946 research outputs found
Initial sintering stage kinetics of CeO<sub>2</sub> studied by stepwise isothermal dilatometry
Treatment results and prognostic factors of pediatric neuroblastoma: a retrospective study
<p>Abstract</p> <p>Background</p> <p>We conducted a retrospective analysis to investigate treatment results and prognostic factors of pediatric neuroblastoma patients.</p> <p>Methods</p> <p>This retrospective study was carried out analyzing the medical records of patients with the pathological diagnosis of neuroblastoma seen at South Egypt Cancer Institute, Assiut University during the period from January 2001 and January 2010. After induction chemotherapy, response according to international neuoblastoma response criteria was assessed. Radiotherapy to patients with residual primary tumor was applied. Overall and event free survival (OAS and EFS) rates were estimated using Graphed prism program. The Log-rank test was used to examine differences in OAS and EFS rates. Cox-regression multivariate analysis was done to determine the independent prognostic factors affecting survival rates.</p> <p>Results</p> <p>Fifty three cases were analyzed. The median follow-up duration was 32 months and ranged from 2 to 84 months. The 3-year OAS and EFS rates were 39.4% and 29.3% respectively. Poor prognostic factors included age >1 year of age, N-MYC amplification, and high risk group. The majority of patients (68%) presented in high risk group, where treatment outcome was poor, as only 21% of patients survived for 3 year.</p> <p>Conclusion</p> <p>Multivariate analysis confirmed only the association between survival and risk group. However, in univariate analysis, local radiation therapy resulted in significant survival improvement. Therefore, radiotherapy should be given to patients with residual tumor evident after induction chemotherapy and surgery. Future attempts to improve OAS in high risk group patients with aggressive chemotherapy and bone marrow transplantation should be considered.</p
Evaluation of two freshwater macrophytes, Ceratophyllum demersum and Potamogeton amplifoliusas feed ingredients for Nile tilapia (Oreochromis niloticus) fingerlings
The present study was carried out to evaluate the potential of two common freshwater macrophytes (Ceratophyllum demersum and Potamogeton amplifolius) as feed ingredients for Nile tilapia fingerlings, in two consecutive experiments. The first experiment investigated the use of raw, dried C. demersum and P. amplifolius as sources of energy in the diets of fingerlings. The macrophytes were incorporated in 6 isonitrogenous and isocaloric diets at four levels as a replacement of dietary wheat bran. The test diets were fed to triplicate groups, stocked in 140 L culture aquaria in a recirculating system, three times a day to satiation, for 45 days. The results showed that control, macrophyte-free diet produced significantly improved growth rates and feed utilization efficiency than macrophytes-based diets. In Experiment 2, fermented C. demersum and P. amplifolius were incorporated into six isonitrogenous and isocaloric diets. The diets were fed to triplicate groups of fingerlings (35 g) for 45 days. Growth rates and feed utilization efficiency of fish fed with fermented P. amplifolius at 33 % and 66 % inclusion level were not significantly different from fish fed the control diet. At 100 % inclusion level, fish performance was significantly reduced. On the other hand, fermented C. demersum produced extremely poor performance, compared to raw ceratophyllum. In conclusion, the present results indicated that fermentation improved the quality of P. amplifolius; but not C. demersum
Evaluation of two freshwater macrophytes, Ceratophyllum demersum and Potamogeton amplifoliusas feed ingredients for Nile tilapia (Oreochromis niloticus) fingerlings
37-43The present study was carried out to evaluate the potential of two common freshwater macrophytes (Ceratophyllum demersum and Potamogeton amplifolius) as feed ingredients for Nile tilapia fingerlings, in two consecutive experiments. The first experiment investigated the use of raw, dried C. demersum and P. amplifolius as sources of energy in the diets of fingerlings. The macrophytes were incorporated in 6 isonitrogenous and isocaloric diets at four levels as a replacement of dietary wheat bran. The test diets were fed to triplicate groups, stocked in 140 L culture aquaria in a recirculating system, three times a day to satiation, for 45 days. The results showed that control, macrophyte-free diet produced significantly improved growth rates and feed utilization efficiency than macrophytes-based diets.
