1,747 research outputs found

    A review of necrotising fasciitis in the extremities

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    Objective: To review currently available evidence on the epidemiology and methods of management for necrotising fasciitis, with particular reference to Hong Kong. Data sources and study selection: Medline, PubMed, and Cochrane Library searches of local and internationally published English language journals, from 1990 to July 2008 using the terms 'necrotising fasciitis', 'Hong Kong', 'diagnosis', 'epidemiology', 'vibrio', 'streptococci', 'clostridia', and 'management'. Data extraction: All articles involving necrotising fasciitis in Hong Kong were included in the review. Data synthesis: The incidence of necrotising fasciitis in Hong Kong and around the world has been increasing. This rapidly progressive infection is a major cause of concern, due to its high morbidity and mortality. Up to 93% of affected patients at our hospital were admitted to the Intensive Care Unit and many still died from septic complications, such as pneumonia and multi-organ failure. Radical debridements in the form of amputations and disarticulations were considered vital in 46% of the patients. Early recognition and treatment remain the most important factors influencing survival. Yet, early diagnosis of the condition is difficult due to its similarities with many other soft tissue disorders such as cellulitis. Repeated surgical debridement or incisional drainage continues to be essential for the survival of sufferers from necrotising fasciitis. Many authorities have reported that carrying out the first fasciotomy and radical debridement within 24 hours of symptom onset was associated with significantly improved survival, which also emphasises the importance of early diagnosis. Conclusion: Clinicians must adopt a high index of suspicion for necrotising fasciitis. Empirical antibiotics must be started early and repeated physical examinations should be performed, while maintaining a low threshold for tissue biopsy and surgery. The timing of the first fasciotomy and radical debridement within a window of 24 hours from symptom onset is associated with significantly improved survival.published_or_final_versio

    Spatial and temporal variations of mercury in sediments from Victoria Harbour, Hong Kong

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    Author name used in this publication: Carman C. M. IpAuthor name used in this publication: Chole W. Y. Tang2006-2007 > Academic research: refereed > Publication in refereed journalAccepted ManuscriptPublishe

    The spatial and temporal distribution of heavy metals in sediments of Victoria Harbour, Hong Kong

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    Author name used in this publication: Chloe Wing-yee TangAuthor name used in this publication: Carman Ching-man Ip2007-2008 > Academic research: refereed > Publication in refereed journalAccepted ManuscriptPublishe

    A particle swarm optimization based memetic algorithm for dynamic optimization problems

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    Copyright @ Springer Science + Business Media B.V. 2010.Recently, there has been an increasing concern from the evolutionary computation community on dynamic optimization problems since many real-world optimization problems are dynamic. This paper investigates a particle swarm optimization (PSO) based memetic algorithm that hybridizes PSO with a local search technique for dynamic optimization problems. Within the framework of the proposed algorithm, a local version of PSO with a ring-shape topology structure is used as the global search operator and a fuzzy cognition local search method is proposed as the local search technique. In addition, a self-organized random immigrants scheme is extended into our proposed algorithm in order to further enhance its exploration capacity for new peaks in the search space. Experimental study over the moving peaks benchmark problem shows that the proposed PSO-based memetic algorithm is robust and adaptable in dynamic environments.This work was supported by the National Nature Science Foundation of China (NSFC) under Grant No. 70431003 and Grant No. 70671020, the National Innovation Research Community Science Foundation of China under Grant No. 60521003, the National Support Plan of China under Grant No. 2006BAH02A09 and the Ministry of Education, science, and Technology in Korea through the Second-Phase of Brain Korea 21 Project in 2009, the Engineering and Physical Sciences Research Council (EPSRC) of UK under Grant EP/E060722/01 and the Hong Kong Polytechnic University Research Grants under Grant G-YH60

    Stemness and chemoresistance in epithelial ovarian carcinoma cells under shear stress

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    One of greatest challenges to the successful treatment of cancer is drug resistance. An exciting approach is the eradication of cancer stem cells (CSCs). However, little is known about key signals regulating the formation and expansion of CSCs. Moreover, lack of a reliable predictive preclinical model has been a major obstacle to discover new cancer drugs and predict their clinical activity. Here, in ovarian cancer, a highly chemoresistant tumor that is rapidly fatal, we provide the first evidence demonstrating the causal involvement of mechanical stimulus in the CSC phenotype using a customizable microfluidic platform and three-dimensional spheroids, which most closely mimic tumor behavior. We found that ovarian cancer cells significantly acquired the expression of epithelial-to-mesenchymal transition and CSC markers and a remarkable chemoresistance to clinically relevant doses of frontline chemotherapeutic drugs cisplatin and paclitaxel when grown under fluid shear stress, which corroborates with the physiological attainable levels in the malignant ascites, but not under static condition. Furthermore, we uncovered a new link of microRNA-199a-3p, phosphatidylinositol 3-kinase/Akt, and multidrug transporter activation in shear stress-induced CSC enrichment. Our findings shed new light on the significance of hydrodynamics in cancer progression, emphasizing the need of a flow-informed framework in the development of therapeutics

    Bismuth oxyhalides: synthesis, structure and photoelectrochemical activity

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    We report the synthesis and photoelectrochemical assessment of phase pure tetragonal matlockite structured BiOX (where X = Cl, Br, I) films. The materials were deposited using aerosol-assisted chemical vapour deposition. The measured optical bandgaps of the oxyhalides, supported by density functional theory calculations, showed a red shift with the increasing size of halide following the binding energy of the anion p-orbitals that form the valence band. Stability and photoelectrochemical studies carried out without a sacrificial electron donor showed the n-type BiOBr film to have the highest photocurrent reported for BiOBr in the literature to date (0.3 mA cm−2 at 1.23 V vs. RHE), indicating it is an excellent candidate for solar fuel production with a very low onset potential of 0.2 V vs. RHE. The high performance was attributed to the preferred growth of the film in the [011] direction, as shown by X-ray diffraction, leading to internal electric fields that minimize charge carrier recombination

    The Ginger-shaped Asteroid 4179 Toutatis: New Observations from a Successful Flyby of Chang'e-2

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    On 13 December 2012, Chang'e-2 conducted a successful flyby of the near-Earth asteroid 4179 Toutatis at a closest distance of 770 ±\pm 120 meters from the asteroid's surface. The highest-resolution image, with a resolution of better than 3 meters, reveals new discoveries on the asteroid, e.g., a giant basin at the big end, a sharply perpendicular silhouette near the neck region, and direct evidence of boulders and regolith, which suggests that Toutatis may bear a rubble-pile structure. Toutatis' maximum physical length and width are (4.75 ×\times 1.95 km) ±\pm10%\%, respectively, and the direction of the +zz axis is estimated to be (250±\pm5^\circ, 63±\pm5^\circ) with respect to the J2000 ecliptic coordinate system. The bifurcated configuration is indicative of a contact binary origin for Toutatis, which is composed of two lobes (head and body). Chang'e-2 observations have significantly improved our understanding of the characteristics, formation, and evolution of asteroids in general.Comment: 21 pages, 3 figures, 1 tabl
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