154 research outputs found

    Novel Color Image Compression Algorithm Based-On Quadtree

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    This paper presents a novel algorithm having two image processing systems that have the ability to compress the colour image. The proposed systems divides the colour image into RGB components, each component is selected to be divided. The division processes of the component into blocks are based on quad tree method. For each selection, the other two components are divided using the same blocks coordinates of the selected divided component. In the first system, every block has three minimum values and three difference values. While the other system, every block has three minimum values and one average difference. From experiments, it is found that the division according to the G component is the best giving good visual quality of the compressed images with appropriate compression ratios. It is also noticed, the performance of the second system is better than the first one. The obtained compression ratios ofthe second system are between 1.3379 and 5.0495 at threshold value 0.1, and between 2.3476 and 8.9713 at threshold value 0.2

    Suboptimal correction of low anorectal anomalies: a possible cause for intractable constipation in children

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    Background Constipation is a common problem among patients following the repair of low anorectal anomalies. We present our experience in managing constipation in a group of these patients with reoperation to correct residual anterior anal misplacement.Patients and methods The study included pediatric patients presenting with significant constipation following the repair of low anorectal anomalies. Patients with evidence of residual anterior anal misplacement (either clinically, by means of MRI, or using electrical muscle stimulation) were offered a reoperation to bring their ani backward to an orthotropic position.Results Thirteen patients were included in the study between September 2009 and June 2015. Their ages ranged from 1.5 to 10 years. The primary anomaly was rectoperineal fistula in 10 (seven boys and three girls) and rectovestibular in three girls. Two types of reoperations were performed: a posterior anoplasty with posterior sphincterotomy (five cases), and a limited sagittal anorectoplasty (eight cases). Straining at defecation was relieved in all patients. Of the 13 patients, nine were relieved from their constipation (69%) and had regular bowel movements without medications. The remaining four (31%) showed partial improvement.Conclusion Among patients with low anorectal anomalies, suboptimal correction with residual anterior anal misplacement represents one correctable cause for persistence of constipation

    COVID-19 Detection on Chest x-ray Images by Combining Histogram-oriented Gradient and Convolutional Neural Network Features

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    The COVID-19 coronavirus epidemic has spread rapidly worldwide after a person became infected with a severe health problem. The World Health Organization has declared the coronavirus a global threat (WHO). Early detection of COVID 19, particularly in cases with no apparent symptoms, may reduce the patients mortality rate. COVID 19 detection using machine learning techniques will aid healthcare systems around the world in recovering patients more rapidly. This disease is diagnosed using x-ray images of the chest; therefore, this study proposed a machine vision method for detecting COVID-19 in x-ray images of the chest. The histogram-oriented gradient (HOG) and convolutional neural network (CNN) features extracted from x-ray images were fused and classified using support vector machine (SVM) and softmax. The proposed feature fusion technique (99.36 percent) outperformed individual feature extraction methods such as HOG (87.34 percent) and CNN (93.64 percent)

    Prediction of Pressure Drop in Vertical Pneumatic Conveyors

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    This paper presents a steady state one-dimensional two-fluid model for gas-solid two-phase flow in a vertical riser. The model is solved using conservative variable approach for the gas phase, and fourth order Runge-Kutta method is used for the solid phase. The model predictions for pressure drop are compared with available experimental data and with Eulerian-Lagrangian predictions, and a good agreement is obtained. The results indicate that the pressure drop increases as the solid mass flow rate, particle size, and particles density increase. In addition, the model predictions for minimum pressure drop velocity are compared with experimental data from literature and the mean percentage error. MPE for minimum pressure drop velocity is -9.89%. It is found that the minimum pressure drop velocity increases as the solid mass flow, particle size and particle density increase, and decreases as the system total pressure increases

    Novel 1,3-Thiazole Analogues with Potent Activity against Breast Cancer: A Design, Synthesis, In Vitro, and In Silico Study

