49 research outputs found

    Blazar Optical Variability in the Palomar-QUEST Survey

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    We study the ensemble optical variability of 276 FSRQs and 86 BL Lacs in the Palomar-QUEST Survey with the goal of searching for common fluctuation properties, examining the range of behavior across the sample, and characterizing the appearance of blazars in such a survey so that future work can more easily identify such objects. The survey, which covers 15,000 square degrees multiple times over 3.5 years, allows for the first ensemble blazar study of this scale. Variability amplitude distributions are shown for the FSRQ and BL Lac samples for numerous time lags, and also studied through structure function analyses. Individual blazars show a wide range of variability amplitudes, timescales, and duty cycles. Of the best sampled objects, 35% are seen to vary by more than 0.4 magnitudes; for these, the fraction of measurements contributing to the high amplitude variability ranges constantly from about 5% to 80%. Blazar variability has some similarities to that of type I quasars but includes larger amplitude fluctuations on all timescales. FSRQ variability amplitudes are particularly similar to those of QSOs on timescales of several months, suggesting significant contributions from the accretion disk to the variable flux at these timescales. Optical variability amplitudes are correlated with the maximum apparent velocities of the radio jet for the subset of FSRQs with MOJAVE VLBA measurements, implying that the optically variable flux's strength is typically related to that of the radio emission. We also study CRATES radio-selected FSRQ candidates, which show similar variability characteristics to known FSRQs; this suggests a high purity for the CRATES sample.Comment: 29 pages, 12 figures. Accepted for publication in Ap

    Understanding Factors Associated With Psychomotor Subtypes of Delirium in Older Inpatients With Dementia

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    Immunosuppression for older liver transplant recipients

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    Older liver transplant recipients have a lower risk of acute rejection than younger patients (9% for patients aged ≥65 years versus 23% for those aged 18–34 years) and are more vulnerable to immunosuppression-related complications. The number of liver transplant recipients ≥65 years has risen to 22% in Europe and the US, but limited information is available on the optimal immunosuppressive regimen for these patients. In this review, we discuss the appropriate management of immunosuppressive agents in older adults to minimize adverse events while avoiding acute rejection. The way the body processes drugs greatly depends on age. In the case of calcineurin inhibitor drugs, aging reduces hepatic metabolism, leading to changes in their pharmacokinetics. Corticosteroids also show decreased clearance as the patient ages. In severe cases of hypoalbuminemia, dose adjustment of mycophenolate acid derivatives may be necessary. However, the pharmacokinetic profiles of the mammalian target of rapamycin inhibitors, basiliximab, and rabbit anti-thymocyte globulin remain unaffected by age. Furthermore, age-related frailty may impact drug metabolism and require tailored interventions and closer follow-up. Although there is limited research, elderly liver transplant recipients require less immunosuppression with double or triple-agent regimens, lower exposure to calcineurin inhibitors, and a shorter course of corticosteroids. The usage of mammalian target of rapamycin inhibitors in older transplant populations has not been specifically investigated, and thus their usage should align with indications for younger patient groups

    Treatment of Supra-Alveolar-Type Defects by a Simplified Papilla Preservation Technique for Access Flap Surgery With or Without Enamel Matrix Proteins

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    Background: In this study, we compare the effectiveness of enamel matrix derivative (EMD) associated with a simplified papilla preservation flap (SPPF) technique to SPPF alone when surgically treating supra-alveolar-type defects. Methods: Fifty patients, from 54 initially selected, presenting horizontal bone loss around 4 adjacent teeth, were treated by an SPPF technique; 25 participants also received EMD (test group) and 25 patients underwent flap surgery alone (control group). A complete clinical and radiographic examination was performed at baseline and 12 months after treatment. Pre- and post-therapy probing depth (PD), clinical attachment level (CAL), gingival recession (GR), and radiographic bone level (BL) were compared between treatments. Results: After 12 months, PD, CAL, and GR in both groups showed significant differences from baseline (P <0.001). No differences in BL scores were observed within the groups at the 12-month examination. After 1 year, the test group showed significantly (P <0.001) greater PD reduction (3.4 +/- 0.7 mm) and CAL gain (2.8 +/- 0.8 mm) and a smaller GR increase (0.6 +/- 0.4 mm) compared to the control group (PD, 2.2 +/- 0.8 mm; CAL, 1.0 +/- 0.6 mm; GR, 1.2 +/- 0.7 mm.) BL changes did not significantly differ between the experimental groups. Conclusion: The results of this study suggest that combining EMD and SPPF in the treatment of suprabony defects may lead to a greater clinical improvement compared to SPPF alone
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