Sodium enrichment in A-F type supergiants

We have investigated the nucleosynthesis of sodium (23Na) in stars of masses M = 5-19 M⊙ having solar-like initial chemical composition. The values obtained for the Na excess after the first dredge-up phase are in close agreement with recent observations suggesting a moderate Na excess in F-type supergiants. We also found a positive correlation between the overabundance factors [N/H] and [Na/H] which seems to indicate that Na enrichment originates from the Ne-Na cycle operating simultaneously with the CNO tri-cycle in these stars. We emphasize that our results were obtained on the basis of standard physical assumptions in the stellar model calculations, but with updated reaction rates for the reactions involved in the Ne-Na cycle which are presented in this work

The effect of the 14N(p, γ)15O reaction on the blue loops in intermediate-mass stars

We present stellar evolutionary sequences of stars in the mass range 5-12 M , having solar-like initial composition. The stellar models are obtained using updated input physics, including recent rates of thermonuclear reactions. We investigate the effects of a modification of the 14N(p, γ) 15O reaction rate, as suggested by recent evaluations, on the formation and extension of the blue loops encountered during the evolution of the stars in the above mass range. We find that a reduced 14N(p, γ)15O rate, as described in the text, has a striking impact on the physical conditions of burning and mixing during shell hydrogen burning when the blue loops are formed. In particular, we find that the efficiency of shell hydrogen burning is crucial for the formation of an extended blue loop. We show that a significantly reduced 14N(p, γ)15O rate affects severely the extension of the blue loops and the time spent by the star in the blue part of the Hertzsprung-Russell diagram in the mass range 5-7 M if the treatment of convection is based on the Schwarzschild criterion only. In this case, envelope overshooting helps to restore well-extended blue loops as supported by the observations of the Cepheid stars. If core overshooting is included during the core hydrogen and core helium burning phases, the loop formation and its properties depend on how this overshooting is treated for a given stellar mass range, as well as on its efficiency

Global surveillance of cancer survival 1995-2009: analysis of individual data for 25,676,887 patients from 279 population-based registries in 67 countries (CONCORD-2)

BACKGROUND: Worldwide data for cancer survival are scarce. We aimed to initiate worldwide surveillance of cancer survival by central analysis of population-based registry data, as a metric of the effectiveness of health systems, and to inform global policy on cancer control. METHODS: Individual tumour records were submitted by 279 population-based cancer registries in 67 countries for 25·7 million adults (age 15-99 years) and 75,000 children (age 0-14 years) diagnosed with cancer during 1995-2009 and followed up to Dec 31, 2009, or later. We looked at cancers of the stomach, colon, rectum, liver, lung, breast (women), cervix, ovary, and prostate in adults, and adult and childhood leukaemia. Standardised quality control procedures were applied; errors were corrected by the registry concerned. We estimated 5-year net survival, adjusted for background mortality in every country or region by age (single year), sex, and calendar year, and by race or ethnic origin in some countries. Estimates were age-standardised with the International Cancer Survival Standard weights. FINDINGS: 5-year survival from colon, rectal, and breast cancers has increased steadily in most developed countries. For patients diagnosed during 2005-09, survival for colon and rectal cancer reached 60% or more in 22 countries around the world; for breast cancer, 5-year survival rose to 85% or higher in 17 countries worldwide. Liver and lung cancer remain lethal in all nations: for both cancers, 5-year survival is below 20% everywhere in Europe, in the range 15-19% in North America, and as low as 7-9% in Mongolia and Thailand. Striking rises in 5-year survival from prostate cancer have occurred in many countries: survival rose by 10-20% between 1995-99 and 2005-09 in 22 countries in South America, Asia, and Europe, but survival still varies widely around the world, from less than 60% in Bulgaria and Thailand to 95% or more in Brazil, Puerto Rico, and the USA. For cervical cancer, national estimates of 5-year survival range from less than 50% to more than 70%; regional variations are much wider, and improvements between 1995-99 and 2005-09 have generally been slight. For women diagnosed with ovarian cancer in 2005-09, 5-year survival was 40% or higher only in Ecuador, the USA, and 17 countries in Asia and Europe. 5-year survival for stomach cancer in 2005-09 was high (54-58%) in Japan and South Korea, compared with less than 40% in other countries. By contrast, 5-year survival from adult leukaemia in Japan and South Korea (18-23%) is lower than in most other countries. 5-year survival from childhood acute lymphoblastic leukaemia is less than 60% in several countries, but as high as 90% in Canada and four European countries, which suggests major deficiencies in the management of a largely curable disease. INTERPRETATION: International comparison of survival trends reveals very wide differences that are likely to be attributable to differences in access to early diagnosis and optimum treatment. Continuous worldwide surveillance of cancer survival should become an indispensable source of information for cancer patients and researchers and a stimulus for politicians to improve health policy and health-care systems

Evolution of massive stars

VizieR online Data Catalogue associated with article published in journal Astronomical Journal (AAS) with title \u27Evolution of massive stars up to the end of central oxygen burning.\u27 (bibcode: 2004ApJ...611..452E

Comments on the Evolution of Massive Stars

We describe in a brief form present results we have obtained from a careful and up to date study of the evolution of massive stars including their advanced evolutionary phases beyond the oxygen burning phase. We describe the effects of mass loss, treatment of convection in inhomogeneous stellar layers and the rate of the 12C(α, γ)16O reaction on the properties of stellar models in the interesting case of a 25 M๏ star of solar-like initial metallicity