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    Breast cancer is the most common cancer in women, responsible for over half a million deaths in 2020. Almost 75% of FDA-approved drugs are mainly nitrogen- and sulfur-containing heterocyclic compounds, implying the importance of such compounds in drug discovery. Among heterocycles, thiazole-based heterocyclic compounds have demonstrated a broad range of pharmacological activities. In the present study, a novel set of 1,3-thiazole derivatives was designed and synthesized based on the coupling of acetophenone derivatives, and phenacyl bromide was substituted as a key reaction step. The activity of synthesized compounds was screened against the proliferation of two breast cancer cell lines (MCF-7 and MDA-MB-231). Almost all compounds exhibited a considerable antiproliferative activity toward the breast cancer cells as compared to staurosporine, with no significant cytotoxicity toward the epithelial cells. Among the synthesized compounds, compound 4 exhibited the most potent antiproliferative activity, with an IC50 of 5.73 and 12.15 ĀµM toward MCF-7 and MDA-MB-231 cells, respectively, compared to staurosporine (IC50 = 6.77 and 7.03 ĀµM, respectively). Exploring the mechanistic insights responsible for the antiproliferative activity of compound 4 revealed that compound 4 possesses a significant inhibitory activity toward the vascular endothelial growth factor receptor-2 (VEGFR-2) with (IC50 = 0.093 ĀµM) compared to Sorafenib (IC50 = 0.059 ĀµM). Further, compound 4 showed the ability to induce programmed cell death by triggering apoptosis and necrosis in MCF-7 cells and to induce cell cycle arrest on MCF-7 cells at the G1 stage while decreasing the cellular population in the G2/M phase. Finally, detailed in silico molecular docking studies affirmed that this class of compounds possesses a considerable binding affinity toward VEGFR2 proteins. Overall, these results indicate that compound 4 could be a promising lead compound for developing potent anti-breast cancer compounds.Faculty of Pharmacy, Suez Canal University, and Faculty of Science, Port Said University, EgyptPrincess Nourah bint Abdulrahman University Researchers SupportingTaif University Researcher

    Dietary supplementation of quercetin nanoparticles enhances the growth performance hematological and immunological responses and resistance to Aeromonas hydrophila infection in Nile tilapia (Oreochromis niloticus) exposed to silver nanoparticles toxicity

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    The wide incorporation of silver nanoparticles (AgNPs) in aquaculture could result in releasing of these particles into the environment with environmental impacts and health hazards. Thus, this study aimed to investigate the impacts of the dietary supplementation of quercetin nanoparticles (QNPs) on Nile tilapia (Oreochromis niloticus) growth, antioxidants, and immunity besides its susceptibility to the infection with Aeromonas hydrophila with or without the aqueous exposure to AgNPs. First, the 96-h LC50 value for AgNPs in O. niloticus wa estimated to be 19.81 mg/L (the 1/10th of the 96 h LC50 of AgNPs = 1.98 mg/L). Then a total of 240 Nile tilapias (40.00 Ā± 0.45 g) were randomly distributed into 4 groups (each group contains 60 fish in 3 replicates of 20 fish). The 1st group (control) was fed on a basal diet without QNPs and AgNPs. The 2nd group (QNPs) received the basal diet supplemented with QNPs (400 mg/kg), the 3rd group (AgNPs) was exposed to 1/10th 96-h LC50 of AgNPs (1.98 mg/L) and fed on QNPs free diet, while the 4th group (AgNPs+ QNPs) was exposed to AgNPs (1.98 mg/L) and cosupplemented with QNPs (400 mg/kg). Besides, AgNPs resulted in marked elevation in the serum myeloperoxidase (MPO) 8-hydroxy-2-deoxyguanosine (8-OHdG) contents, and declines in lysozyme activity and the levels of nitric oxide (NO) and immunoglobulins (IgM and IgG) in the exposed fish (AgNPs group). These effects were accompanied with significant downregulation in the relative mRNA expressions of SOD, CAT, and GSH and upregulation in the expressions of INF-Ī³, TNF-Ī±, and Il-1Ī². Feeding QNPs-enriched diet, alone or combined with AgNPs exposure, conversed most of these effects and restored some to the control levels. AgNPs exposure increased mortalities, lowered survival rates and altered Nile tilapiaā€™s resistance to A. hydrophila infection in the AgNPs exposed fish, whereas co-supplementation with QNPs enhanced their resistance with less mortalities. In summary, the reported immunomodulation, and protective properties of QNPs dietary supplementation, strengthen its applicability as an effective and promising feed supplement to alleviate the AgNPs associated toxicity in fish

    NUMERICAL INVESTAGATION OF GAS-SOLID SUSPENSION FLOW IN 180 o CURVED DUCT

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    ABSTRACT In this paper, a two-way coupling EulerianLagrangian approach is presented for the simulation of gassolid two-phase flow in 180 o curved duct. In the present study, Reynolds averaged Navier-Stokes equations (RANS) and two turbulence models namely; standard k-Īµ model and RNG (Renormalization Group) based k-Īµ model are adopted. The effects of particle rotation and lift forces are included in the particle tracking model while the effect of inter-particle collisions is neglected. The present predictions are compared with published experimental data for single-phase flow and published particles trajectories. The comparisons show that the RNG based k-Īµ model predicts the flow behaviour better than the standard k-Īµ model. Furthermore, the particles trajectories are compared very well with published data. The effects of inlet gas velocity, bend geometry, loading ratio and solid properties on the flow behaviour are also discussed. The results show that the flow behaviour is greatly affected by the above parameters

