1,382 research outputs found

    Lesions mimicking lacrimal gland pleomorphic adenoma

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    Aim: To report a series of patients with lacrimal gland lesions simulating the clinicoradiological features of lacrimal gland pleomorphic adenoma (LGPA). Methods: Multicentre retrospective, interventional case series. Clinical records of all patients with lesions mimicking LGPA seen in five orbital units were reviewed. Results: The study included 14 patients (seven men and seven women) with a mean age of 50.9 years. The diagnosis of LGPA was made in all cases by experienced orbital surgeons, based on clinicoradiological features, and lacrimal gland excision was performed. Postoperative histology revealed lymphoma (four patients), chronic dacryoadenitis (three patients), adenoid cystic carcinoma (two patients), Sjogren's syndrome (two patients), cavernous haemangioma (one patient), benign lymphoid hyperplasia (one patient) and granulomatous dacryoadenitis (one patient). Comparison with the total number of histologically confirmed LGPA cases seen during the study period revealed that 22.6% of cases of suspected LGPA were misdiagnosed based on clinicoradiological criteria. Conclusions: Many different lesions may mimic the clinicoradiological features of LGPA. The accepted clinicoradiological criteria used for the diagnosis of LGPA have a high false-positive rate, even in experienced hands. Based on this study, the authors believe that fine-needle aspiration biopsy or intraoperative biopsy and frozen section diagnosis may help reduce unnecessary lacrimal gland excision.Venkatesh C Prabhakaran, Paul S Cannon, Alan McNab, Garry Davis, Brett Oā€™Donnell, Peter J Dolman, Raf Ghabrial, Dinesh Selv

    Critical Analysis on the Structural and Magnetic Properties of Bulk and Nanocrystalline Cu-Fe-O

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    Nanocrystalline and bulk samples of ā€œFeā€-doped CuO were prepared by coprecipitation and ceramic methods. Structural and compositional analyses were performed using X-ray diffraction, SEM, and EDAX. Traces of secondary phases such as CuFe2O4, Fe3O4, and Ī±-Fe2O3 having peaks very close to that of the host CuO were identified from the Rietveld profile analysis and the SAED pattern of bulk and nanocrystalline Cu0.98Fe0.02O samples. Vibrating Sample Magnetometer (VSM) measurements show hysteresis at 300ā€‰K for all the samples. The ferrimagnetic Neel transition temperature () was found to be around 465Ā°C irrespective of the content of ā€œFeā€, which is close to the value of cubic CuFe2O4. High-pressure X-Ray diffraction studies were performed on 2% ā€œFeā€-doped bulk CuO using synchrotron radiation. From the absence of any strong new peaks at high pressure, it is evident that the secondary phases if present could be less than the level of detection. Cu2O, which is diamagnetic by nature, was also doped with 1% of ā€œFeā€ and was found to show paramagnetic behavior in contrast to the ā€œFeā€ doped CuO. Hence the possibility of intrinsic magnetization of ā€œFeā€-doped CuO apart from the secondary phases is discussed based on the magnetization and charge state of ā€œFeā€ and the host into which it is substituted

    Studies on Phytochemical constituents, Functional Group Identification and Antimicrobial Activity of Solanum nigrum (Solanaceae)

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    Phytochemical constituents, functional group identification and antimicrobial activity of ethanolic extract of Solanum nigrum were investigated. The phytochemical screening of the crude extract revealed the presence of alkaloids, reducing sugars, tannis, flavonoids, Phlobatannis, and steriods. The extract were subjected for identification of functional groups using infra red spectrophotometer, presence of C=O, C-H, C=C and CO were identified, these bonding structures are responsible for presence of alkyl groups, methyl groups, alcohols, ethers, esters, carboxylic acid and anhydrides. And the crude ethanolic extract of Solanum nigrum were assayed for in vitro antimicrobial activity against gram positive and gram negative bacteria and they were also subjected for antifungal activity and the zone of inhibition were compared with control drug Penicillin and Nystatin. Staphylococcus aureus as the most sensitive strains exhibited maximum zone of inhibition about 25.7mm among gram positive organism tested. Escherichia coli exhibits 30.1mm zone than that of standard penicillin positive control. Trichophyton mentagrophytes exhibits maximum zone of inhibition of about 26.1mm among the tested fungal species

    Primary radiotherapy in progressive optic nerve sheath meningiomas: a long-term follow-up study