In Experiment 2, fermented C. demersum and P. amplifolius were incorporated into six isonitrogenous and isocaloric diets. The diets were fed to triplicate groups of fingerlings (35 g) for 45 days. Growth rates and feed utilization efficiency of fish fed with fermented P. amplifolius at 33 % and 66 % inclusion level were not significantly different from fish fed the control diet. At 100 % inclusion level, fish performance was significantly reduced. On the other hand, fermented C. demersum produced extremely poor performance, compared to raw ceratophyllum. In conclusion, the present results indicated that fermentation improved the quality of P. amplifolius; but not C. demersum
Influence of some industrial wastes as a heavy aggregate on durability of concrete upon utilization in the special constructions
The aim of this study is to investigate the effect of some industrial wastes as a heavy aggregate on durability of the concrete after exposure to different effects. The coarse aggregates used to perform the concrete were dolomite (control) and lead slag, while fine aggregate were sand and lead slag aggregate. The physical and mechanical properties of use draw aggregates were determined also the physical and mechanical properties of different types of concrete were studied. The linear attenuation coefficients (ÎĽ) and half value layer (HVL) of gamma rays measurements have been carried out using Îł-rays sources of Cs173 and Co60. Effect of sea water on the mechanical properties of high performance concrete; in addition, corrosion behavior of reinforcing steel embedded in concrete incorporating different aggregates upon exposure to sea water were studied. It was found that, the compressive strength for all concrete mixes made with dolomite and lead slag coarse aggregates satisfy the requirements of compressive strength for high performance concrete (grade-M60) after 28 days of curing in tap water. The results indicate that, the compressive strength values and gamma radiation shielding properties of concrete mix containing lead slag aggregate enhances upon replacing sand by fine portion of lead slag aggregate. The concrete mixes made with lead slag coarse aggregate proved their high endurance and could sustain sea water exposure, achieving compressive strength values exceeding grade M-60 concrete even after 6 months exposure. Lead slag concrete- in spite of its efficient durability-requires the incorporation of a corrosion inhibitor to counteract the hostile effect of the high sulfate concrete in the aggregate
Brain Tumor Classification Using Hybrid Single Image Super-Resolution Technique with ResNext101_32x8d and VGG19 Pre-Trained Models
High-quality images acquired from medical devices can be utilized to aid diagnosis and detection of various diseases. However, such images can be very expensive to acquire and difficult to store, and the process of diagnosis can consume significant time. Automatic diagnosis based on artificial intelligence (AI) techniques can contribute significantly to overcoming the cost and time issues. Pre-trained deep learning models can present an effective solution to medical image classification. In this paper, we propose two such models, ResNext101_ 32Ă—8d and VGG19 to classify two types of brain tumor: pituitary and glioma The proposed models are applied to a dataset consisting of 1,800 MRI images comprising in two classes of diagnoses; glioma tumor and pituitary tumor. A single-image super-resolution (SISR) technique is applied to the MRI images to classify and enhance their basic features, enabling the proposed models to enhance particular aspects of the MRI images and assist the training process of the models. These models are implemented using PyTorch and TensorFlow frameworks with hyper-parameter tuning, and data augmentation. Experimentally, receiver operating characteristic curve (ROCC), the error matrix, Precision, and Recall are used to analyze the performance of the proposed model. Results obtained demonstrate that VGG19 and ResNext101_ 32Ă—8d achieved testing accuracies of 99.98% and 100%, and loss rates of 0.0120 and 0.108, respectively. The F1-score, Precision, Recall, and the area under the ROC for VGG19 were 99.89%, 99.90%, 99.89%, and 100%, respectively, while for the ResNext101_ 32Ă—8d they were all 100%. The proposed models when applied to MRI images to provide a quick and accurate approach to distinguishing between patients with pituitary and glioma tumors, and could aid doctors and radiologists in the screening of patients with brain tumors
Fuel cell as an effective energy storage in reverse osmosis desalination plant powered by photovoltaic system
A hybrid renewable energy systems (HRESs) comprises of photovoltaic (PV), and self-charging fuel cells (SCFC) is designed for securing electrical energy required to operate brackish water pumping (BWP) and reverse osmosis desalination (RO) plant of 150 m3 d-1 for irrigation purposes in remote areas. An optimal configuration of the proposed design is determined based on minimum cost of energy (COE) and the minimum total net present cost (NPC). Moreover, a comparison with a stand-alone diesel generation (DG) or grid extension is carried out against the optimal configuration of PV/SCFC HRES. The modeling, simulation, and techno-economic evaluation of the different proposed systems, including the PV/SCFC system are done using HOMER software. Results show that PV array (66 kW), FC (9 kW), converter (25 KW) –Electrolyzer (15 kW), Hydrogen cylinder (70 kg) are the viable economic option with a total NPC of 0.062 unit cost of electricity. The COE for the stand-alone DG system is 0.206 $/kWh, which is 69.90% higher than that of the PV/SCFC system. The PV/SCFC system is cheaper than grid extension. This study opens the way for using a fuel cell as an effective method for solving the energy intermittence/storage problems of renewable energy sources
New Algorithm for Drawings of 3-Planar Graphs
Graphs arise in a natural way in many applications, together with the need to be drawn. Except for very small instances, drawing a graph by hand becomes a very complex task, which must be performed by automatic tools. The field of graph drawing is concerned with finding algorithms to draw graph in an aesthetically pleasant way, based upon a certain number of aesthetic criteria that define what a good drawing, (synonyms: diagrams, pictures, layouts), of a graph should be. This problem can be found in many such as in the computer networks, data networks, class inter-relationship diagrams in object oriented databases and object oriented programs, visual programming interfaces, database design systems, software engineering…etc. Given a plane graph G, we wish to find a drawing of G in the plane such that the vertices of G are represented as grid points, and the edges are represented as straight-line segments between their endpoints without any edge-intersection. Such drawings are called planar straight-line drawings of G. An additional objective is to minimize the area of the rectangular grid in which G is drawn. In this paper we introduce a new algorithms that finds an embedding of 3-planar graph. Keywords: 3- Planar Graph; Graph Drawing; drawing on grid
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