220 research outputs found

    SYNTHESIS AND CHARACTERIZATION OF NEW COUMARIN DERIVATIVES CONTAINING VARIOUS MOIETIES WITH ANTIBACTERIAL ACTIVITIES

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    Objective: The purpose of this research is to evaluate the antibacterial activity of different moieties (Schiff bases, chalcones, hydrazones and hydrazinyl thiazole) derivatives, inserted at carbon 8 of 7-hydroxy-4-methyl coumarin, using in vitro, serial broth dilution method.Methods: A series of new coumarin derivatives, including (Schiff bases, chalcones, hydrazones and hydrazinyl thiazole), were prepared from 7-hydroxy-4-methyl coumarin, by insertion of the formyl group, at carbon number 8 using Duff reaction. The structure of the new synthesized derivatives elucidated and confirmed utilizing the corresponding analytical and spectroscopic data; including FT-IR, 13C-NMR, and mass spectroscopy. All new coumarin derivatives have been screened for their preliminary antibacterial activity, by serial broth dilution method against two Gram-positive bacteria (Staphylococcus epidermidis and Staphylococcus hemolyticus) and two Gram-negative bacteria (Escherichia coli and Klebsiella pneumoniae).Results: All the synthesized compounds have been found to exhibit considerable antibacterial activity in vitro. Among all the derivatives, compound (5a), showed the highest rate of inhibition, against (Escherichia coli), while compound (6a), showed the greatest anti-bacterial activity against (Staphylococcus hemolyticus), each with minimum inhibitory concentration of (25µg/ml), and the highest MIC of 200 µg/ml for compound 2, against. Klebsiella pneumoniae.Conclusion: Our results displayed a substantial preliminary antibacterial activity of the new coumarin moieties, especially some hydrazones and chalcones at C8 of the coumarin nucleus, against Gram-positive and a Gram-negative bacteria with distinguished MIC.Â

    AN IMPROVED NEWTON METHOD FOR RADIAL DISTRIBUTION SYSTEM LOAD ANALYSIS

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    This paper presents a modified Newton method of load flow analysis for radial distribution systems. It is derived with the Jacobian matrix is in UDUT form, where U is a constant upper triangular matrix depending solely on system topology and D is a block diagonal matrix. With this formulation, the conventional steps of forming the Jacobian matrix, LU factorization and forward/back substitution are replaced by back/forward sweeps on radial feeders with equivalent impedances. The method has advantages over Newton’ s method in terms of speed of solution (no. of iterations), and reliability of convergence by inserting a minimization technique (Cubic Interpolation Technique). The algorithm exhibits a control of the convergence. As such the method converges for cases when conventional Newton’ s method and some other popular methods diverge. Two large distribution systems of 490 nodes and 722 nodes with different r/x ratio in line impedance are used to examine the performance of the method. These tests have shown that the proposed method is as robust and efficient as the forward/back sweep method. The proposed method can be extended to the solution of three phase unbalanced representation

    Classification of first branchial cleft anomalies: is it clinically relevant?

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    Background: There are three classification systems for first branchial cleft anomalies currently in use. The Arnot, Work and Olsen classifications describe these lesions on the basis of morphology, tissue of origin and clinical appearance. However, the clinical relevance of these classifications is debated, as they may not be readily applicable in all cases and may provide no additional information on how the lesion should be managed.Objective: We seek to investigate this issue by applying these classification systems to cases from our centre and evaluating the information gained.Patients and methods: A retrospective case note review of all first branchial cleft anomalies excised at our institution between 2004 and 2014 was carried out, recording patient demographics, information on the anomalies and how they were investigated and managed.Results: This search identified eight unilateral cases and one bilateral case of first branchial cleft anomalies. These were a heterogenous group of lesions, which were variably investigated and managed. Categorization of these cases into Arnot, Work and Olsen subtypes did not correlate with the lesion’s relation with the facial nerve or the outcome of excision.Conclusion: The current classification systems used for first branchial cleft anomalies have little clinical relevance apart from providing extensive descriptions to aid in diagnosis. We advise instead that clinicians use imaging techniques to gain as much information as possible about these lesions before excision and be aware of the risk to the facial nerve at the time of excision. A description of the lesion’s relation with the facial nerve at the time of excision may provide more information on the likely outcomes compared with the classifications currently in use.Keywords: branchial cleft, congenital anomaly, facial nerve injury, first branchial cleft anomal

    MATHEMATICAL ANALYSIS OF 2-D STEADY SEEPAGE FLOW AND THE BEHAVIOR OF CONTAMINATES TRANSPORTATION THROUGH HOMOGENEOUS EARTH DAM USING COMSOL SOFTWARE

