). The results exhibit that the existing relationships were also concentration-dependent. Therefore, this study highlights the connection between the ionic motions that regulate the overall system dynamics with the short-range vibrational frequency shift of the used probe, which was used similar to experiments. It also provides an understanding of the interionic interactions and the dynamical and spectral properties of the electrolytic mixtures. We establish a direct correlation between short-range frequency profile and localized ion-cage lifetime, which can fill the gap of understanding between viscosity, vibrational frequency, and ion-cage dynamics of electrolytes

Correlation of clinical examination, ultrasound, magnetic resonance imaging and arthroscopy as diagnostic tools in shoulder pathology

Background: Shoulder pathologies can cause significant pain, discomfort, and affect the activity of daily living. The aim of this study was to compare the efficacy of clinical examination, ultrasound, magnetic resonance imaging (MRI) with shoulder arthroscopy in diagnosing various shoulder pathologies, considering shoulder arthroscopy as the gold standard tool.Methods: This was a prospective, comparative study conducted over 35 patients, between 18-75 years of age presenting with chronic shoulder pain or instability of more than 2 months duration. All patients were examined clinically, followed by high resolution ultrasound, MRI, arthroscopy of the affected shoulder.Results: The sensitivity and specificity of ultrasonography (USG) for diagnosing full thickness tear was 100% each and for MRI was 88% and 100% respectively. For subacromial impingement USG had sensitivity of 66.67%, specificity of 94.12%, positive predictive value of 50% and negative predictive value of 88.89%. For rotator cuff tear USG had sensitivity of 92.86%, specificity of 50%, positive predictive value of 81.25% and negative predictive value of 75% considering shoulder arthroscopy as gold standard.Conclusions: USG and MRI both are sensitive techniques for diagnosing of rotator cuff pathologies. USG has high accuracy in diagnosing partial thickness tears as compare to MRI. MRI proved to be superior in estimation of site and extent of tear. Considering shoulder arthroscopy as gold standard, it can be reserved for patients with suspicious of USG/MRI findings or those who may need surgical intervention simultaneously

Examining the predictors of successful Airbnb bookings with Hurdle models: evidence from Europe, Australia, USA and Asia-Pacific cities

Recent studies on Airbnb have examined the predictors of room prices, successful reservations and customer satisfaction. However, a preliminary investigation of the listings from twenty-two cities across four continents revealed that a significant number of Airbnb homes remained non-booked. Thus, Poisson count-regression techniques cannot efficaciously explain the effects of predictors of successful Airbnb bookings. To address this gap, we proposed a text mining framework using Hurdle-based Poisson and Negative Binomial regressions. We found that the superhost status, host response time, and communication with guests emerged as the most significant predictors irrespective of geographies. We also found that the instant booking option strongly influences the bookings across cities with incoming business visitors. Additionally, we presented a machine learning-based variable-importance scheme, which helps determine the top predictors of successful bookings, to design customized recommendations for attracting more guests and unique advertisement content on P2P accommodation platforms