1,061 research outputs found
Conjunctivitis: A Systematic Review
Conjunctivitis is a commonly encountered condition in ophthalmology clinics throughout the world. In the management of suspected cases of conjunctivitis, alarming signs for more serious intraocular conditions, such as severe pain, decreased vision, and painful pupillary reaction, must be considered. Additionally, a thorough medical and ophthalmic history should be obtained and a thorough physical examination should be done in patients with atypical findings and chronic course. Concurrent physical exam findings with relevant history may reveal the presence of a systemic condition with involvement of the conjunctiva. Viral conjunctivitis remains to be the most common overall cause of conjunctivitis. Bacterial conjunctivitis is encountered less frequently and it is the second most common cause of infectious conjunctivitis. Allergic conjunctivitis is encountered in nearly half of the population and the findings include itching, mucoid discharge, chemosis, and eyelid edema. Long-term usage of eye drops with preservatives in a patient with conjunctival irritation and discharge points to the toxic conjunctivitis as the underlying etiology. Effective management of conjunctivitis includes timely diagnosis, appropriate differentiation of the various etiologies, and appropriate treatment
Rapid and efficient ultrasonic assisted adsorption of diethyl phthalate onto FeIIFe2 IIIO4@GO: ANN-GA and RSM-DF modeling, isotherm, kinetic and mechanism study
Herein, an ultrasonic assisted dispersive magnetic solid-phase adsorption method along with a high-performance liquid chromatography system for the diethyl phthalate (DEP) removal was developed. In this regard, magnetic iron oxide/graphene oxide (MGO) nanocomposites were prepared by a simple and effective chemical co-precipitation method, followed by nucleation and growth of nanoparticles. The structure and morphology of MGO was identified by Transmission electron microscopy (TEM), Scanning electron microscopy (SEM), Energy dispersive X-ray (EDX) spectroscopy X-ray diffraction (XRD), Vibrating sample magnetometer (VSM), Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS) and N2 adsorption-desorption techniques. The interactive and main effect of parameters such as pH, adsorbent dosage, sonication time and concentration of DEP involved in the adsorption process were set within the ranges 3.0�11.0, 0.10�0.50 g L�1, 1�5 min, 5�10 mg/L, respectively. Root means square error (RMSE), mean absolute error (MAE), absolute average deviation (AAD), and coefficient of determination (R2) was employed to examine the applicability of the response surface methodology (RSM) and artificial neural network (ANN) models for the description of experimental data. Compared to RSM, the ANN showed a more accurate performance for modeling the process of DEP adsorption. Using genetic algorithm-ANN, optimum conditions were set to 5.38, 334.7 mg/L, 3.723 min and 4.21 mg/L for pH, adsorbent dose, sonication time and concentration of DEP, respectively. Under the optimized conditions, the maximum adsorption capacity and adsorption factors were 116.933 mg/g and 100, respectively, while the relative standard deviations (RSDs) was <1.6 (N = 5). The isotherm models display that the Langmuir has the best fit with the equilibrium data, and adsorption kinetics followed the pseudo-second-order model. The thermodynamic results confirmed that the sorption was endothermic and occurred spontaneously. The results exhibited that MGO has excellent potential as an adsorbent for the removal of phthalates from the contaminated water. © 2019 Elsevier B.V
Traumatic Endothelial Corneal Rings
This is a Photo Essay. Please download the PDF or view the article HTML
Adsorption and magnetic separation of lead from synthetic wastewater using carbon/iron oxide nanoparticles composite
Background and purpose: Removal of lead as a toxic metal from contaminated water resources is necessary due to the dangerous effect of lead. One of the most effective methods of removal is the adsorption process. The aim of this study was adsorption and magnetic separation of lead from synthetic wastewater using iron oxide nanoparticles and carbon (ION/C) composite Material and Methods: In this study nanoparticles of iron oxide (ION) were used as a source of iron for magnetic separation of powder activated carbon from solution samples. The physical and surface properties of the adsorbent were studied along with influencing factors (pH, contact time, adsorbent dosage, initial lead concentration, and temperature) on the adsorption process. Kinetic equations and equilibrium isotherms studies were also conducted. Results: The size of ION and specific surface area of ION/C were found to be 30-80 nm and 671.2 m2/g, respectively. We observed that the adsorption process reached equilibrium at 60 min and pH=6and adsorption efficiency increased by increasing the amount of adsorbent and temperature. Maximum adsorption capacity based on Langmuir isotherms was obtained 67.1mg/g at 50 °C. Conclusion: According to this study it is believed that magnetized active carbon by keeping its physical and surface properties could be a suitable method to solve some related problems including separation and filtration
Management of COVID-19 myopericarditis with reversal of cardiac dysfunction after blunting of cytokine storm: a case report.