Migratory Birds as Disseminators of Avian Influenza Viruses to Egypt (2003 – 2023)

Migratory birds are considered a vessel for preserving and transmitting microbes, which contribute with great force in transporting them from one place to another over long distances in the world. This would contribute to the emergence of disease pandemics globally and the most obvious example is the avian influenza (AI) epidemics over time. The most famous recent scenario is the AI pandemic that began in Hong Kong in 1990s. Natural resistance to AI helps migratory birds retain avian influenza viruses (AIVs) for long periods and transfer them from their source to many other countries during migration paths. Accordingly, they serve as a vector for the maintenance and introduction of both highly pathogenic and low pathogenic avian influenza (HPAI and LPAI). Through this study, the subtypes of high- and low-pathogenic avian influenza viruses found in migratory and wild birds in Egypt were identified, and the most important species of implicated birds were recognized since 1970s tell now. In the view of geoepidemiology of AIVs transmitted by migratory birds, we highlighted the main entry, gathering places and movement routes encountered either with free-living or domesticated birds. By reviewing the outcomes of previous studies over the past two decades, a total of 108 AIVs including 70 of the LPAI and 38 of the HPAI were isolated from migratory and free-living birds. Migratory birds topped the list with 91% of the LPAI and 79% of the HPAI. Interestingly, Damietta province had the highest rates of virus isolation; 81.3% and 40% for LPAI and HPAI viruses respectively, followed by Sharkia particularly in HPAIV (26.7) and both borders are with Lake Manzala. Two Anseriformes-migratory birds; Northern shoveler & Green-winged teal harbored more than 50% of the isolated AIVs. Therefore, we call for conducting annual screening of AIVs in spring and fall. Focusing on Anseriformes and recently proposed quails as vessels for AIVs’ mutations mainly in northeast Lakes’ border provinces for early detection and quick intervene and avoid their spread became an urgent need

Migratory Birds as Disseminators of Avian Influenza Viruses to Egypt (2003 – 2023)

Migratory birds are considered a vessel for preserving and transmitting microbes, which contribute with great force in transporting them from one place to another over long distances in the world. This would contribute to the emergence of disease pandemics globally and the most obvious example is the avian influenza (AI) epidemics over time. The most famous recent scenario is the AI pandemic that began in Hong Kong in 1990s. Natural resistance to AI helps migratory birds retain avian influenza viruses (AIVs) for long periods and transfer them from their source to many other countries during migration paths. Accordingly, they serve as a vector for the maintenance and introduction of both highly pathogenic and low pathogenic avian influenza (HPAI and LPAI). Through this study, the subtypes of high- and low-pathogenic avian influenza viruses found in migratory and wild birds in Egypt were identified, and the most important species of implicated birds were recognized since 1970s tell now. In the view of geoepidemiology of AIVs transmitted by migratory birds, we highlighted the main entry, gathering places and movement routes encountered either with free-living or domesticated birds. By reviewing the outcomes of previous studies over the past two decades, a total of 108 AIVs including 70 of the LPAI and 38 of the HPAI were isolated from migratory and free-living birds. Migratory birds topped the list with 91% of the LPAI and 79% of the HPAI. Interestingly, Damietta province had the highest rates of virus isolation; 81.3% and 40% for LPAI and HPAI viruses respectively, followed by Sharkia particularly in HPAIV (26.7) and both borders are with Lake Manzala. Two Anseriformes-migratory birds; Northern shoveler & Green-winged teal harbored more than 50% of the isolated AIVs. Therefore, we call for conducting annual screening of AIVs in spring and fall. Focusing on Anseriformes and recently proposed quails as vessels for AIVs’ mutations mainly in northeast Lakes’ border provinces for early detection and quick intervene and avoid their spread became an urgent need

Thiazole derivatives as inhibitors of cyclooxygenases in vitro and in vivo

Cyclooxygenases (COXs) are important membrane-bound heme containing enzymes important in platelet activation and inflammation. COX-1 is constitutively expressed in most cells whereas COX-2 is an inducible isoform highly expressed in inflammatory conditions. Studies have been carried out to evaluate thiazole derivatives as anti-inflammatory molecules. In this study, we investigated the in vitro and in vivo effects of two novel thiazole derivatives compound 1 (N-[4-(4-hydroxy-3-methoxyphenyl)-1,3-thiazol-2-yl] acetamide) and compound 2 (4-(2-amino-1,3-thiazol-4-yl)-2-methoxyphenol) on prostaglandin E2 (PGE2) production and COX activity in inflammatory settings. Our results reveal a potent inhibition of both compound 1 (IC50 9.01±0.01 μM) and 2 (IC50 11.65±6.20 μM) (Mean±S.E.M.) on COX-2-dependent PGE2 production. We also determined whether COX-1 activity was inhibited. Using cells stably over-expressing COX-1 and human blood platelets, we showed that compound 1 is a specific inhibitor of COX-1 with IC50 (5.56×10-8±2.26×10-8 μM), whereas compound 2 did not affect COX-1. Both compounds exhibit anti-inflammatory effect in the dorsal air pouch model of inflammation as shows by inhibition of PGE2 secretion. Modeling analysis of docking in the catalytic site of COX-1 or COX-2 further confirmed the difference in the effect of these two compounds. In conclusion, this study contributes to the design of new anti-inflammatory agents and to the understanding of cyclooxygenase inhibition by thiazole.SCOPUS: ar.jinfo:eu-repo/semantics/publishe