1,533 research outputs found

    The Genus Striga (Scrophulariaceae) in Africa

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    Twenty-eight species and six subspecies of the hemiparasitic genus Striga Lour., witchweed, occur in Africa. Twenty-two species are endemic. Witchweeds occur throughout the continent with greatest diversity in the grasslands and savannas north of the equator. Striga gesnerioides (Willd.) Vatke and S. hermonthica (Del.) Benth. have developed host-specific strains that may have distinct morphotypes. me accord these no formal taxonomic status. Striga hermonthica and S. asiatica (L.) Kuntze, limited to agroecosystems, may be recently derived from non-ruderal species. Striga hirsuta Benth. and S. lutea Lour., sometimes treated as conspecific with S. asiatica, are recognized as distinct species restricted to natural ecosystems. Striga linearifolia Hepper, with its strongly bilabiate corolla and perennial habit, is considered as a subspecies of S. bilabiata (Thunb.) Kuntze. Striga baumannii Engl. and S. fulgens Hepper are excluded from the genus. Striga baumannii has tuberous roots and a ligneous calyx and may represent a distinct genus. Striga fulgens, with free petals, is aligned with Chascanum E. Mey. in the Verbenaceae

    Study of microRNAs-21/221 as potential breast cancer biomarkers in Egyptian women

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    microRNAs (miRNAs) play an important role in cancer prognosis. They are small molecules, approximately 17–25 nucleotides in length, and their high stability in human serum supports their use as novel diagnostic biomarkers of cancer and other pathological conditions. In this study, we analyzed the expression patterns of miR-21 and miR-221 in the serum from a total of 100 Egyptian female subjects with breast cancer, fibroadenoma, and healthy control subjects. Using microarray-based expression profiling followed by real-time polymerase chain reaction validation, we compared the levels of the two circulating miRNAs in the serum of patients with breast cancer (n = 50), fibroadenoma (n = 25), and healthy controls (n = 25). The miRNA SNORD68 was chosen as the housekeeping endogenous control. We found that the serum levels of miR-21 and miR-221 were significantly overexpressed in breast cancer patients compared to normal controls and fibroadenoma patients. Receiver Operating Characteristic (ROC) curve analysis revealed that miR-21 has greater potential in discriminating between breast cancer patients and the control group, while miR-221 has greater potential in discriminating between breast cancer and fibroadenoma patients. Classification models using k-Nearest Neighbor (kNN), Naïve Bayes (NB), and Random Forests (RF) were developed using expression levels of both miR-21 and miR-221. Best classification performance was achieved by NB Classification models, reaching 91% of correct classification. Furthermore, relative miR-221 expression was associated with histological tumor grades. Therefore, it may be concluded that both miR-21 and miR-221 can be used to differentiate between breast cancer patients and healthy controls, but that the diagnostic accuracy of serum miR-21 is superior to miR-221 for breast cancer prediction. miR-221 has more diagnostic power in discriminating between breast cancer and fibroadenoma patients. The overexpression of miR-221 has been associated with the breast cancer grade. We also demonstrated that the combined expression of miR-21 and miR-221can be successfully applied as breast cancer biomarkers

    Bond Strength of Concrete Containing Different Recycled Coarse Aggregates

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    Some of the remnants of construction demolition wastes could be used after recycling as coarse aggregate in concrete industry. Among these wastes are ceramics, shale bricks and hardened concrete. This research was carried out to determine the effect of using such recycled aggregate (RA) as total or partial replacement of the natural dolomite coarse aggregate in concrete mixes on their compressive and bond strength with steel bars. Two types of concrete were investigated in this research which included normal concrete and self-compacted concrete. The main variables taken into consideration wee, the type of concrete, the type and percentage of the recycled aggregate and the age of testing. The consistency of the normal fresh concrete was measured by the slump test. However, the workability and flowability of the self-compacted fresh concrete were measured using slump test, V-funnel test. Out of the experimental test results, equations were predicted which correlated between the concrete compressive strength and bond strength of both the recycled aggregate ordinary concrete and the recycled aggregate self-compacted concrete. These equations were completely different than that of the steel-concrete bond equation of concrete with natural aggregate. Out of this research results, the recycled aggregate concrete could be used in both non structural applications and in some structural applications with special precautions

    Feasibility of using self-compacting concrete in civil engineering applications

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    This research aimed to investigate the feasibility of using self-compacting concrete in civil engineering applications as a producing a precast hollow unit. The behavior of the hollow sections cast with self-compacted concrete beneath line-load was evaluated. An experimental work was carried out and a finite element model with ANSYS (version 15) was adopted. A total of fourteen hollow beams were cast and tested. The most variables taken into thought were; the types of reinforcement (reinforced steel bar and steel wire meshes), the types of steel wire meshes (expanded and welded steel wire mesh), number of layers of steel meshes (one layer and two layers), cross section thickness of concrete (40 mm and 60mm), concrete cover thickness (15mm and 20 mm) and also the shapes of cross section (square or circular). Special attention to initial cracking load, ultimate load, deflection, cracking pattern, energy absorption and ductility index were investigated. Good agreement was found compared with the experimental results. Out of this research; this paper presents applications of self-compacted concrete for casting skinny structural hollow members. These members can be used as precast units within the construction of the tunnel to decrease the problems in highway roads due to the difficulty of using crossing bridges particularly for kids and old people which are very useful for developing countries with great economic advantages