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    Seepage is a flow that happens through / under hydraulic structures or through the porous media such as in the case of earth dams from upstream to downstream due to difference in the hydraulic head. Study of seepage flow is important for hydraulic engineering. Before the structures being built, the behaviors of the seepage flows must be predicted because the seepage flow causes harmful to hydraulic structures. In this paper, a homogenous earth dam with sand material is proposed and constructed with horizontal bed filter at the Toe of the dam is taken as a case study. Through this Comsol is used to interpret the seepage of flow and contaminants transportation through the dam. The general objective of this paper is thus to present a prediction model aimed at quantifying a selected concentration of contaminants in the reservoir, and then predicted in the body of the dam, and at the exit from the dam. Computation Fluid Dynamics (CFD) Module (Comsol version 4.2) with its sub-programs named (Free and Porous Media Flow and Species Transport through Porous Media) was used in the analysis and study the seepage flow and of the contaminants transportation. This software is based on the finite element techniques that were used for solving the governing equations of flow and transportation of contaminant through porous media. Also, it was used to determine the phreatic line, amount of seepage within the dam, the pressure head, the total head, and the amount of contaminates transported through the dam body. From the comsol software, it is deduced that when the water level is at the maximum height (20m), it needs 12 days and (18) hr, at normal height (15m) it needs 29 days, while at a minimum height (8 m) it needs 81 days to reach the drain zone

    Comparative histopathology and immunohistochemistry of human and canine mammary tumors

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    This study aimed at establishing aspects of comparison between canine and human mammary gland tumors. In order to achieve that, 44 specimens of canine mammary tumors and 70 specimens of human breast tumors were examined in order to state points of similarity in morphology, cells of origin, behavior and existence of tissue markers. We found that the ratio of benign to malignant forms was 4.5% to 95.5% in canine samples and 45.7% to 54.3% in human samples. In both species, malignant tumors composed of infiltrating ductal cells were in the forefront despite dissimilarity in nomenclature. Other kinds of lower rate of existence included, invasive micro-papillary carcinoma, mucinous carcinoma and invasive comedo-carcinoma which have displayed similar morphology and terminology in both species. Chondroid and squamous differentiation were found in human and canine specimens. In human samples, fibro-adenoma mounted up to 30 out of 32 benign tumors (93.8%). Her-2 and Ki-67 were detected in the specimens of both species but ER was detected in human specimens only. Our findings suggest a significant degree of resemblance between certain mammary tumor in canine and human. Such findings are in support of employing dogs in research investigation for human mammary tumors

    Satisfaction and compliance in hormonal contraception: the result of a multicentre clinical study on women's experience with the ethinylestradiol/norelgestromin contraceptive patch in Italy

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    <p>Abstract</p> <p>Background</p> <p>For many women finding the right contraceptive method can be challenging and consistent and correct use over a lifetime is difficult. Even remembering to take a birth control pill every day can be a challenge. The primary objective of this study was to evaluate women's experience with a weekly ethinylestradiol/norelgestromin contraceptive patch (EE/NGMN patch), given new technologies recently developed in hormonal contraception to increase women's options in avoiding daily dosing.</p> <p>Methods</p> <p>In 24 Italian sites, 207 women received the EE/NGMN patch for up to 6 cycles. At study end, overall satisfaction and preference, as well as compliance, efficacy and safety, were evaluated.</p> <p>Results</p> <p>175 women (84.5%) completed the study. The overall satisfaction rate was 88%; convenience and once-a-week frequency of the patch were especially appreciated. At baseline, 82 women (39.4%) were using a contraceptive method, mainly oral contraceptives and barrier methods, but only 45.1% were very satisfied/satisfied; after 6 months with the patch, 86.3% of this subset was very satisfied/satisfied. Considering the method used in the 3 months before the study entry, 78.1% strongly preferred/preferred the patch, for convenience (53.9%), ease of use/simplicity (28.9%), fewer (9.2%) and less severe (2.6%) side effects. Compliance was very high: 1034/1110 cycles (93.2%) were completed with perfect compliance and the mean subject's compliance score was 90%. One on-therapy pregnancy occurred. The patch was safe and well tolerated: adverse events frequency was low, with predominantly single reports of each event. Most of them started and subsided during cycle 1.</p> <p>Conclusion</p> <p>This study demonstrated that the EE/NGMN patch is associated with high satisfaction levels and excellent compliance. At study end, the majority of women indicated that they would continue using the patch.</p

