Polynomial Inverse Integrating Factors, First Integral and Non-Existence of Limit Cycles in the Plane for Quadratic Systems

The main purpose of this paper is to study the existence of polynomial inverse integrating factor and first integral, and non-existence of limit cycles for all systems. Furthermore, we consider some applications

SPECTRAL STUDIES AND ANTIMICROBIAL SCREENING FOR SOME NOVEL CHALCONES ANALOGUES

Objective: The present work aim to study the spectral and antimicrobial activity for synthesized chalcones Methods: The synthesized Chalcones were characterized by Physical and spectral methods such as melting point, IR, 1H-NMR and Mass analysis. The synthesized compounds have been screened for their antimicrobial activity. Results: The biological data showed that compounds III, VII had strong activities against the Staphylococcus aureus, Bacillus subtilis, and Pseudomonas aeruginosa, but not activity against fungus. Conclusion: The main purpose to use an easy and useful method to synthesize biologically active chalcone

Fracture Resistance of computer aided endo-crowns versus conventional endo-supported computer aided full crowns

The purpose of the present study was to investigate the fracture resistance of computer aided endo-crowns versus conventional core-supported computer aided full crowns. Ninety human teeth were collected, 30 for each type (maxillary central incisors, maxillary 1st premolars and maxillary 1st molars). Specimens were divided into 3 groups (n=10) according to restoration used: 1) PC: Post-core and crown; 2) NC: Nayyar core and crown and 3) EC: Endo-crown. Each group was further subdivided into 3 subgroups according to the tooth used: I (Incisor), P (Premolar) and M (Molar). For group PC: Fiber post (Radix, Dentsply Maillefer) were cemented using resin cement (Calibra Dual Cure, Denstply Detrey GmbH). For group NC: 3 mm of gutta percha of every canal was removed. For groups PC and NC, after etching and bonding of root-face, transparent core former (Coltène/ Whaledent) was filled with SDR (Smart Dentine Replacement, Dentsply Detrey GmbH) and inverted onto root-face and cured. All specimens were individually scanned and thermocycled for 1000 cycles then submitted to compression test using universal testing machine (Instron 8874; Instron Corp.) Fracture was confirmed by sudden drop in load readings. Subgroup IPC scored the highest mean among group I and subgroup PNC scored the highest mean among group P. One-Way ANOVA detected significant differences among groups I and M with p\u3c 0.05 in I and M groups. Regarding P group, P-value was \u3e 0.05 indicating no significant differences among group. Endocrown showed the highest fracture resistance means in molars, while Nayyar core and crown showed the highest fracture resistance means in premolars. However, post-core and crown revealed the highest fracture resistance means in incisors

EVALUATION OF AN EXPERIMENTAL SCREW-RETAINED RETRIEVABLE CROWN VERSUS CONVENTIONAL CROWN DESIGN

Statement of problem: Removing cemented crowns is usually a complicated procedure that may lead to irreversible damage to the tooth/crown and mostly necessitate remake of crown with added effort for both patient and clinician. Purpose: This in-vitro study evaluated an experimental two-component, screw-retained retrievable crown design in comparison to the conventional design. Materials and methods: A total of 120 extracted maxillary 2nd premolars received root canal treatment and were divided into two groups (n=60 each) according to the crown design they will receive. Gp CC received a threaded modified post, a composite core and a metal coping, while Gp RC received a two-component retrievable crown design. Fracture resistance was assessed by a 90 degrees vertical load to the center of the occlusal surface, using universal testing machine, under a constant crosshead speed of 0.5 mm/min until failure. Microleakage was assessed by placing specimens in methylene blue dye for 12 hours, sectioning the teeth longitudinally, and then examining the sectioned samples under stereomicroscope. Retrievability testing was conducted by 5 prosthodontists who attempted to uncover and unscrew the posts. Data were statistically evaluated using computer software (SPSS version 17; SPSS Inc.). Results: No significant difference between the 2 designs tested regarding microleakage tests (P=.34) whereas the experimental design, was significantly more resistant to fracture and more retrievable than the conventional one (P\u3e.5). Conclusions: The proposed retrievable crown design showed promising results and may be considered as an option to substitute the conventional design. Further studies are needed to confirm that

High-Throughput Sequencing and Metagenomic Data Analysis

Metagenomic approaches are a growing branch of science and have many applications in different fields. Metagenomics seems to be the ideal culture-independent technique for unraveling the biodiversity of soils and to study how this biodiversity is affected with continuously changing conditions. In addition, its application in clinical and diagnostic approaches was reported. The emergence of several next-generation sequencing (NGS) strategies enriched the metagenomics. The combination between NGS and metagenomic approaches helped the investigators resolve several issues regarding the microbial diversity and the functions and relationships among different microbial flora. A number of NGS approaches were developed including Roche/454 pyrosequencing, Illumina/Solexa sequencing, and Applied Biosystems/SOLiD sequencing. In this chapter, different NGS platforms are discussed in terms of principle, advantages, and limitations. In addition, third-generation sequencing technologies are also addressed

Organic and Inorganic Salts as Postharvest Alternative Control Means of Citrus

Several postharvest disease control means alternative to conventional chemical fungicides, such as organic and inorganic salts, will be highlighted in the proposed chapter. In particular, it will comprehensively cover different aspects of the use of salts against postharvest Penicillium decay of citrus. It will be an essential resource for the graduate and postgraduate students, researchers, professionals, supply chain players, citrus industries, and retailers. Organic and inorganic salts have a broad spectrum of activity against a wide range of fungi. In addition, they are easy to apply, inexpensive, safe for humans and the environment, and suitable for commercial postharvest handling practices. Different application strategies of salts, before and after harvest, and combined application (with wax, natural compounds, and fungicides, etc.) will be also discussed. The present chapter attempts to highlight how the use of organic and inorganic salts as alternative postharvest disease management technologies has developed from the laboratory to the market