Background:Coronavirus disease 2019 (COVID-19) is a syndrome that has been associated with multiple cardiac complications including myopericarditis. The pathophysiology and treatment for myopericarditis in the setting of COVID-19 infection is still under investigation. Case summary:We present a case of a 60-year-old male admitted for dyspnoea due to COVID-19. He developed new ST-segment elevation, elevated cardiac enzymes, severe left ventricular dysfunction, and high inflammatory markers in the setting of haemodynamic and respiratory collapse from the viral illness. He was diagnosed with COVID-19-induced myopericarditis. He showed rapid clinical improvement with a rapid wean off pressure support, resolution of electrocardiogram (ECG) findings, and recovery of left ventricular systolic function following treatment with intravenous immunoglobulin (IVIG) and methylprednisolone. Discussion:COVID-19\u27s complex and devastating complications continue to create new challenges for clinicians. Cardiac complications, specifically, have been shown to be a signal for worse prognosis in these patients. IVIG and steroids can inhibit the inflammatory cascade and decrease myocardial injury, with implications in treatment of severe myopericarditis
On the edge-Wiener index of the disjunctive product of simple graphs
The edge-Wiener index of a simple connected graph G is defined as the sum of distances between all pairs of edges of G where the distance between two edges in G is the distance between the corresponding vertices in the line graph of G. In this paper, we study the edge-Wiener index under the disjunctive product of graphs and apply our results to compute the edge-Wiener index for the disjunctive product of paths and cycles
Incorporating Physical Knowledge into Machine Learning for Planetary Space Physics
Recent improvements in data collection volume from planetary and space
physics missions have allowed the application of novel data science techniques.
The Cassini mission for example collected over 600 gigabytes of scientific data
from 2004 to 2017. This represents a surge of data on the Saturn system.
Machine learning can help scientists work with data on this larger scale.
Unlike many applications of machine learning, a primary use in planetary space
physics applications is to infer behavior about the system itself. This raises
three concerns: first, the performance of the machine learning model, second,
the need for interpretable applications to answer scientific questions, and
third, how characteristics of spacecraft data change these applications. In
comparison to these concerns, uses of black box or un-interpretable machine
learning methods tend toward evaluations of performance only either ignoring
the underlying physical process or, less often, providing misleading
explanations for it. We build off a previous effort applying a semi-supervised
physics-based classification of plasma instabilities in Saturn's magnetosphere.
We then use this previous effort in comparison to other machine learning
classifiers with varying data size access, and physical information access. We
show that incorporating knowledge of these orbiting spacecraft data
characteristics improves the performance and interpretability of machine
learning methods, which is essential for deriving scientific meaning. Building
on these findings, we present a framework on incorporating physics knowledge
into machine learning problems targeting semi-supervised classification for
space physics data in planetary environments. These findings present a path
forward for incorporating physical knowledge into space physics and planetary
mission data analyses for scientific discovery.Comment: 25 pages, 7 figures, accepted for publication in Frontiers in
Astronomy and Space Sciences for the Research Topic of Machine Learning in
Heliophysics at https://www.frontiersin.org/articles/10.3389/fspas.2020.0003
A novel, eco-friendly and green synthesis of PPAC-ZnO and PPAC-nZVI nanocomposite using pomegranate peel: Cephalexin adsorption experiments, mechanisms, isotherms and kinetics
In the present work, powdered activated carbon coated by nanoparticles ZnO and nZVI was derived from pomegranate peel extracts and finally applied for removal of cephalexin (CEX (from aqueous solutions. This experimental research was conducted discontinuously. The effects of pH of solution, reaction time, PPAC-nZVI and PPAC-ZnO composites dose, and initial concentration of cephalexin and composite recovery on process efficiency were investigated. The removal efficiency in optimal conditions for cephalexin with PPAC-nZVI and PPAC-ZnO (CEX = 50 mg L�1, composite dose = 1.25 g L�1, reaction time = 45 min and pH = 5) was obtained 96.06 and 94.17, respectively. The results of the study of isotherm and absorption kinetics for both composites showed that the absorption process follows Langmuir isotherm and pseudo second-order kinetics. The present study showed that the composites could be used as an effective and bio-friendly absorbent to remove cephalexin from aqueous solutions. © 2020 The Society of Powder Technology Japa
Iron-silver oxide nanoadsorbent synthesized by co-precipitation process for fluoride removal from aqueous solution and its adsorption mechanism
Fe-Ag magnetic binary oxide nanoparticles (Fe-Ag MBON) are prepared with co-precipitation of ferric and ferrous chloride solutions, and used for the adsorption of fluoride from aqueous solution. The surface morphology of the adsorbent was characterized by XRD, SEM, TEM, FTIR, XPS, EDX, BET, DLS and VSM techniques. Batch method was followed to optimize the conditions for the removal of fluoride. The results showed maximum removal occurred at pH 3.0 and adsorption equilibrium was achieved within 20 min. Chemical kinetics of the adsorption were well fitted by pseudo-second order models (R2 > 0.968) and the adsorption process followed the Langmuir isotherm model well (R2 > 0.976). The fluoride adsorption capacity of Fe-Ag MBON was 22.883 mg g-1, and decreased with increasing the temperature. Thermodynamic values revealed that the fluoride adsorption process was spontaneous and exothermic. Regeneration experiments were carried out for six cycles and the results indicate a removal efficiency loss of <22. © 2015 The Royal Society of Chemistry
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