    Efficacy and Safety of an Injectable Combination Hormonal Contraceptive for Men

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    CONTEXT: The development of a safe and effective reversible method of male contraception is still an unmet need. OBJECTIVE: Evaluation of suppression of spermatogenesis and contraceptive protection by coadministered im injections of progestogen and testosterone. DESIGN: Prospective multicentre study. SETTING: Ten study centers. PARTICIPANTS: Healthy men, aged 18-45 years, and their 18- to 38-year-old female partners, both without known fertility problems. INTERVENTION: Intramuscular injections of 200-mg norethisterone enanthate combined with 1000-mg testosterone undecanoate, administered every 8 weeks. MAIN OUTCOMES MEASURES: Suppression of spermatogenesis by ejaculate analysis, contraceptive protection by pregnancy rate. RESULTS: Of the 320 participants, 95.9 of 100 continuing users (95% confidence interval [CI], 92.8-97.9) suppressed to a sperm concentration less than or equal to 1 million/mL within 24 weeks (Kaplan-Meier method). During the efficacy phase of up to 56 weeks, 4 pregnancies occurred among the partners of the 266 male participants, with the rate of 1.57 per 100 continuing users (95% CI, 0.59-4.14). The cumulative reversibility of suppression of spermatogenesis after 52 weeks of recovery was 94.8 per 100 continuing users (95% CI, 91.5-97.1). The most common adverse events were acne, injection site pain, increased libido, and mood disorders. Following the recommendation of an external safety review committee the recruitment and hormone injections were terminated early. CONCLUSIONS: The study regimen led to near-complete and reversible suppression of spermatogenesis. The contraceptive efficacy was relatively good compared with other reversible methods available for men. The frequencies of mild to moderate mood disorders were relatively high

    The role of atopy in otitis media with effusion among primary school children: audiological investigation

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    Objective of this study is to value the role of atopy in otitis media with effusion (OME) in children attending primary school in Western Sicily focusing on the audiological characteristics among atopic and non atopic subjects suffering from OME. 310 children (5-6 years old) were screened by skin tests and divided into atopics (G1) and non atopics (G2). The samples were evaluated for OME by pneumatic otoscopy, tympanogram and acoustic reflex tests. The parameters considered were: documented persistent middle ear effusion by otoscopic examination for a minimum of 3 months; presence of B or C tympanogram; absence of ipsilateral acoustic reflex and a conductive hearing loss greater than 25 dB at any one of the frequencies from 250 Hz through 4 kHz. 56 children (18.06%) resulted atopics while 254 were non atopics. OME was identified in 24 atopic children and in 16 non atopic children for a total number of 40 children; the overall prevalence rate was 12.9% (42.85% for G1 and 6.30% for G2). OME was bilateral in 28 children (70%), with a significative difference between G1 (79.17%) and G2 (56.25%). The prevalence of B tympanogram was 70.59%, corresponding to 79.07% for G1 and 56% for G2. The mean air conduction pure tone was respectively 31.97 dB for G1 and 29.8 dB for G2. The prevalence value of OME in atopics children, also supported by the higher predominance of bilaterality, B tympanogram and hearing loss among this group, could suggest the important role of allergy in the pathogenesis of OME

    Topical use of MMC in the upper aerodigestive tract: a review on the side effects

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    Not much is known about the side effects of mitomycin C (MMC), an anti-fibrogenetic agent, in the upper aerodigestive tract. However, its use in ophthalmology is widely known and without quantitatively important side effects. A literature review was performed for side effects of MMC in the upper aerodigestive tract. Forty-six articles, describing the use of MMC to prevent scarring, were retracted from PubMed. Thirty-two are human studies. MMC is used in different concentrations (0.1–10 mg/ml) with different application times (2–5 min) and frequencies (up to 4 times). Five hundred and thirty-eight patients were included in those publications, of whom 19 developed side effects (3.53%). No side effects developed in studies, where post-application irrigation with saline was reported. The longest mean follow-up period is 75.5 months. Direct relations between the reported side effects and MMC seem absent in most studies. Serious complications seem to occur when MMC is used in high concentrations. Unfortunately, sometimes crucial information is lacking. One patient was described who supposedly developed laryngeal carcinoma after repeated treatment of hyperkeratosis and anterior commissure webbing. Animal studies show that excessive fibrin production can lead to acute airway obstruction. In conclusion, topical application of MMC on a wound with consecutive irrigation with saline can be performed safely to prevent scar formation in circular structures of the upper aerodigestive tract. Long-term yearly control of the application site seems advisable
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