1,701 research outputs found

    Spectral clustering for TRUS images

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    BACKGROUND: Identifying the location and the volume of the prostate is important for ultrasound-guided prostate brachytherapy. Prostate volume is also important for prostate cancer diagnosis. Manual outlining of the prostate border is able to determine the prostate volume accurately, however, it is time consuming and tedious. Therefore, a number of investigations have been devoted to designing algorithms that are suitable for segmenting the prostate boundary in ultrasound images. The most popular method is the deformable model (snakes), a method that involves designing an energy function and then optimizing this function. The snakes algorithm usually requires either an initial contour or some points on the prostate boundary to be estimated close enough to the original boundary which is considered a drawback to this powerful method. METHODS: The proposed spectral clustering segmentation algorithm is built on a totally different foundation that doesn't involve any function design or optimization. It also doesn't need any contour or any points on the boundary to be estimated. The proposed algorithm depends mainly on graph theory techniques. RESULTS: Spectral clustering is used in this paper for both prostate gland segmentation from the background and internal gland segmentation. The obtained segmented images were compared to the expert radiologist segmented images. The proposed algorithm obtained excellent gland segmentation results with 93% average overlap areas. It is also able to internally segment the gland where the segmentation showed consistency with the cancerous regions identified by the expert radiologist. CONCLUSION: The proposed spectral clustering segmentation algorithm obtained fast excellent estimates that can give rough prostate volume and location as well as internal gland segmentation without any user interaction

    Isolation and screening of some medically important fungi from indoor environment: Studying the effect of some environmental and chemical factors on their growth and spore adhesion

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    Isolation of some pathogenic fungi from indoor environment that may cause diseases to athletes was the goal of this work. The effect of different cloth materials and some environmental factors on the growth and adhesion of the isolated fungi as Aspergillus sydowii, Cochliobolus hawaiiensis, Cochliobolus lunatus, Epicoccum nigrum, Nigrospora oryzae, Penicillium aurantiogriseum, Cladosporium sphaerospermum, Aspergillus niger, Cochliobolus australiensis, Stemphylium botryosum, Alternaria. alternata, Fusarium chlamydosporum, Aspergillus flavus and Aspergillus versicolor was investigated. By studying the effect of different cloth materials, at temperatures (18, 25 and 35°C) and at pH values (4, 5.6, 8), it was concluded that cloth material, 74% cotton - 25% polyester- 1% elasthan (C.P.E) was the lowest in susceptibility to fungal attack. The fungal pathogens growth was favored at 35°C and pH 8 after two days of incubation while, after five days the growth was favored at 25 and 35°C at pH 5.6 and pH 8. Alter. alternata and A. flavus were selected for studying their spore adhesion on different cloth material samples. Also, their sensitivity for detergents and drugs on different cloth material samples was carried out.Key words: Pathogenic fungi, athletes, fungal adhesion, antimicrobial activity

    Occurrence and overlap of natural disasters, complex emergencies and epidemics during the past decade (1995–2004)

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    BACKGROUND: The fields of expertise of natural disasters and complex emergencies (CEs) are quite distinct, with different tools for mitigation and response as well as different types of competent organizations and qualified professionals who respond. However, natural disasters and CEs can occur concurrently in the same geographic location, and epidemics can occur during or following either event. The occurrence and overlap of these three types of events have not been well studied. METHODS: All natural disasters, CEs and epidemics occurring within the past decade (1995–2004) that met the inclusion criteria were included. The largest 30 events in each category were based on the total number of deaths recorded. The main databases used were the Emergency Events Database for natural disasters, the Uppsala Conflict Database Program for CEs and the World Health Organization outbreaks archive for epidemics. ANALYSIS: During the past decade, 63% of the largest CEs had ≥1 epidemic compared with 23% of the largest natural disasters. Twenty-seven percent of the largest natural disasters occurred in areas with ≥1 ongoing CE while 87% of the largest CEs had ≥1 natural disaster. CONCLUSION: Epidemics commonly occur during CEs. The data presented in this article do not support the often-repeated assertion that epidemics, especially large-scale epidemics, commonly occur following large-scale natural disasters. This observation has important policy and programmatic implications when preparing and responding to epidemics. There is an important and previously unrecognized overlap between natural disasters and CEs. Training and tools are needed to help bridge the gap between the different type of organizations and professionals who respond to natural disasters and CEs to ensure an integrated and coordinated response

