The planetary spin and rotation period: A modern approach

Using a new approach, we have obtained a formula for calculating the rotation period and radius of planets. In the ordinary gravitomagnetism the gravitational spin ($S$) orbit ($L$) coupling, $\vec{L}\cdot\vec{S}\propto L^2$, while our model predicts that $\vec{L}\cdot\vec{S}\propto \frac{m}{M}\,L^2$, where $M$ and $m$ are the central and orbiting masses, respectively. Hence, planets during their evolution exchange $L$ and $S$ until they reach a final stability at which $MS\propto mL$, or $S\propto \frac{m^2}{v}$, where $v$ is the orbital velocity of the planet. Rotational properties of our planetary system and exoplanets are in agreement with our predictions. The radius ($R$) and rotational period ($D$) of tidally locked planet at a distance $a$ from its star, are related by, $D^2\propto \sqrt{\frac{M}{m^3}}\,\,R^3$ and that $R\propto \sqrt{\frac{m}{M}}\,\, a$.$a$ from its star, are related by, $D^2\propto \sqrt{\frac{M}{m^3}} R^3$ and that $R\propto \sqrt{\frac{m}{M}} a$.Comment: 13 LaTex pages, 1 figure; 7 Tables. Accepted for publication in Astrophysics and Space Scienc

From tip to tpa

We present the case of a 50 year old lady who presented with sudden onset altered sensorium, anarthria, right hemianopia, ophthalmoplegia, quadriparesis and abnormal posturing of upper limbs for 4 hours. The NIHSS score was 31. The CT brain showed early ischemic changes in left posterior cerebral artery territory. The CT cerebral angiogram showed occlusion of the tip of basilar artery. Intravenous thrombolysis with rtPA resulted in remarkable recovery and NIHSS improved to 3 within 6 hours. In view of expected severe disability associated with tip of basilar artery syndrome, intravenous thrombolysis can be rewarding even in patients with high NIHSS

Lead optimisation of dehydroemetine for repositioned use in malaria

Drug repositioning offers an effective alternative to de novo drug design to tackle the urgent need for novel anti-malarial treatments. The anti-amoebic compound, emetine dihydrochloride, has been identified as a potent in-vitro inhibitor of the multi-drug resistant strain K1 of Plasmodium falciparum (IC50: 47 nM ± 2.1 nM). Dehydroemetine, a synthetic analogue of emetine dihydrochloride has been reported to have less cardiotoxic effects than emetine. The structures of two diastereomers of dehydroemetine were modelled on the published emetine binding site on cryo-EM structure 3J7A (Pf 80S ribosome in complex with emetine) and it was found that (-)-R,S-dehydroemetine mimicked the bound pose of emetine more closely than (-)-S,S-dehydroisoemetine. (-)-R,S-dehydroemetine (IC50 71.03 ± 6.1 nM) was also found to be highly potent against the multi-drug resistant K1 strain of P. falciparum in comparison with (-)-S,S-dehydroisoemetine (IC50 2.07 ± 0.26 μM), which loses its potency due to the change of configuration at C-1′. In addition to its effect on the asexual erythrocytic stages of P. falciparum, the compounds exhibited gametocidal properties with no cross-resistance against any of the multi-drug resistant strains tested. Drug interaction studies showed (-)-R,S-dehydroemetine to have synergistic antimalarial activity with atovaquone and proguanil. Emetine dihydrochloride, and (-)-R,S-dehydroemetine failed to show any inhibition of the hERG potassium channel and displayed activity on the mitochondrial membrane potential indicating a possible multi-modal mechanism of action. [Abstract copyright: Copyright © 2020 Panwar et al.

A Comparison of Top Distributed Bragg Reflector for 1300 nm Vertical Cavity Semiconductor Optical Amplifiers Based on III–V Compound

In this work, the design of GaAs/AlGaAs distributed Bragg reflector (DBR) has been implemented for 1300 nm vertical cavity semiconductor optical amplifiers (VCSOAs) for optical fiber communication applications. The top DBR period and Al concentration are varied, the peak reflectivity of the DBR is increasing from 50% to 97.5% for 13 periods with increasing Al concentration, whereas the reflectivity bandwidth is increased to almost 190 nm. The relation between wavelength and incidence angle variation on DBR reflectivity is increasing with the incident angle (0°, 20°, 30°, and 50°), the resonant wavelength and bandwidth of the measured reflectance spectra shifts to shorter wavelength and wider bandwidth, respectively. In addition, a comparison between the linear, the graded, and the parabolic DBRs has been achieved with transfer matrix method using MATLAB software to show the influence of layer in DBRs and its effect on lasing wavelength. It is shown that using grading DBR mirror is much more beneficial compared to abrupt DBR, whereas it has lower reflectivity of almost 10% due to VCSOAs device which needs less number of top layers until prevent reaching lasing threshold

