23 research outputs found

    Relativistic Binaries in Globular Clusters

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    Galactic globular clusters are old, dense star systems typically containing 10\super{4}--10\super{7} stars. As an old population of stars, globular clusters contain many collapsed and degenerate objects. As a dense population of stars, globular clusters are the scene of many interesting close dynamical interactions between stars. These dynamical interactions can alter the evolution of individual stars and can produce tight binary systems containing one or two compact objects. In this review, we discuss theoretical models of globular cluster evolution and binary evolution, techniques for simulating this evolution that leads to relativistic binaries, and current and possible future observational evidence for this population. Our discussion of globular cluster evolution will focus on the processes that boost the production of hard binary systems and the subsequent interaction of these binaries that can alter the properties of both bodies and can lead to exotic objects. Direct {\it N}-body integrations and Fokker--Planck simulations of the evolution of globular clusters that incorporate tidal interactions and lead to predictions of relativistic binary populations are also discussed. We discuss the current observational evidence for cataclysmic variables, millisecond pulsars, and low-mass X-ray binaries as well as possible future detection of relativistic binaries with gravitational radiation.Comment: 88 pages, 13 figures. Submitted update of Living Reviews articl

    damage in primary hypertensive patients?

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    In this study, we aimed to compare Cystatin C (Cys C) with other traditional glomerular filtration rate (GFR) markers and to evaluate its superiority over them in detecting early renal involvement in patients with primary hypertension.Fifty-one primary hypertensive patients and 29 healthy control subjects, who were similar in terms of age and gender, were included in the study. In all subjects serum levels of Cys C, beta-2 microglobulin, serum creatinine (SCr), uric acid, BUN, albumin; 24 h urinary levels of protein (U-pro), albumin (U-alb) and creatinine were measured. The GFR was calculated according to Creatinine Clearance (CrCl), Cockcroft-Gault (CG) and Modification of Diet in Renal Disease (MDRD) formulas. The MDRD was used as the reference method. A GFR<80 mL/min/1.73 m 2 was considered as the lower cut-off limit.Mean levels of the serum parameters were found to be significantly higher in the patient group than they were in the control group (p < 0.05). Mean CrCl, CG, and MDRD levels were lower in patients than they were in controls but the difference was statistically significant for CG and MDRD. The serum parameter having the best correlation with MDRD was SCr (r = -0.760) in patients and Cys C (r = -0.622) in controls. However, in ROC analysis; the area under curve (AUC) for Cys C was found to be superior (AUC = 0.900) to the other markers. The CrCl was the parameter having the worst diagnostic efficiency (AUC = 0.598).As a conclusion, compared to other traditional markers, measurement of Cys C may be a better parameter to estimate GFR, especially to detect mild reductions of GFR in primary hypertensive patients

    Histologic, Histomorphometric, and Clinical Analysis of the Effects of Growth Factors in a Fibrin Network Used in Maxillary Sinus Augmentation

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    This randomized controlled clinical trial evaluated the effect of mineralized plasmatic matrix (MPM), comprised of synthetic graft and platelet concentrates, on new bone formation and volume stability over time in maxillary sinus lifting (MSL). Unilateral MSL was performed in 20 patients with either beta-tricalcium phosphate (beta-TCP) or MPM grafts (10 sinuses each). Six months postsurgery, specimens were obtained with a trephine bur prior to implant placement in 39 cases. Volumetric changes in sinus augmentation were analyzed between 1 week (T-I) and 6 months (T-II) postsurgery. Histomorphometric and histological analyses of biopsy samples revealed mean new bone percentages of 35.40% +/- 9.09% and 26.92% +/- 7.26% and residual graft particle areas of 23.13% +/- 6.16% and 32.25% +/- 8.48% in the MPM and beta-TCP groups, respectively (p 0.05). Graft reductions between baseline and 6-months postprocedure in the beta-TCP and MPM groups were 17.12% +/- 13.55% and 14.41% +/- 12.87%, respectively, with significant graft volume reduction observed in both groups (p 0.05). Thus, MPM, representing growth factors in a fibrin network, increases new bone formation and has acceptable volume stability in MSL procedure
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