    Assessment of Sperm Morphometry in Evaluating Male Infertility

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    Background: Infertility is a complex issue affecting 15% of couples of reproductive age, with men accounting for 40%-50% of infertility cases. Semen analysis comprises various descriptive measures of sperm and seminal fluid to determine semen quality. Transforming qualitative descriptions of sperm deformities and shape changes into quantitative terms can aid in identifying sub-visual abnormalities. This study aimed to evaluate sperm morphometry parameters in both infertile and fertile men. Methods and Results: The study enrolled a total of 101 participants, divided into three groups: Group A included 38 subfertile patients with varicocele, Group B included 33 patients with idiopathic infertility (23 with asthenozoospermia and 10 with oligozoospermia), and Group C (the control group) included 30 healthy fertile men. The mean age of patients was 31.6±5.81, 31.3±6.0, and 29.47±4.27 years in Groups A, B, and C, respectively. Scrotal duplex examinations were performed to identify the presence of varicocele. Semen samples were collected following WHO Manual (2010). Semen dynamic and morphological analyses were conducted using CASA (Computer-Assisted Semen Analysis, MIRALAB, ISO9001, ISO13485). We found that sperm concentration, total sperm count, sperm progressive motility, and sperm progressive+non-progressive motility were significantly lower in Group A and Group B than in Group C (P=0.000 in all cases); however, there were no differences between Group A and Group B regarding these parameters (Table 5). The sperm morphology index was significantly lower in Group A than in Group C (P=0.0024); no differences were found between Group B and Group C and Group B and Group A. The mean value of the sperm deformity index was significantly lower in Group A than in Group C P=0.004). Conclusion: Our study highlights the significant association between sperm morphology and male infertility in varicocele and idiopathic subfertile males

    Optimization of PID Parameters Utilizing Variable Weight Grey-Taguchi Method and Particle Swarm Optimization

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    Controller that uses PID parameters requires a good tuning method in order to improve the control system performance. Tuning PID control method is divided into two namely the classical methods and the methods of artificial intelligence. Particle swarm optimization algorithm (PSO) is one of the artificial intelligence methods. Previously, researchers had integrated PSO algorithms in the PID parameter tuning process. This research aims to improve the PSO-PID tuning algorithms by integrating the tuning process with the Variable Weight Grey-Taguchi Design of Experiment (DOE) method. This is done by conducting the DOE on the two PSO optimizing parameters: the particle velocity limit and the weight distribution factor. Computer simulations and physical experiments were conducted by using the proposed PSO-PID with the Variable Weight Grey-Taguchi DOE and the classical Ziegler-Nichols methods. They are implemented on the hydraulic positioning system. Simulation results show that the proposed PSO-PID with the Variable Weight Grey-Taguchi DOE has reduced the rise time by 48.13% and settling time by 48.57% compared to the Ziegler-Nichols method. Furthermore, the physical experiment results also show that the proposed PSO-PID with the Variable Weight Grey-Taguchi DOE tuning method responds better than Ziegler-Nichols tuning. In conclusion, this research has improved the PSO-PID parameter by applying the PSO-PID algorithm together with the Variable Weight Grey-Taguchi DOE method as a tuning method in the hydraulic positioning system

    Laser processing of La61.4Al15.9Ni11.35Cu11.35 based functionally graded material bulk metallic glass

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    Bulk metallic glass (BMG) based on lanthanum is one of the BMG with exceptional glass-forming ability (GFA). The La61.4Al15.9Ni11.35Cu11.35 bulk metallic glasses were treated to a laser processing test in this experiment. The results showed that the best power, frequency, and speed ranges for laser processing of the La61.4Al15.9Ni11.35Cu11.35 BMG samples are 40 – 50 W, 160 – 240 kHz, and 200 – 400 mm/s, respectively. As a result, the current work was effective in producing the Lanthanum-based functionally graded material (FGM) BMG. The positive findings on the laser's microstructural or morphology, give a solid foundation for future advancement research on the La61.4Al15.9Ni11.35Cu11.35 BMG

    Development of new thiazolidine-2,4-dione hybrids as aldose reductase inhibitors endowed with antihyperglycaemic activity: design, synthesis, biological investigations, and in silico insights

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    This research study describes the development of new small molecules based on 2,4-thiazolidinedione (2,4-TZD) and their aldose reductase (AR) inhibitory activities. The synthesis of 17 new derivatives of 2,4-TZDs hybrids was feasible by incorporating two known bioactive scaffolds, benzothiazole heterocycle, and nitro phenacyl moiety. The most active hybrid (8b) was found to inhibit AR in a non-competitive manner (0.16 µM), as confirmed by kinetic studies and molecular docking simulations. Furthermore, the in vivo experiments demonstrated that compound 8b had a significant hypoglycaemic effect in mice with hyperglycaemia induced by streptozotocin. Fifty milligrams per kilogram dose of 8b produced a marked decrease in blood glucose concentration, and a lower dose of 5 mg/kg demonstrated a noticeable antihyperglycaemic effect. These outcomes suggested that compound 8b may be used as a promising therapeutic agent for the treatment of diabetic complications
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