972 research outputs found

    Dynamic MR-Mammography as the best method for diagnosis of invasive lobular breast carcinoma: A retrospective study

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    AbstractAim of the studyIt is a retrospective study aiming to provide diagnostic characterization of ILC in Dynamic MR-Mammography and to compare its diagnostic performance to mammography and ultrasonography.Material and MethodA total of 56 cases of ILC were selected in retrospective review of mammography, ultrasonography and Dynamic MRM of 420 patients with invasive breast cancer.ResultsAsymmetric density was the commonest mammography finding and the measured sensitivity of mammography in detecting ILC was 87.5% (9/56 FN).The most common US manifestation of ILC was focal shadowing without a discrete mass and its sensitivity in detecting ILC was 84.9% (10/56 FN). At MR imaging, the most common manifestation of ILC was a solitary irregular or angular mass with speculated or ill-defined margins (33.9%of cases [n=19]).The measured sensitivity is 96.5% (2/56 FN). Additional data such as those affected the patient management including the presence of multifocal or multicentric disease, chest wall involvement and contralateral breast cancer were encountered in 48.2% of cases [n=27]. ILC has a tendency to demonstrate delayed maximum enhancement with washout exhibited by only a minority of lesions (21.4% [n=12]).ConclusionMR imaging has proved to be superior to mammography and US in the detection and management of ILC. It provides useful information for further management and pre-surgical planning

    Surveillance of nosocomial infections at a Saudi Arabian military hospital for a one-year period

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    The objectives of the current study are to define how many and what kind of nosocomial infections are occurring, what are the causative microbes and what kind of drugs can be used in treatment of infection at Al-Hada Armed Forces Hospital, Taif, Saudi Arabia during the year 2004. A prospective study was implemented for all cases admitted at Al-Hada Armed Forces Hospital during the period 1st January, 2004 till 31st December, 2004 and which developed infection. Determination of nosocomial infections was performed using standardized CDC criteria. A total of 1382 patients had developed infection during hospital admission and were included in the study. Of them, 668 (48.3%) had nosocomial infection and 714 (51.7%) had community-acquired infection. Among those who developed nosocomial infections, 216 (32.3%), 172 (25.7%) and 124 (18.6%) had respiratory tract (RTI), urinary tract (UTI) and blood stream infections (BSI) respectively. Surgical site infection (SSI) was reported in 86 cases (12.9%). The overall nosocomial infection rate along the study period was 4.98 per 100 discharged patients. Gram-positive organisms were reported in 31.8%. MRSA (Methicillin-resistant S. aureus) was the commonest (10.2%), followed by coagulase negative staphylococci (8.5%) and MSSA (Methicillin-susceptible S. aureus, 7.4%). While Gram-negative organisms were reported in 66.2%, E. coli was the commonest (22.3%), followed by Pseudomonas aeruginosa (17.6%) and Klebsiella pneumoniae (9.9%). Acinetobacter spp. and MRSA were highly sensitive to Imipenem (88.6%) and Vancomycin (98.5%) respectively. E. coli were highly sensitive to most of the antimicrobial agents except ampicillin (26.6%)

    Color and Weave Relationship in Woven Fabrics

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    Comparison of Electrochemical Polishing Treatments between Phosphoric Acid and a Deep Eutectic Solvent for High-Purity Copper

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    This study investigated and compared the acid-free electropolishing of copper with the state-of-the-art acidic electropolishing process. The acid-free medium used in this study is based on a deep eutectic solvent comprised of 2:1 ethylene glycol and choline chloride. The electrochemical study included voltammetry and chronoamperometry tests during the electropolishing process. The characterization techniques used were atomic force microscopy (AFM) and digital microscopy, and surface morphology comparisons summarized the electropolishing efficiency of phosphoric acid and acid-free deep eutectic solvent treatments for high-purity copper. Electropolishing copper with a deep eutectic solvent resulted in a mirror finish and a post-treatment surface that was 8× smoother than the original metal surface prior to electropolishing treatments with a smoothing efficiency of 91.1 ± 1.5%. This eco-friendly solution produced polished surfaces superior to those surfaces treated with industry standard acid electrochemistry treatments of 1 M H3PO4

    Comparison of Electropolishing of Aluminum in a Deep Eutectic Medium and Acidic Electrolyte

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    Research advances in electropolishing, with respect to the field of metalworking, have afforded significant improvements in the surface roughness and conductivity properties of aluminum polished surfaces in ways that machine polishing and simple chemical polishing cannot. The effects of a deep eutectic medium as an acid-free electrolyte were tested to determine the potential energy thresholds during electropolishing treatments based upon temperature, experiment duration, current, and voltage. Using voltammetry and chronoamperometry tests during electropolishing to supplement representative recordings via atomic force microscopy (AFM), surface morphology comparisons were performed regarding the electropolishing efficiency of phosphoric acid and acid-free ionic liquid treatments for aluminum. This eco-friendly solution produced polished surfaces superior to those surfaces treated with industry standard acid electrochemistry treatments of 1 M phosphoric acid. The roughness average of the as-received sample became 6.11 times smoother, improving from 159 nm to 26 nm when electropolished with the deep eutectic solvent. This result was accompanied by a mass loss of 0.039 g and a 7.2 µm change in step height along the edge of the electropolishing interface, whereas the acid treatment resulted in a slight improvement in surface roughness, becoming 1.63 times smoother with an average post-electropolishing roughness of 97.7 nm, yielding a mass loss of 0.0458 g and a step height of 8.1 µm

