75 research outputs found

    Mammographic criteria for determining the diagnostic value of microcalcifications in the detection of early breast cancer

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    Objective: To evaluate the importance of microcalcifications in the detection of breast carcinoma in conventional mammography.Methods: This prospective study was carried out at Aga Khan University Hospital (AKUH). Mammograms of 68 patients with microcalcifications were evaluated. Craniocaudal and oblique views of both breasts were acquired on routine basis with cone compression and magnified views when required.Results: Among 68 patients with microcalcifications, 61 (89%) had clustered microcalcifications while 7 patients (10.29%) had scattered microcalcifications. Microcalcifications can occur in benign and malignant diseases. While evaluating clustered microcalcifications, few criteria have been established to determine malignant clustered microcalcifications, these include specific and nonspecific criteria. Among specific and statistically significant criteria for malignant microcalcifications, which were identified in this study, were irregularity of size, irregularity of density, linear or branched shape and Le Gal\u27s type V distribution. In a cluster total number of \u3e30 microcalcifications and at least 10 microcalcifications/cm2 of a cluster are also important in diagnosing a malignant cluster, but are included in nonspecific criteria because they can be present in benign diseases also. Scattered bilateral microcalcifications are usually present in benign breast diseases, but in this study, two patients with breast cancer had profuse bilateral scattered microcalcifications.CONCLUSION: This study shows that specific and statistically significant criteria for malignant microcalcifications, are irregularity of size, irregularity of density, linear or branched shape and Le Gal\u27s type V distribution. Scattered bilateral microcalcifications are usually present in benign breast diseases, but irregular shape and development of new calcifications among diffusely scattered bilateral calcifications, on follow up study, should also raise suspicion for being malignant

    Hybrid particle swarm optimization for robust digital image watermarking

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    This paper presents an image watermarking algorithm for the optimization between robustness and transparency which is recently considered as one of the most challenging issues. The novelty is to associate the Hybrid Particle Swarm Optimization (HPSO), instead of a single optimization, as a model with singular value decomposition (SVD). To embed and extract the watermark, the singular values of the blocked host image are modified according to the watermark and scaling factors. A series of training patterns are constructed by employing between two images. Moreover, the work takes accomplishing maximum robustness and transparency into consideration. HPSO method is used to estimate the multiple parameters involved in the model. Simulation results demonstrated that the proposed scheme can effectively improve the quality of the watermarked image and resist common image manipulations such as adding noise, resizing compression, tempering, etc. and some geometric attacks

    Serology based disease status of Pakistani population infected with Hepatitis B virus

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    <p>Abstract</p> <p>Background</p> <p>The infection rate of hepatitis B virus is continuously increasing in Pakistan. Therefore, a comprehensive study of epidemiological data is the need of time.</p> <p>Methods</p> <p>A total of 1300 individuals were screened for HBV infection markers including HBsAg, anti-HBsAg, HBeAg and anti-HBcAg. The association of these disease indicators was compared with patients' epidemiological characteristics like age, socio-economic status and residential area to analyze and find out the possible correlation among these variables and the patients disease status.</p> <p>Results</p> <p>52 (4%) individuals were found positive for HBsAg with mean age 23.5 ± 3.7 years. 9.30%, 33.47% and 12% individuals had HBeAg, antibodies for HBsAg, and antibodies for HBcAg respectively. HBsAg seropositivity rate was significantly associated (<it>p </it>= 0.03) with the residing locality indicating high infection in rural areas. Antibodies titer against HBsAg decreased with the increasing age reflecting an inverse correlation.</p> <p>Conclusion</p> <p>Our results indicate high prevalence rate of Hepatitis B virus infection and nationwide vaccination campaigns along with public awareness and educational programs are needed to be practiced urgently.</p

    Molecular epidemiology of Hepatitis B virus genotypes in Pakistan

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    <p>Abstract</p> <p>Background</p> <p>Eight genotypes of Hepatitis B virus designated A-H, have been known but in Pakistan, no such data is available on the prevalent HBV genotypes. Therefore, the subject study was conducted to determine HBV genotypes in the indigenous Pakistani population.</p> <p>Methods</p> <p>A total of 690 individuals were enrolled for HBV screening with EIA and nested PCR. Positive samples were further analyzed to determine HBV genotypes (A-F) by multiplex-PCR using type specific primers.</p> <p>Results</p> <p>110 (15.94%) individuals were positive for HBV, including 64% males and 36% females. Out of these, 66 samples (65.34%) were classified into genotype D, 27 (26.73%) were of genotype B while 5(4.95%) had genotype A. In 3 (2.98%) samples, multiple genotypes were detected (genotype A+B; 2(1.99%) and genotypes B+D; 1(0.99%). Nine (8.18%) samples remained untyable.</p> <p>Conclusion</p> <p>In Asia, genotypes B and C are the most prevalent but our study reveals that genotype D is predominant and HBV infection constitutes a significant health problem in Pakistan.</p

    Dark sectors 2016 Workshop: community report

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    This report, based on the Dark Sectors workshop at SLAC in April 2016, summarizes the scientific importance of searches for dark sector dark matter and forces at masses beneath the weak-scale, the status of this broad international field, the important milestones motivating future exploration, and promising experimental opportunities to reach these milestones over the next 5-10 years

    Colorization and Automated Segmentation of Human T2 MR Brain Images for Characterization of Soft Tissues

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    Characterization of tissues like brain by using magnetic resonance (MR) images and colorization of the gray scale image has been reported in the literature, along with the advantages and drawbacks. Here, we present two independent methods; (i) a novel colorization method to underscore the variability in brain MR images, indicative of the underlying physical density of bio tissue, (ii) a segmentation method (both hard and soft segmentation) to characterize gray brain MR images. The segmented images are then transformed into color using the above-mentioned colorization method, yielding promising results for manual tracing. Our color transformation incorporates the voxel classification by matching the luminance of voxels of the source MR image and provided color image by measuring the distance between them. The segmentation method is based on single-phase clustering for 2D and 3D image segmentation with a new auto centroid selection method, which divides the image into three distinct regions (gray matter (GM), white matter (WM), and cerebrospinal fluid (CSF) using prior anatomical knowledge). Results have been successfully validated on human T2-weighted (T2) brain MR images. The proposed method can be potentially applied to gray-scale images from other imaging modalities, in bringing out additional diagnostic tissue information contained in the colorized image processing approach as described

    The 17th International Congress on Infectious Diseases workshop on developing infection prevention and control resources for low- and middle-income countries

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    Hospital-acquired infections (HAIs) are a major concern to healthcare systems around the world. They are associated with significant morbidity and mortality, in addition to increased hospitalization costs. Recent outbreaks, including those caused by the Middle East respiratory syndrome coronavirus and Ebola virus, have highlighted the importance of infection control. Moreover, HAIs, especially those caused by multidrug-resistant Gram-negative rods, have become a top global priority. Although adequate approaches and guidelines have been in existence for many years and have often proven effective in some countries, the implementation of such approaches in low- and middle-income countries (LMICs) is often restricted due to limited resources and underdeveloped infrastructure. While evidence-based infection prevention and control (IPC) principles and practices are universal, studies are needed to evaluate simplified approaches that can be better adapted to LMIC needs, in order to guide IPC in practice. A group of experts from around the world attended a workshop held at the 17th International Congress on Infectious Diseases in Hyderabad, India in March 2016, to discuss the existing IPC practices in LMICs, and how best these can be improved within the local context
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