On the Assessment of Surface Quality and Productivity Aspects in Precision Hard Turning of AISI 4340 Steel Alloy: Relative Performance of Wiper vs. Conventional Inserts

This article reports an experimental assessment of surface quality generated in the precision turning of AISI 4340 steel alloy using conventional round and wiper nose inserts for different cutting conditions. A three-factor (each at 4 levels) full factorial design of experiment was followed for feed rate, cutting speed, and depth of cut, with resulting machined surface quality characterized by resulting average roughness (Ra). The results show that, for the provided range of cutting conditions, lower surface roughness values were obtained using wiper inserts compared with conventional inserts, indicating a superior performance. When including the type of insert as a qualitative factor, ANOVA revealed that the type of insert was most important in determining surface roughness and material removal rate, with feed rate as the second most significant, followed by the interaction of feed rate and type of insert. It was found that using wiper inserts allowed simultaneous increases in feed rate, cutting speed, and depth of cut, while providing better surface quality of lower Ra, compared to the global minimum value that could be achieved using the conventional insert. These findings show that wiper inserts produce better surface quality and a material removal rate up to ten times higher than that obtained with conventional inserts. This clearly indicates the tremendous advantages of high surface quality and productivity that wiper inserts can offer when compared with the conventional round nose type in precision hard turning of AISI 4340 alloy steel

Short Text Semantic Similarity Measurement Approach Based on Semantic Network

Estimating the semantic similarity between short texts plays an increasingly prominent role in many fields related to text mining and natural language processing applications, especially with the large increase in the volume of textual data that is produced daily. Traditional approaches for calculating the degree of similarity between two texts, based on the words they share, do not perform well with short texts because two similar texts may be written in different terms by employing synonyms. As a result, short texts should be semantically compared. In this paper, a semantic similarity measurement method between texts is presented which combines knowledge-based and corpus-based semantic information to build a semantic network that represents the relationship between the compared texts and extracts the degree of similarity between them. Representing a text as a semantic network is the best knowledge representation that comes close to the human mind's understanding of the texts, where the semantic network reflects the sentence's semantic, syntactical, and structural knowledge. The network representation is a visual representation of knowledge objects, their qualities, and their relationships. WordNet lexical database has been used as a knowledge-based source while the GloVe pre-trained word embedding vectors have been used as a corpus-based source. The proposed method was tested using three different datasets, DSCS, SICK, and MOHLER datasets. A good result has been obtained in terms of RMSE and MAE

Effect of Atorvastatin And Garlic on Lipid Profile in Hyperlipidemic Patients

Background: Hyperlipidemia is one of the most common diseases among Iraqi community, and using herbal medicine in treating hyperlipidemia was a good choice to reduce the side effect of recommended drugs with good results of healing, Garlic (Allium sativum) has been used in herbal medicine for centuries for various health problems. It has a beneficial effect of reducing serum lipids and cardiovascular system disease .The purpose of present study was to evaluate the effects of garlic and atorvastatine on the dyslipidemic people. Aim: The aim of this study is to assist the affectivity of the garlic in lowering the lipid profile in hyperlipidemic patients as well as the effect of time on treatment. Methods: This 12 week, Garlic treated, atorvastatin, Garlic + atorvastatin and non-treated study was conducted on patients with hyperlipidemia (n=40) were divided into 4 groups each comprising 10 patients, first group was control healthy persons, second group was given garlic capsules (500mg) twice daily, third group was given atorvastatin (40mg-Gulf pharmaceutical), fourth group was given both garlic capsules + atorvastatin. Results: After 12 week the garlic + atorvastatin treated group had good results in reduction of total cholesterol (5.23±0.12) triglycerides (1.93±0.12) LDL (1.31±0.14) VLDL (0.87±0.15) as compared with those before treatment. Conclusion: This study suggests that using garlic capsules + atorvastatin in treating dyslipidemia patients are efficiently reduced serum total cholesterol, LDL,VLDL and moderately raised HDL cholesterol as compared with non-treated group ,in addition prolong duration of treatment will assess the benefit effect of garlic + atorvastatin in treatment of dyslipidemia and other cardiovascular system diseases

Towards an Adaptive Design of Quality, Productivity and Economic Aspects When Machining AISI 4340 Steel With Wiper Inserts

The continuous pursue of sustainable manufacturing is motivating the utilization of new advanced technology, especially for hard to cut materials. In this study, an adaptive approach for optimization of machining process of AISI 4340 using wiper inserts is proposed. This approach is based on advance yet intuitive modeling and optimization techniques. The approach is based on Artificial Neural Network (ANN), Multi-Objective Genetic Algorithm (MOGA), as well as Linear Programming Techniques for Multidimensional Analysis of Preference (LINMAP), for modeling, optimization and multi-criteria decision making respectively. This integrated approach, to best of the authors’ knowledge, has been deployed for the first time to adaptively serve different designs of manufacturing processes. Such designs have different orientations, namely cost, quality, productivity, and balanced orientation. The capability of the proposed approach to serving such diverse requirements answers one of the most accelerating demands in the manufacturing community due to the dynamics of the uprising smart production lines. Besides, the proposed approach is presented in a straightforward manner that can be extended easily to other design orientations as well as other engineering applications. Based on the proposed design, a balanced general setting of 197.4 m/min, 0.95 mm, and 0.168 mm/rev was recommended along with other settings for more sophisticated requirements. Confirmatory experiments showed a good agreement (i.e., no more than 7% deviation) with the predicted optimum responses. This shows the validity of the proposed approach as a viable tool for designers to promote holistic and sustainable process design