Background
Medical research has evolved from individual expert-described opinions and techniques to scientifically designed methodology-based studies. There are different study designs, and selecting ...an appropriate study design is critical to appropriately answer the research question being investigated.
Main body
A research question may be addressed using different approaches that can be descriptive, analytical, or experimental. The choice of study design is influenced by features as that related to exposure (intervention) and disease (outcome); considerations related to time, resources, ethics and gaps in scientific knowledge that remain to be filled. The purpose of this review is to provide an overview of the basic study designs as it is the foundation of neurosurgical research to provide valid scientific evidence.
Conclusion
Quality in scientific research begins with a clear hypothesis and a well-formulated design. This entails a thorough understanding of the different study designs to choose the best suited to answer the investigated research question.
Machine learning models are used today to solve problems within a broad span of disciplines. If the proper hyperparameter tuning of a machine learning classifier is performed, significantly higher ...accuracy can be obtained. In this paper, a comprehensive comparative analysis of various hyperparameter tuning techniques is performed; these are Grid Search, Random Search, Bayesian Optimization, Particle Swarm Optimization (PSO), and Genetic Algorithm (GA). They are used to optimize the accuracy of six machine learning algorithms, namely, Logistic Regression (LR), Ridge Classifier (RC), Support Vector Machine Classifier (SVC), Decision Tree (DT), Random Forest (RF), and Naive Bayes (NB) classifiers. To test the performance of each hyperparameter tuning technique, the machine learning models are used to solve an Arabic sentiment classification problem. Sentiment analysis is the process of detecting whether a text carries a positive, negative, or neutral sentiment. However, extracting such sentiment from a complex derivational morphology language such as Arabic has been always very challenging. The performance of all classifiers is tested using our constructed dataset both before and after the hyperparameter tuning process. A detailed analysis is described, along with the strengths and limitations of each hyperparameter tuning technique. The results show that the highest accuracy was given by SVC both before and after the hyperparameter tuning process, with a score of 95.6208 obtained when using Bayesian Optimization.
Oxidative stress and a series of excessive inflammatory responses are major obstacles for neurological functional recovery after ischemic stroke. Effective noninvasive anti-inflammatory therapies are ...urgently needed. However, unsatisfactory therapeutic efficacy of current drugs and inadequate drug delivery to the damaged brain are major problems. Nanozymes with robust anti-inflammatory and antioxidative stress properties possess therapeutic possibility for ischemic stroke. However, insufficiency of nanozyme accumulation in the ischemic brain by noninvasive administration hindered their application. Herein, we report a neutrophil-like cell-membrane-coated mesoporous Prussian blue nanozyme (MPBzyme@NCM) to realize noninvasive active-targeting therapy for ischemic stroke by improving the delivery of a nanozyme to the damaged brain based on the innate connection between inflamed brain microvascular endothelial cells and neutrophils after stroke. The long-term
therapeutic efficacy of MPBzyme@NCM for ischemic stroke was illustrated in detail after being delivered into the damaged brain and uptake by microglia. Moreover, the detailed mechanism of ischemic stroke therapy
MPBzyme@NCM uptake by microglia was further studied, including microglia polarization toward M2, reduced recruitment of neutrophils, decreased apoptosis of neurons, and proliferation of neural stem cells, neuronal precursors, and neurons. This strategy may provide an applicative perspective for nanozyme therapy in brain diseases.
Abstract
The current article aims to examine the magnetohydrodynamics (MHD) impact on the flow of MgO–Ag/water-based hybrid nanoliquid with motile microorganisms and the fluid is allowed to flow over ...a Riga plate subject to slip effects and activation energy. Furthermore, the presence of a uniform heat source/sink is also addressed in the energy equation. In addition to this, the thermophoresis effect is highlighted in the concentration equation. From the present proposed model, we get a non-linear system of the governing equations. The obtained system of partial differential equations (PDEs) is converted to the dimensionless system of ordinary differential equations (ODEs) using the similarity transformation. The obtained high non-linear system of equations has been solved numerically, using the parametric continuation method (PCM). In the present analysis, the main motivation is to highlight the heat transfer rate of MgO–Ag/water-based hybrid nanofluid flow over a Riga plate. The second motivation of the present research is to highlight the impact of slip conditions on the velocity, energy, and mass profiles. From the graphical analysis, it is depicted that the slip conditions reduce the velocity, energy, and mass outlines. From the present analysis, we concluded that volume friction reduced the flow profile while increasing the temperature of the fluid flow over a Riga plate. All the parameters of the present research are highlighted in velocity temperature and concertation of the fluid. In addition to this in all the figures we have compared the hybrid nanofluid with mono nanofluid and the also the comparison between slip and no-slip conditions have carried out through graphs for velocity, temperature, and concentration.
Curved veins and arteries make up the human cardiovascular system, and the peristalsis process underlies the blood flowing in these ducts. The blood flow in the presence of hybrid nanoparticles ...through a tapered complex wavy curved channel is numerically investigated. The behavior of the blood is characterized by the Casson fluid model while the physical properties of iron (Fe3O4) and copper (Cu) are used in the analysis. The fundamental laws of mass, momentum and energy give rise the system of nonlinear coupled partial differential equations which are normalized using the variables, and the resulting set of governing relations are simplified in view of a smaller Reynolds model approach. The numerical simulations are performed using the computational software Mathematica’s built-in ND scheme. It is noted that the velocity of the blood is abated by the nanoparticles’ concentration and assisted in the non-uniform channel core. Furthermore, the nanoparticles’ volume fraction and the dimensionless curvature of the channel reduce the temperature profile.
