815 research outputs found

    Mitigation of voltage sag and voltage swell by using dynamic voltage restorer

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    Recent power quality (PQ) research shows that the most common types of power quality disturbances are voltage sags and swells in medium and low-voltage distribution grids. This paper shows how to improve two significant power quality disturbances: sags and swells voltage. To find out what effect these two PQ issues have in real life, a study case based on real nonlinear loads data from large induction motors at Beshai Company in Sadat City in Egypt is investigated. The dynamic voltage restorer (DVR) has been suggested as a solution to the voltage swell and voltage sag issues. The point of common coupling (PCC) is linked with the dynamic voltage restorer to mitigate the PQ problems that have been found. The power network, loads, and DVR may all be modeled using the MATLAB/Simulink platform. The jellyfish search optimizer (JFS) is used to get the gain settings of the proportional and integral (PI) controller for the proposed DVR. MATLAB/Simulink's results show that the proposed device is effective, reliable, and has low latency

    CXCR3 renal expression in glomerulonephritis in children: is there a connection with the course of the disease?

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    Background: Glomerulonephritis (GN) is a common childhood disease that may represent a significant cause of chronic kidney disease at one point of its course. The role of chemokines in glomerulonephritis, has been long anticipated and studied and the possible link between certain chemokines and different renal pathologies, if proved, can pave the road for future use of such markers for early prognosis and possible therapies for this common disease.Objective: in this study, we aimed at detecting CXCR3 in the renal biopsies done for children with glomerulonephritis and to correlate it to the nature of renal pathology and response to therapy.Methods: The glomerular and interstitial expression of CXCR3 in renal biopsies done for 22 patients with glomerulonephritis was studied using immunohistochemical staining. Pathologies already diagnosed in these biopsies were proliferative GN (mesangioproliferative GN, diffuse proliferative GN, focal proliferative GN, IgA nephropathy and crescentic GN) as well as non-proliferative GN (Minimal change disease, focal segmental glomerulosclerosis, membranous nephropathy, diffuse mesangial sclerosis and advanced hypertensive nephrosclerosis). History, clinical findings and laboratory investigations in the initial presentation and at the time of the study were obtained.Results: The degree of glomerular and interstitial CXCR3 expression did not vary with gender, age of presentation, response to steroids, or cumulative doses of steroids. Percentage of strong glomerular CXCR3 expression was much higher in proliferative GN compared to non-proliferative GN although the difference was not statistically significant, percentage of renal dysfunction was more among strong glomerular and mild/moderate interstitial CXCR3 expression with no statistically significant difference from the counterparts.Conclusion: Our study revealed that enhanced CXCR3 renal expression on glomerular and interstitial levels did not affect the response to steroids along the course of the disease and so can probably act as a therapeutic target rather than a prognostic marker.Keywords: glom. CXCR3, int. CXCR3, glomerulonephritis, renal biops

    The diagnostic and monitoring value of serum anti-mutated citrullinated vimentin antibodies (anti-MCV) in juvenile rheumatoid arthritis

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    Background: JRA is currently diagnosed using the American College of Rheumatology (ACR) 1987 revised criteria that are primarily based on clinical parameters. The criteria may be insufficient for the diagnosis of early RA as they are based upon measurements of disease classification predominately featuring manifestations typical of later-stage disease. Measurement of serum anti-mutated citrullinated vimentin antibodies (MCV) has been shown to be a better marker for early adult RA, and it correlates well with the disease activity score (DAS). Objectives: The aim of this work is to evaluate the role of antimutated citrullinated vimentin antibodies (anti-MCV) in the diagnosis, and in monitoring disease activity in juvenile rheumatoid arthritis. Methods: The study included 40 children with JRA fulfilling the American College of Rheumatology criteria for diagnosis of JRA: 4 children with oligoarticular JRA, 12 with polyarticular JRA and 24 children with systemic onset JRA. Fifty healthy children, matching the patients in age and sex served as a control group. The studied children with JRA were subjected to laboratory tests including CBC, ESR, CRP, ANA and rheumatoid factor (RF). Serum samples from both patients and controls were assayed for anti-MCV levels using an ELISA technique. Results: The study showed high mean serum anti-MCV antibodies level in JRA patients when compared to controls (P= 0.00). In addition, there were no significant correlations between anti-MCV antibody levels and parameters of disease activity, namely, number of swollen joints, number of tender joints, ESR and CRP. The receiver operating characteristic (ROC) curve was drawn and it showed that the area under the curve (AUC) was (0.896). At a cutoff level > 17 u/mL, anti-MCV antibodies had diagnostic specificity of 88%, diagnostic sensitivity of 87.5%, negative and positive predictive values of 89.8% and 85.4%, respectively and diagnostic efficacy of 87.8%. We also reported 3/40 of JRA patients to be positive for RF and 2/40 of JRA patients to be positive for ANA. Conclusion: Measurement of serum anti MCV antibody level holds promise as a diagnostic tool in JRA. However, they failed to show a significant efficacy in determining disease activity.Keywords: Juvenile rheumatoid arthritis, MCVEgypt J Pediatr Allergy Immunol 2012;10(2):75-8