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    Background/aims: To report the outcome of primary radiotherapy in patients with progressive optic nerve sheath meningioma (ONSM). Methods: The clinical records of all patients were reviewed in a retrospective, observational, multicentre study. Results: Thirty-four consecutive patients were included. Twenty-six women and eight men received conventional or stereotactic fractionated radiotherapy, and were followed for a median 58 (range 51ā€“156) months. Fourteen eyes (41%) showed improved visual acuity of at least two lines on the Snellen chart. In 17 (50%) eyes, the vision stabilised, while deterioration was noted in three eyes (9%). The visual outcome was not associated with age at the time of radiotherapy (p=0.83), sex (p=0.43), visual acuity at the time of presentation (p=0.22) or type of radiotherapy (p=0.35). Optic disc swelling was associated with improved visual acuity (p<0.01) and 4/11 patients with optic atrophy also showed improvement. Long-term complications were dry eyes in five patients, cataracts in three, and mild radiation retinopathy in four. Conclusion: Primary radiotherapy for patients with ONSM is associated with long-term improvement of visual acuity and few adverse effects.Peerooz Saeed, Leo Blank, Dinesh Selva, John G. Wolbers, Peter J.C.M. Nowak, Ronald B. Geskus, Ezekiel Weis, Maarten P. Mourits, Jack Rootma

    Efficacy of endoscopic sinus surgery for paranasal sinus mucocele including modified endoscopic Lothrop procedure for frontal sinus mucocele

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    This study evaluated the efficacy of the modified endoscopic Lothrop procedure (MELP) for complicated frontal mucoceles and endoscopic marsupialization for other paranasal sinus mucoceles. It was a retrospective, consecutive case review of sinus mucoceles treated endoscopically by a single surgeon over a four-year period (1998-2002). There were 41 mucoceles in 28 patients, including 24 frontal, eight frontoethmoidal, three ethmoidal, five maxillary and one frontal mucocele. Twenty-one patients underwent the modified Lothrop procedure for frontal mucoceles, and seven underwent simple drainage and marsupialization for frontoethmoidal, ethmoidal and maxillary mucoceles. At median follow-up of 16 months, all patients had a patent mucocele opening. Patients treated by drainage and marsupialization did not have any complications or mucocele recurrence. All patients treated by the modified endoscopic Lothrop procedure had improvement in symptoms and signs. Four patients had minor complications including epistaxis and adhesions and five required further surgery. The average hospital in-patient stay was 2 Ā± 1.4 days. Endoscopic techniques, including MELP are effective in the short term for the management of complex and simple paranasal sinus mucoceles. MELP has a useful place in the management of mucoceles with a significant bony partition from an adjacent sinus or nasal cavity. It is also indicated when the mucocele is associated with loss of lateral support in the sinus with risk of medial-wall collapse of the orbital contents obstructing drainage.Jwu Jin Khong, Raman Malhotra, Dinesh Selva and Peter John Wormal

    Exploring the Trade-offs of Aggregated versus Disaggregated Architectures for Environmental Monitoring in Low-Earth Orbit

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    Traditionally, government space agencies have developed aggregated systems that co-host multiple capabilities on shared spacecraft buses. However, in response to cost growth and schedule delays on past programs, leaders in the government space community have expressed an interest in disaggregation, or distributing their capabilities across multiple spacecraft. Since their aggregated National Polar-orbiting Operational Satellite System (NPOESS) program was cancelled in 2010, both the National Oceanic and Atmospheric Administration (NOAA) and the Department of Defense (DoD) have investigated opportunities to reduce program costs through disaggregation. This paper expands their initial investigation and explores the cost impacts of aggregation and disaggregation across a large trade space of candidate architectures for environmental monitoring in low-Earth orbit. We find that on average, aggregated architectures are less costly than fully disaggregated ones but also find opportunities for cost savings by developing semi-aggregated systems, or systems with one or two satellites per orbital plane. Finally, we investigate several trades that are currently under consideration by NOAA and the DoD and make recommendations for future environmental monitoring systems in low-Earth orbit.Massachusetts Institute of Technology (Sandia Corporation Excellence in Engineering Graduate Fellowship)Skolkovo Institute of Science and Technolog

    Dynamic modelling of consumption patterns using LA-AIDS: : a comparative study of developed versus developing countries

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    Acknowledgements The authors would like to thank the anonymous referees and the editor of this journal for their constructive comments on an earlier version of the paper. We also thank Ms. Tanya Parker for editorial assistance. The authors also gratefully acknowledge the internal grants received from the Griffith Asia Institute and the COVID-19 Supplementary Funding Pool Scheme from Charles Darwin University to undertake this research. Funding Open Access funding enabled and organized by CAUL and its Member Institutions. This research did not receive any specific grant from funding agencies in the public, commercial or not-for-profit sectors.Peer reviewedPublisher PD

    Concatenated batch and continuous flow procedures for the upgrading of glycerol-derived aminodiols via N-acetylation and acetalization reactions

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    An unprecedented two-step sequence was designed by combining batch and continuous flow (CF) protocols for the upgrading of two aminodiol regioisomers derived from glycerol, i.e., 3-amino-1,2-propanediol and 2-amino-1,3-propanediol (serinol). Under batch conditions, at 80-90 \ub0C, both substrates were quantitatively converted into the corresponding amides through a catalystfree N-acetylation reaction mediated by an innocuous enol ester as isopropenyl acetate (iPAc). Thereafter, at 30-100 \ub0C and 1-10 atm, the amide derivatives underwent a selective CF-acetalisation in the presence of acetone and a solid acid catalyst, to afford the double-functionalized (amideacetal) products
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