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The analysis of enhancing the heat transfer of a traditional fluid by adding nanoparticles was effectively studied by many researchers across the globe. In later stages, these ...nanofluids were made chemically stable by suspending an additional inert nanoparticle thus forming a hybrid nanofluid. The heat transfer characteristics of hybrid nanofluids are discussed in various aspects. Considering these studies, the heat and mass transfer characteristics of ternary nanofluid formed by suspending three different nanoparticles is analysed in this article. The self-propelled microorganisms move within the nanofluid due to the density gradient and it ensures proper mixing of nanoparticles. In order to achieve proper bioconvection caused by microorganisms, the nanoparticle concentration is assumed to be dilute and the fluid with these characteristics is assumed to flow as a jet past a stretching sheet. The mathematical model to analyse such a characteristic flow is framed using the modified Buongiorno’s model that describes the impact of volume fraction, thermophoresis and Brownian motion. The mathematical model obtained will be further converted into non-linear differential equations that are solved through the RKF-45 method. The results obtained through this method are interpreted graphically and the impact of fluid flow parameters on the heat and mass transfer rates are tabulated. It is perceived that the mixed convection parameter enhances the velocity profile. Similarly, the increase in the Brownian motion and thermophoresis enhances the thermal profile. Meanwhile, the increase in the nanoparticle volume fraction helps in enhancing the thermal conductivity and thus the temperature is found to be increasing.
The Internet of Things (IoT) era is mainly dependent on the word “Smart”, such as smart cities, smart homes, and smart cars. This aspect can be achieved through the merging of machine learning ...algorithms with IoT computing models. By adding the Artificial Intelligence (AI) algorithms to IoT, the result is the Cognitive IoT (CIoT). In the automotive industry, many researchers worked on self-diagnosis systems using deep learning, but most of them performed this process on the cloud due to the hardware limitations of the end-devices, and the devices obtain the decision via the cloud servers. Others worked with simple traditional algorithms of machine learning to solve these limitations of the processing capabilities of the end-devices. In this paper, a self-diagnosis smart device is introduced with fast responses and little overhead using the Multi-Layer Perceptron Neural Network (MLP-NN) as a deep learning technique. The MLP-NN learning stage is performed using a Tensorflow framework to generate an MLP model’s parameters. Then, the MLP-NN model is implemented using these model’s parameters on a low cost end-device such as ARM Cortex-M Series architecture. After implementing the MLP-NN model, the IoT implementation is built to publish the decision results. With the proposed implemented method for the smart device, the output decision based on sensors values can be taken by the IoT node itself without returning to the cloud. For comparison, another solution is proposed for the cloud-based architecture, where the MLP-NN model is implemented on Cloud. The results clarify a successful implemented MLP-NN model for little capabilities end-devices, where the smart device solution has a lower traffic and latency than the cloud-based solution.
Abstract
The current evaluation described the flow features of Darcy Forchhemier hybrid nanoliquid across a slender permeable stretching surface. The consequences of magnetic fields, second order ...exothermic reaction, Hall current and heat absorption and generation are all accounted to the fluid flow. In the working fluid, silicon dioxide (SiO
2
) and titanium dioxide (TiO
2
) nano particulates are dispersed to prepare the hybrid nanoliquid. TiO
2
and SiO
2
NPs are used for around 100 years in a vast number of diverse products. The modeled has been designed as a nonlinear set of PDEs, Which are degraded to the dimensionless system of ODEs by using the similarity transformation. The reduced set of nonlinear ODEs has been numerically estimated through bvp4c package. The outcomes are tested for validity and consistency purpose with the published report and the ND solve technique. It has been noted that the energy curve lessens with the influence of thermodiffusion, Brownian motion and rising number of nanoparticles, while boosts with the result of magnetic field. Furthermore, the concentration outline of hybrid nanoliquid improves with the upshot of chemical reaction.
This article presents a review of the interstitial microwave cancer ablation. Microwave cancer ablation is an effective technique for the cancer therapy using the electromagnetic radiations in the ...microwave range. The idea behind using the microwave electromagnetic radiations in cancer therapy is basically based on dielectric heating of the cancerous tissues until the death of the infected cells. This article reviews the theory of operation of the microwave cancer ablation technique with overview of the electrical properties of the biological tissues as they are key parameters to study the behavior of the cancer ablation process. Advantages of microwave cancer ablation technique over the other techniques especially its most related one, i.e., the radiofrequency cancer ablation are highlighted. Although the microwave cancer ablation has attained high attention by the researchers, many of challenges which degrade its performance still exist. The paper discusses the challenges of the microwave cancer ablation and highlights the efforts done by the researchers to tackle them. Different antenna structures utilized for microwave cancer ablation are presented with mention of their behavior, advantages and disadvantages. Moreover, some of the most recent progresses in the microwave cancer ablation field are presented.
Flow around circular cylinder has been extensively studied by researchers for several decades due to its wide range of engineering applications such as in heat exchangers, marine cables, high rise ...building, chimneys, and offshore structures. The lack of clear understanding of the unsteady flow dynamics in the wake of circular cylinder and high computational cost are still an area of high interest amongst the researchers. The aim of the current study is to investigate the effect of variation in spanwise length and grid resolution in the spanwise direction on the recirculation length, separation angle of wake flow by performing large eddy simulations (LES). This study is an extension to previous work by Khan, NB et al, 2019 in which the spanwise length is restricted to 4D only. In current study, the spanwise length is changed from 0.5D to 8D where D is diameter of cylinder and mesh resolution in the spanwise direction is changed from 1 to 80 elements in the present study. The recirculation length, separation angle and wake characteristics are analyzed in detail. It is concluded that after getting optimize spanwise length, mesh resolution in the spanwise direction is the only parameter contributing toward better result.
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