    The ligational behavior of a phenolic quinolyl hydrazone towards copper(II)- ions

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    <p>Abstract</p> <p>Background</p> <p>The heterocyclic hydrazones constitute an important class of biologically active drug molecules. The hydrazones have also been used as herbicides, insecticides, nematocides, redenticides, and plant growth regulators as well as plasticizers and stabilizers for polymers. The importance of the phenolic quinolyl hydrazones arises from incorporating the quinoline ring with the phenolic compound; 2,4-dihydroxy benzaldehyde. Quinoline ring has therapeutic and biological activities whereas, phenols have antiseptic and disinfectants activities and are used in the preparation of dyes, bakelite and drugs. The present study is planned to check the effect of the counter anions on the type and geometry of the isolated copper(II)- complexes as well as the ligational behavior of the phenolic hydrazone; 4-[(2-(4,8-dimethylquinolin-2-yl)hydrazono)methyl] benzene-1,3-diol; (H<sub>2</sub>L).</p> <p>Results</p> <p>A phenolic quinolyl hydrazone (H<sub>2</sub>L) was allowed to react with various copper(II)- salts (Clā€¾, Brā€¾, NO<sub>3</sub>ā€¾, ClO<sub>4</sub>ā€¾, AcOā€¾, SO<sub>4</sub><sup>2-</sup>). The reactions afforded dimeric complexes (ClO<sub>4</sub>ā€¾, AcOā€¾ ), a binuclear complex (NO<sub>3</sub>ā€¾ ) and mononuclear complexes (the others; Clā€¾, Brā€¾, SO<sub>4</sub><sup>2-</sup>). The isolated copper(II)- complexes have octahedral, square pyramid and square planar geometries. Also, they reflect the strong coordinating ability of NO<sub>3</sub>ā€¾, Clā€¾, Brā€¾, AcOā€¾ and SO<sub>4</sub><sup>2- </sup>anions. Depending on the type of the anion, the ligand showed three different modes of bonding <it>viz</it>. (NN)<sup>0 </sup>for the mononuclear complexes (<b>3, 4, 6</b>), (NO)<sup>- </sup>with O- bridging for the dimeric complexes (<b>1, 5</b>) and a mixed mode [(NN)<sup>0 </sup>+ (NO)<sup>- </sup>with O- bridging] for the binuclear nitrato- complex (<b>2</b>).</p> <p>Conclusion</p> <p>The ligational behavior of the phenolic hydrazone (H<sub>2</sub>L) is highly affected by the type of the anion. The isolated copper(II)- complexes reflect the strong coordinating power of the SO<sub>4</sub><sup>2-</sup>, AcOā€¾, Brā€¾, Clā€¾ and NO<sub>3</sub>ā€¾ anions. Also, they reflect the structural diversity (octahedral, square pyramid and square planar) depending on the type of the counter anion.</p

    Ligand substitution reactions of a phenolic quinolyl hydrazone; oxidovanadium (IV) complexes

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    <p>Abstract</p> <p>Background</p> <p>Quinoline ring has therapeutic and biological activities. Quinolyl hydrazones constitute a class of excellent chelating agents. Recently, the physiological and biological activities of quinolyl hydrazones arise from their tendency to form metal chelates with transition metal ions. In this context, we have aimed to study the competency effect of a phenolic quinolyl hydrazone (H<sub>2</sub>L; primary ligand) with some auxiliary ligands (Tmen, Phen or Oxine; secondary ligands) towards oxidovanadium (IV) ions.</p> <p>Results</p> <p>Mono- and binuclear oxidovanadium (IV) - complexes were obtained from the reaction of a phenolic quinolyl hydrazone with oxidovanadium (IV)- ion in absence and presence of N,N,N',N'- tetramethylethylenediamine (Tmen), 1,10-phenanthroline (Phen) or 8-hydroxyquinoline (Oxine). The phenolic quinolyl hydrazone ligand behaves as monobasic bidentate (NO- donor with O- bridging). All the obtained complexes have the preferable octahedral geometry except the oxinato complex (<b>2</b>) which has a square pyramid geometry with no axial interaction; the only homoleptic complex in this study.</p> <p>Conclusion</p> <p>The ligand exchange (substitution/replacement) reactions reflect the strong competency power of the auxiliary aromatic ligands (Phen/Oxine) compared to the phenolic quinolyl hydrazone (H<sub>2</sub>L) towards oxidovanadium (IV) ion; (complexes <b>2 </b>and <b>3</b>). By contrast, in case of the more flexible aliphatic competitor (Tmen), an adduct was obtained (<b>4</b>). The obtained complexes reflect the strength of the ligand field towards the oxidovanadium (IV)- ion; Oxine or Phen >> phenolic hydrazone (H<sub>2</sub>L) > Tmen.</p
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