Bio-inspired artemether-loaded human serum albumin nanoparticles for effective control of malaria-infected erythrocytes

Aim: The intra-erythrocytic development of the malarial parasite is dependent on active uptake of nutrients, including human serum albumin (HSA), into parasitized red blood cells (pRBCs). We have designed HSA-based nanoparticles as a potential drug-delivery option for antimalarials. Methods: Artemether-loaded nanoparticles (AANs) were designed and antimalarial activity evaluated in vitro/in vivo using Plasmodium falciparum/Plasmodium berghei species, respectively. Results: Selective internalization of AAN into Plasmodium-infected RBCs in preference to healthy erythrocytes was observed using confocal imaging. In vitro studies showed 50% dose reduction for AAN as compared with drug-only controls to achieve IC50 levels of inhibition. The nanoparticles exhibited twofold higher peak drug concentrations in RBCs with antimalarial activity at 50% of therapeutic doses in P. bergei infected mice. Conclusion: Novel HSA-based nanoparticles offer safe and effective approach for selective targeting of antimalarial drugs

Experimental and Numerical Study of Inhaler Spray Characterization (Size Distributions and Velocity)

Particle size and velocity are two of the most significant factors that impact the deposition of pressurized metered-dose inhaler (pMDI) sprays in the mouth cavity. pMDIs are prominently used around the world in the treatment of patients suffering from a variety of lung diseases. Moreover, Soft Mist Inhalers (SMIs) are a new-generation of propellant-free Inhalers. The first delivery inhalation spray system of this kind is the Spiriva Respimat inhaler, which has its advantages, such as better medication delivering to the lungs. In the current study, particle velocity and size distribution are measured at three different locations along the centerline of the pMDI and the SMI spray using Phase Doppler Anemometry (PDA). pMDIs from four different pharmaceutical companies are tested, each pMDI using salbutamol sulfate as the medication, whereas the Spiriva Respimat inhaler using tiotropium bromide. Measurements along the pMDI centerline (at 0, 75, and 100 mm downstream of the inhaler mouthpiece) showed that the spray velocities were bimodal in time for all four pMDI brands. The first peak occurred as the spray was leaving the mouthpiece, while the second peak (at the same location, 0 mm) occurred at around 60, 95, 95, and 115 ms later, respectively, for the four tested inhalers, with a drop in the velocity between the two peaks. Three probability density functions (PDFs) were tested, and the Rosin-Rammler PDF best fit the empirical spray size distribution data. These results suggest that there is a difference in the mean particle velocities at the centerline for the tested pMDIs and the diameter of released particles varied statistically for each brand. Particle size distribution for the Spiriva Respimat inhaler using the Anderson Cascade Impactor (ACI) is also assessed. The results indicate that high percentage of inhaled medication was delivered to the lungs, which is still quite significant when compared to common pressurized metered dose inhalers. Computational fluid dynamics, implementing mean-flow and turbulent tracking of particles, is used to determine the ability of the software ANSYS CFX package, to emulate the Ventolin HFA spray behavior. The results exhibit very good agreement between both numerical and experimental results

Texture features analysis technique to detect mass lesion in digitized mammogram images

Mass lesions are one of the breast cancer tumors. Mammogram images are the first screening tool to detect tumors in the women breast, but due to radiologist fatigue, number of false positive (FP) and false negative (FN) rates are increased. The main objective of this paper is to develop an intelligent computer aided diagnosis (CAD) system that can accurately detect mass lesions in digitized mammogram images. The proposed method has three stages. The first stage is a preprocessing stage, where the mass lesion is enhanced using a customized Laplacian filter. Then, multi-statistical filters are implemented to detect a potential mass lesion in the mammogram images. In the final stage, the number detected FP regions are reduced using five texture features. The proposed algorithm is evaluated using 45 mammogram images and the algorithm achieved an accuracy rate of 97% in detecting mass lesion with 83% sensitivity rate and 98% specificity rate