    The transport of nanoparticles in subsurface with fractured, anisotropic porous media: Numerical simulations and parallelization

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    The flow of fluids through fractured porous media has been an important topic in the research of subsurface flow. The several orders of magnitude in size between the fractures and the rock matrix causes difficulties for simulating such flow scenario. The fluid velocities in fractures are also several orders of magnitude higher than that in the rock matrix due to high permeability and porosity. If there exists pollutant such as nanoparticles in the fluids, the pollutant may be transported rapidly and the rock matrix’s properties near the fractures are hence changed. In this research, we simulate the transport phenomena of nanoparticles in the fluid flow through fractured porous media. The permeability fields which contain different anisotropy angles are considered in the simulation. Fractures are represented explicitly by volumetric grid cells and the numerical algorithm is parallelized in order to reduce the simulation time. We investigate the effect of the appearance of fractures and rotated anisotropy on the transport of nanoparticles, particles deposition, entrapment and detachment. The results show that flow directions are affected by the direction of anisotropy and the transport of nanoparticles in the fractures is significantly faster than that in rock matrix due to high fluid velocities. The direction of anisotropy distorted the pressure field and changed the fluid flow directions, which determined the time needed for the pollutant front to reach the fractures. The parallel efficiency of the overall algorithm is also discussed and the experimental results show that it is deeply affected by the performance of the multigrid solver

    Catechol-O-Methyltransferase Expression and 2-Methoxyestradiol Affect Microtubule Dynamics and Modify Steroid Receptor Signaling in Leiomyoma Cells

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    CONTEXT: Development of optimal medicinal treatments of uterine leiomyomas represents a significant challenge. 2-Methoxyestradiol (2ME) is an endogenous estrogen metabolite formed by sequential action of CYP450s and catechol-O-methyltransferase (COMT). Our previous study demonstrated that 2ME is a potent antiproliferative, proapoptotic, antiangiogenic, and collagen synthesis inhibitor in human leiomyomas cells (huLM). OBJECTIVES: Our objectives were to investigate whether COMT expression, by the virtue of 2ME formation, affects the growth of huLM, and to explore the cellular and molecular mechanisms whereby COMT expression or treatment with 2ME affect these cells. RESULTS: Our data demonstrated that E(2)-induced proliferation was less pronounced in cells over-expressing COMT or treated with 2ME (500 nM). This effect on cell proliferation was associated with microtubules stabilization and diminution of estrogen receptor alpha (ERalpha) and progesterone receptor (PR) transcriptional activities, due to shifts in their subcellular localization and sequestration in the cytoplasm. In addition, COMT over expression or treatment with 2ME reduced the expression of hypoxia-inducible factor -1alpha (HIF-1 alpha) and the basal level as well as TNF-alpha-induced aromatase (CYP19) expression. CONCLUSIONS: COMT over expression or treatment with 2ME stabilize microtubules, ameliorates E(2)-induced proliferation, inhibits ERalpha and PR signaling, and reduces HIF-1 alpha and CYP19 expression in human uterine leiomyoma cells. Thus, microtubules are a candidate target for treatment of uterine leiomyomas. In addition, the naturally occurring microtubule-targeting agent 2ME represents a potential new therapeutic for uterine leiomyomas

    Long term soil moisture mapping over the Tibetan plateau using Special Sensor Microwave/Imager

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    This paper discusses soil moisture retrievals over the Tibetan Plateau from brightness temperature (TB's) observed by the Special Sensor Microwave Imagers (SSM/I's) during the warm seasons of the period from July 1987 to December 2008. The Fundamental Climate Data Record (FCDR) of F08, F11 and F13 SSM/I satellites by the Precipitation Research Group of Colorado State University is used for this study. A soil moisture retrieval algorithm is developed based on a radiative transfer model that simulates top-of-atmosphere TB's whereby effects of atmosphere are calculated from near-surface forcings obtained from a bias-corrected dataset. Validation of SSM/I retrievals against in situ measurements for a two-and-half year period (225 matchups) gives a Root Mean Squared Error of 0.046 m3 m−3. The agreement between retrievals and Noah simulations from the Global Land Data Assimilation System is investigated to further provide confidence in the reliability of SSM/I retrievals at the Plateau-scale. Normalised soil moisture anomalies (N) are computed on a warm seasonal (May–October) and on a monthly basis to analyse the trends present within the products available from July 1987 to December 2008. The slope of linear regression functions between N and time is used to quantify the trends. Both the warm season and monthly N indicate severe wettings of 0.8 to almost 1.6 decade−1 in the centre of the Plateau. Correlations are found by the trend with elevation for the warm season as a whole and the individual months May, September and October. The observed wetting of the Tibetan Plateau agrees with recent findings on permafrost retreat, precipitation increase and potential evapotranspiration decline