    Amenability of heap leaching technology on uranium extraction from Gattar and El Missikat area, Eastern Desert, Egypt: A kinetic approach

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    Studies of uranium heap leaching from different uranium mineralization situated in Eastern Desert of Egypt was investigated via batch experiments, followed by its optimum condition applicationon column percolationtests.The optimum process operating parameters were implemented on large column scale in order to make more condition control and evaluate the time and reagents needed in the large scale. The results show thatleaching efficiency of GIIattained about 78.3% with 34kg/ton acid consumption in a 44 days period, while leaching efficiency of El-Missikat attained about 86.6% with 28kg/ton acid consumption in a 40 days period.Kinetics reaction models of column tests have been investigated to optimize the column leaching behavior. Based on the leaching results of two mineralized samples, the rate of the uranium metal dissolution is controlled by the chemical reaction and the diffusion reaction but diffusion reaction control was more predominate than a chemical reaction control

    Quinazolinone-based rhodanine-3-acetic acids as potent aldose reductase inhibitors: Synthesis, functional evaluation and molecular modeling study

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    A series of quinazolinone-based rhodanine-3-acetic acids was synthesized and tested for in vitro aldose reductase inhibitory activity. All the target compounds displayed nanomolar activity against the target enzyme. Compounds 3a, 3b, and 3e exhibited almost 3-fold higher activity as compared to the only marketed reference drug epalrestat. Structure-activity relationship studies indicated that bulky substituents at the 3-phenyl ring of the quinazolinone moiety are generally not tolerated in the active site of the enzyme. Insertion of a methoxy group on the central benzylidene ring was found to have a variable effect on ALR-2 activity depending on the nature of peripheral quinazolinone ring substituents. Removal of the acetic acid moiety led to inactive or weakly active target compounds. Docking and molecular dynamic simulations of the most active rhodanine-3-acetic acid derivatives were also carried out, to provide the basis for further structure-guided design of novel inhibitors

    Design, synthesis and cytotoxic evaluation of 2-amino-4- aryl-6-substituted pyridine-3,5-dicarbonitrile derivatives

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    Purpose: To synthesize novel pyridine derivatives and evaluate their efficiency as potent inhibitors of cyclin dependent kinase 2 (CDK2) enzyme for cancer therapy.Methods: Pyridine scaffold were synthesized using one-pot multicomponent condensation reaction of arylidine with different primary amines. The cytotoxic potential of the new compounds was assessed using various cell lines. Furthermore, molecular docking studies based on the crystal structure of CDK2 was carried out to determine the possible binding modes that influence the anticancer activities.Results: The results indicate that one-pot multicomponent reaction generated a series of functionalized pyridines with good yield. In vitro cytotoxicity study revealed superior cytotoxicity of the designed compounds against prostate and cervical cancer cell lines compared to 5-fluorouracil (standard anticancer compound) with half-maximal inhibitory concentration (IC50) values of 0.1 – 0.85 and 1.2 –74.1 μM, respectively. Finally, molecular modeling simulation of the newly synthesized compounds showed that they fit well and are stabilized into CDK2 active site via hydrogen bonding and hydrophobic interactions.Conclusion: The results indicate that the newly synthesized pyridine can exert potent anticancer activity presumably via inhibition of CDK2. However, this will need to be confirmed in in vivo studies

