24 research outputs found

    Introductory Chapter: Common Pitfalls and How to Overcome

    Get PDF

    A study of serum levels of B cell-attracting chemokine-13 (CXCL 13) and rheumatologic manifestations of chronic hepatitis C virus infection in a cohort of Egyptian patients

    Get PDF
    AbstractMany rheumatologic manifestations have been associated with Hepatitis C virus (HCV) infection including; arthralgia, myalgia, fatigue, fibromyalgia, vasculitis, and sicca syndrome. The relationship between emergence and persistence of intrahepatic or circulating B cell clonotypes and HCV infection is still unknown. However accumulating evidences indicate that certain chemokines play a critical role in providing the appropriate environment for activation and expansion of naïve lymphocytes, one of these chemokines is B cell-attracting chemokine-13 (CXCL13).CXCL13 is a major regulator of B-cell trafficking. This study evaluates circulating levels of CXCL13 protein in chronically HCV-infected Egyptian patients compared with healthy controls and its association with articular synovial hypertrophy. Rheumatic manifestations were present in 85% of patients; included fatigue (20%), arthralgia (the commonest manifestation) (65%), fibromyalgia (22%), myalgia (37%), Rayunad’s phenomenon (10%), peripheral neuropathy and arthritis (2.5%), and tendenitis (7.5). Cryoglobulins recorded in this study were of type II & III mixed cryoglobulins (MC) positive in 25% all of which showed positive rheumatoid factor (RF). Significant low levels of C3 and C4 were reported in the patient group. CXCL13 serum levels were significantly high in the patient group especially in the MC positive group compared to controls. The highest levels of CXCL13 were significantly associated with rheumatologic manifestations with or without mixed cryoglobulinemia and significantly associated with articular synovial hypertrophy

    Effect of Secondary Flows on Heat Transfer of a Gas Turbine Blade

    Get PDF
    This study presents experimental and numerical investigation for three-dimensional heat transfer characteristics in a turbine blade. An experimental setup was installed with a turbine cascade of five-blade channels. Blade heat transfer measurements were performed for the middle channel under uniform heat flux boundary conditions. Heat was supplied to the blades using twenty-nine electric heating strips cemented vertically on the outer surface of the blades. Distributions of heat transfer coefficient were obtained at three levels through blade height by measuring surface temperature distribution using thermocouples. To understand heat transfer characteristics, surface static pressure distributions on blade surface were also measured. Numerical investigation was performed as well to extend the investigation to locations other than those measured experimentally. Three-dimensional nonisothermal, turbulent flow was obtained by solving Reynolds averaged Navier-Stokes equations and energy equation. The shear stress transport model was employed to represent turbulent flow. It was found through this study that secondary flow generated by flow deflection increases heat transfer coefficient on the blade suction surface. Separation lines with high heat transfer coefficients were predicted numerically with good agreement with the experimental measurements

    The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance

    Get PDF
    INTRODUCTION Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic. RATIONALE We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs). RESULTS Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants. CONCLUSION Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century

    Essentials of Abdominal Ultrasound

    No full text
    Abdominal ultrasound is a bedside diagnostic tool that helps to discover many abdominal problems. It is a safe and painless procedure that has proven extremely useful for patient workup and diagnosis. This book illustrates the use of ultrasound for all the various organs of the abdomen. Each chapter covers a different organ and presents the latest knowledge and techniques of imaging. The content contained within is relevant across many specialties, including radiology and internal medicine, and is useful for physicians and medical residents and students alike

    Shyness and social phobia in Israeli Jewish vs Arab students

    No full text
    Abstract Background: Social anxiety disorder (SAD) has been repeatedly shown to be very prevalent in the Western society with prevalence rates of 10% or above. However, very few studies have been performed in the Middle East and in Arab countries. Methods: A total of 300 Israeli students participated in our study and were administered the Liebowitz Social Anxiety Scale (LSAS), the Cheek and Buss Shyness Questionnaire (CBSQ), and a sociodemographic questionnaire. Results: A total of 153 Jewish and 147 Arab students participated in the survey. Social anxiety disorder was found in 12.33% of the sample, according to the LSAS cutoff score of more than 60. The 2 subsamples had similar LSAS and CBSQ scores and similar SAD-positive rates (LSAS N60). Females had higher scores on the LSAS, as were those without a spouse and those who had been in psychological treatment. Based on a regression analysis, the significant predictors of the LSAS score were the CBSQ score and female sex. A very high correlation was found between the LSAS and the CBSQ scores. Conclusions: Although our sample is not representative of the whole Israeli population, we conclude that SAD and shyness were similarly prevalent in Jewish and Arab students in Israel. Social anxiety disorder scores were higher among females, those without a spouse, and those who received psychological treatment. Further studies on the clinical and cultural characteristics of SAD in Israeli subcultures would add to the growing body of knowledge on SAD in various cultures

    Point Biserial Correlation (PBC) for 1 to 20 clusters.

    No full text
    PBC was very similar for 3, 4 and 5 partitions. Therefore, we chose to build 4 clusters of patients (vertical dashed line). (PNG)</p
    corecore