    Risk factors for severe outcomes in patients with systemic vasculitis & COVID‐19: a bi‐national registry‐based cohort study

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    OBJECTIVE: COVID-19 is a novel infectious disease with a broad spectrum of clinical severity. Patients with systemic vasculitis have an increased risk of serious infections and so may be at risk of severe outcomes following COVID-19. It is important to establish the risk factors for severe COVID-19 outcomes in these patients, including the impact of immunosuppressive therapies. METHODS: A multi-centre cohort was developed through the participation of centres affiliated with national UK and Ireland vasculitis registries. Clinical characteristics and outcomes were described. Logistic regression was used to evaluate associations between potential risk factors and severe COVID-19 outcome, defined as a requirement for advanced oxygen therapy, invasive ventilation, or death. RESULTS: Sixty-five cases of patients with systemic vasculitis who developed COVID-19 were reported (median age 70 years, 49% female) of whom 25 (38%) experienced a severe outcome. Most cases (55/65, 85%) had ANCA-associated vasculitis (AAV). Almost all patients required hospitalization (59/65, 91%), 7 patients (11%) were admitted to intensive care and 18 patients (28%) died. Background glucocorticoid therapy was associated with severe outcome (adjusted odds ratio [aOR] 3.7 (1.1-14.9, p=0.047)) as was comorbid respiratory disease (aOR 7.5 (1.9-38.2, p=0.006)). Vasculitis disease activity and non-glucocorticoid immunosuppression were not associated with severe outcome. CONCLUSION: In patients with systemic vasculitis, glucocorticoid use at presentation and comorbid respiratory disease were associated with severe outcomes in COVID-19. These data can inform clinical decision making relating to risk of severe COVID-19 in this vulnerable patient group

    Recommendations for the management of secondary hypogammaglobulinaemia due to B cell targeted therapies in autoimmune rheumatic diseases

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    OBJECTIVES: The association of B cell targeted therapies with development of hypogammaglobulinaemia and infection is increasingly recognized. Our aim was to develop consensus recommendations for immunoglobulin replacement therapy for management of hypogammaglobulinaemia following B cell targeted therapies in autoimmune rheumatic diseases. // METHODS: A modified Delphi exercise involved a 17-member Taskforce committee, consisting of immunologists, rheumatologists, nephrologists, haematologists, a gastroenterologist, an immunology specialist nurse and a patient representative. The first round identified the most pertinent topics to address in the recommendations. A search string was agreed upon for the identification of publications in PubMed focusing on these areas, for a systematic literature review. Original data was presented from this review to the Taskforce committee. Recommendations from the British Society for Rheumatology, the UK Department of Health, EULAR, the ACR, and the American Academy of Allergy, Asthma, and Immunology were also reviewed. The evidence was discussed in a face-to-face meeting to formulate recommendation statements. The levels of evidence and statements were graded according to Scottish Intercollegiate Guidelines Network methodology. // RESULTS: Three overarching principles, eight recommendation statements and a research agenda were formulated. The Taskforce committee voted on these statements, achieving 82–100% agreement for each recommendation. The strength of the recommendations was restricted by the low quality of the available evidence, with no randomized controlled trial data. The recommendations cover risk factors, monitoring, referral for hypogammaglobulinaemia; indications, dosage and discontinuation of immunoglobulin replacement therapy. // CONCLUSION: These are the first recommendations specifically formulated for B cell targeted therapies related to hypogammaglobulinaemia in autoimmune rheumatic diseases. The recommendations are to aid health-care professionals with clinical decision making for patients with hypogammaglobulinaemia
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