    TOXICOLOGICAL AND PHARMACOLOGICAL ASSESSMENT OF GOLD NANORODS IN NORMAL RATS

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    Objective: assessment of acute, subchronic and chronic toxicity of pegylated gold nanorods (PEG-gold NRs) in Wistar rats of both sex in three routes of administration {intravenous (IV), intramuscular (IM) and subcutaneous (SC)}.Methods: in the acute toxicity study; PEG-gold NRs were injected once by three different routes, blood and tissue samples were collected after 14 d. In the subchronic and chronic studies; PEG-gold NRs were injected via three different routes, at 0.225, 0.45 and 0.9 mg/kg, once daily for 5 consecutive days, followed by a 23-day recovery period, for three and six months in the subchronic and chronic toxicity studies, respectively. Hematology, urinalysis, biochemical and histopathological examinations were conducted at the end of each study.Results: acute toxicity showed a significant decrease in serum triglycerides and cholesterol levels after single IV, IM and SC injection of PEG-gold NRs, while serum creatinine was significantly increased after IV and IM injection. Subchronic results revealed a significant decrease in serum triglycerides and cholesterol levels. The chronic study showed a significant decrease in serum triglycerides, sodium levels, total leukocytes count and significant increase in serum creatinine after IV injection. IM injection resulted in significant decrease in serum alkaline phosphatase, triglycerides, cholesterol, sodium levels and total leukocytes count. SC injection resulted in significant decrease in serum triglycerides, glucose, red blood cell count with increased creatinine and hematocrit.Conclusion: PEG-gold NRs at the three examined doses is apparently safe since no serious signs of toxicity were detected. IM and SC routes of injection were irritating, so we recommend the IV route.Â

    Metabolomic profile, anti-trypanosomal potential and molecular docking studies of <i>Thunbergia grandifolia</i>

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    Trypanosomiasis is a protozoan disease transmitted via Trypanosoma brucei. This study aimed to examine the metabolic profile and anti-trypanosomal effect of methanol extract of Thunbergia grandifolia leaves. The liquid chromatography-high resolution electrospray ionisation mass spectrometry (LC-HRESIMS) revealed the identification of fifteen compounds of iridoid, flavonoid, lignan, phenolic acid, and alkaloid classes. The extract displayed a promising inhibitory activity against T. brucei TC 221 with MIC value of 1.90 μg/mL within 72 h. A subsequent in silico analysis of the dereplicated compounds (i.e. inverse docking, molecular dynamic simulation, and absolute binding free energy) suggested both rhodesain and farnesyl diphosphate synthase as probable targets for two compounds among those dereplicated ones in the plant extract (i.e. diphyllin and avacennone B). The absorption, distribution, metabolism, excretion, and toxicity (ADMET) profiling of diphyllin and avacennone were calculated accordingly, where both compounds showed acceptable drug-like properties. This study highlighted the antiparasitic potential of T. grandifolia leaves

    Microstructural architecture of the bony scutes, spine, and rays of the bony fins in the common pleco (Hypostomus plecostomus)

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    Studying scute and fin morphology are advantageous approaches for phylogenetic identification and provide information on biological linkages and evolutionary history that are essential for deciphering the fossil record. Despite this, no prior research has precisely characterized the histological structures of scutes in the common pleco. Therefore, this research investigated the microstructure and organization of bone tissue within the dermal skeleton, including the scutes and fins, in the common pleco, using light microscopy, stereomicroscopy, and scanning electron microscopy. The dermal scutes were organized in a pentagonal shape with denticular coverage and were obliquely aligned with the caudal portion pointing dorsally. The dermal scutes consisted of three distinct portions: the central, preterminal, and terminal portions. Each portion comprised three layers: a superficial bony plate, a basal bony plate, and a mid-plate. Both the superficial and basal bony plates were composed of lamellar bone and lamellar zonal bone, whilst the mid-plate consisted of secondary osteons and woven bone. In the terminal portion, the superficial and basal bony plates became thinner. The pectoral fin consists of spines and rays composed of lepidotrichium (two symmetrical hemi-rays). The spine contained centrifugal and centripetal lamellar and trabecular bones. A centripetal fibrous bone was implanted between the lamellar bones. Besides being oriented in a V shape, the hemi-rays were also composed of thin centrifugal and centripetal lamellar bones and trabecular bones. A fibrous bone was identified between the centrifugal and centripetal bones. The trabecular bone and lamellar bone were made up of bone spicules
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