    Synthesis and efficiency of new pyridine, chromene and thiazole containing compounds as antimicrobial and antioxidant agents

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    ABSTRACT. The versatile scaffold, N'-(2-cyanoacetyl)-2-hydroxybenzohydrazide (3) was utilized in the production of new pyridine, chromene and thiazole derivatives as antimicrobial and antioxidant agents. The synthetic strategy involves the treatment of precursor 3 with various arylidene-malononitrile and 3-aryl-2-cyanoacrylate compounds to furnish substituted pyridines 5 and 7. The interaction of 3 with salicylaldehyde and/or phenyl isothiocyanate followed by cyclization with chloroacetone produced the corresponding 2-imino-2H-chromene-3-carbohydrazide and (thiazol-2-ylidene-acetyl)-salicylic acid hydrazide compounds 8 and 9, respectively. The structural features of the synthesized compounds were confirmed by using spectroscopic methods such as (IR, 1H NMR, 13C NMR and MS). The new pyridine, chromene and thiazole products showed potent antioxidants and antimicrobial activities. The thiazole derivative 9 exhibited the highest anti-bacterial and antifungal activities against S. aureus (75.0%) and B. subtilis (73.9%) and C. albicans (66.6%). The combination between salicylic acid hydrazide and thiazole moieties in the hybrid 9 indicated the best antioxidant activity (87.9%).                 KEY WORDS: Salicylic hydrazide, Arylidene-malononitrile, Pyridine, Thiazole, Antioxidant   Bull. Chem. Soc. Ethiop. 2022, 36(1), 137-148.                                                            DOI: https://dx.doi.org/10.4314/bcse.v36i1.12                                                      &nbsp

    A Simulation Model for Hierarchical Routing Protocols in Wireless Sensor Networks

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    One of the critical issues in wireless sensor network is power saving scheme as network should be considered to operate more efficiently. The sensor nodes are usually operated by a finite number of batteries and it should have a certain lifetime for gathering, processing, and transmitting information. Since some sensor nodes may fail due to lack of power, this consideration has led to give more interest about routing protocols. Depending on the network structure, a sensor network can be hierarchical or cluster-based hierarchical model, where the nodes will play different roles in the networks. We present three different types of routing protocols: LEACH, PEGASIS, and VGA, several simulations are conducted to analyze the performance of these protocols including the power consumption and overall network performance. On the average, VGA has the worst power consumption when the sensing range is limited, while VGA is the best when the sensing range is increased

    Review of Alternative Modernities in French Travel Writing: Engaging Urban Space in London and New York, 1851–1986 by Gillian Jein.

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    Review of Alternative Modernities in French Travel Writing: Engaging Urban Space in London and New York, 1851–1986 by Gillian Jein

    Nonuniformity in Lattice Contraction of Bismuth Nanoclusters Heated Near Its Melting Point

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    The structural properties of bismuth nanoclusters were investigated with transmission high-energy electron diffraction from room temperature up to 525 ± 6 K. The Bi nanoclusters were fabricated by thermal evaporation at room temperature on transmission electron microscope grids coated with an ultrathin carbon film, followed by thermal and femtosecond laser annealing. The annealed sample had an average cluster size of ∼14 nm along the minor axis and ∼16 nm along the major axis. The Debye temperature of the annealed nanoclusters was found to be 53 ± 6 K along the [012] direction and 86 ± 9 K along the [110] direction. At T = 464 ± 6 K, the diffraction intensity started to deviate from Debye-Waller behavior due to increased lattice anharmonicity. The onset of the melting of the Bi nanoclusters was T ∼ 500 ± 6 K, as measured by the reduction of the nanocluster size through the formation of a liquid shell detected by the width of the diffraction rings. The thermal expansion coefficient of the Bi (012) and (110) planes is positive up to ∼ 499 11 K. However, the expansion coefficient of the Bi (012) planes showed a transition from a positive to a negative value that occurs over the temperature range Tc ∼ 499 ± 11 K to 511 ± 8 K. For the Bi (110) planes, the thermal expansion coefficient is positive up to their melting point, which is 525 ± 6 K. © 2011 American Institute of Physics. [doi:10.1063/1.3565028

    Efficient Removal of Lead Ions from Aqueous Media Using Sustainable Sources on Marine Algae

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    The goal of this project is to explore a new method to efficiently remove Pb(II) ions from water by processing Undaria pinnatifida into immobilized beads using sodium alginate and calcium chloride. The resulting biosorbent was characterized by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy (SEM-EDS). Using immobilized U. pinnatifida, we investigated the effect of various factors on Pb(II) ion removal efficiency such as temperature, pH, ionic strength, time, and underlying biosorption mechanisms. For Pb(II) ion biosorption studies, Pb(II) ion biosorption data were obtained and analyzed using Langmuir and Freundlich adsorption models. It is found that the maximum Pb(II) ion adsorption capacity (Xm) of U. pinnatifida was estimated to be ∼5 times greater than that of activated carbon, indicating the superior Pb(II) ion removal capability of U. pinnatifida compared to activated carbon. In addition, a thermodynamic study indicates that biosorption processes are found to be endothermic and an increase in the Pb(II) ion solution temperature provides a more preferential reaction toward Pb(II) ion biosorption
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