846 research outputs found

    Quantitative Investigations of Polygonal Patterned Ground in Continental Antarctica: A Mars analogue

    Get PDF
    Polygonal fractured ground is widespread at middle and high latitudes on Mars. The latitude-dependence and the morphologic similarity to terrestrial patterned ground in permafrost regions may indicate a formation as thermal contraction cracks, but the exact formation mechanisms are still unclear. This study quantitatively investigates polygonal networks in icefree parts of continental Antarctica to help distinguishing between different hypotheses of their origin on Mars

    EBV-associated post-transplantation B-cell lymphoproliferative disorder following allogenic stem cell transplantation for acute lymphoblastic leukaemia: tumor regression after reduction of immunosuppression - a case report

    Get PDF
    Epstein-Barr virus (EBV)-associated B-cell post-transplantation lymphoproliferative disorder (PTLD) is a severe complication following stem cell transplantation. This is believed to occur as a result of iatrogenic immunosuppression leading to a relaxation of T-cell control of EBV infection and thus allowing viral reactivation and proliferation of EBV-infected B-lymphocytes. In support of this notion, reduction of immunosuppressive therapy may lead to regression of PTLD

    Mixed hepatoblastoma and teratoma of the liver in a 3-year-old child: a unique combination and clinical challenge

    Get PDF
    Primary liver tumors in children are rare with malignant hepatoblastoma being the most common neoplasm. In this report, we describe the diagnosis and clinical management of a large liver tumor in a 3-year-old child that displayed the features of both, conventional hepatoblastoma and malignant teratoma. Pathological assessment on a pre-operative bioptical specimen showed an immature teratoid tumor with no area of hepatoblastic differentiation present. Histological and immunhistological examination of the resected tumor specimen additionally showed tumor areas of very different differentiation pattern intermixed with each other, namely areas of hepatoblastoma-typical and neuroblastoma-like morphology as well as areas of rhadomyosarcomatous differentiation

    Cardiac output measurement in children: comparison of the Ultrasound Cardiac Output Monitor with thermodilution cardiac output measurement

    Get PDF
    Objective: To compare the assessment of cardiac output (CO) in children using the noninvasive Ultrasound Cardiac Output Monitor (USCOM) with the invasive pulmonary artery catheter (PAC) thermodilution cardiac output measurement. Design and setting: Prospective observational study in atertiary center for pediatric cardiology of auniversity children's hospital. Patients: Twenty-four pediatric patients with congenital heart disease without shunt undergoing cardiac catheterization under general anesthesia. Measurements and results: CO was measured by USCOM using asuprasternal CO Doppler probe in children undergoing cardiac catheterization. USCOM data were compared to CO simultaneously measured by PAC thermodilution technique. Measurements were repeated three times within 5 min in each patient. Amean percentage error not exceeding 30% was defined as indicating clinical useful reliability of the USCOM. CO values measured by PAC ranged from 1.3 to 5.3 l/min (median 3.6 l/min). Bias and precision were −0.13 and 1.34 l/min, respectively. The mean percentage error of CO measurement by the USCOM compared to PAC thermodilution technique was 36.4% for USCOM. Conclusions: Our preliminary data demonstrate that cardiac output measurement in children using the USCOM does not reliably represent absolute CO values as compared to PAC thermodilution. Further studies must evaluate the impact of incorporating effective aortic valve diameters on CO measurement using the USCO

    A systematic review of home-based dietary interventions during radiation therapy for cancer.

    Get PDF
    Purpose: Our objectives are to assess (1) the acceptability and feasibility of dietary interventions for patients undergoing radiation therapy (RT), and (2) the impact of dietary interventions on patient reported outcomes, toxicities, and survival. Methods: A PICOS/PRISMA/MOOSE selection protocol was used to include articles that evaluate adding dietary interventions to patients receiving RT. Acceptability was defined as (# accepting/# approached); feasibility was (# completing/# approached). Patient-reported outcomes were reported based on questionnaires used in each study and survival was measured from the date of diagnosis until death in each study. Level of evidence was assessed with Center for Evidence-Based Medicine (CEBM) criteria. Results: Sixteen articles were included; among these, 2027 patients were approached regarding the intervention, and 1661 accepted (81.9%); of these, 1543 (92.9%) completed the prescribed diet + RT course. The most common cancers included were gynecological, head and neck, and gastrointestinal. For patients with pelvic cancers, a high fiber diet may improve diarrhea (CEBM level 1b). Enteral nutrition formula, including formulas with proteins such as L-arginine, lipids such as eicosapentaenoic acids, glucids, and ribonucleotides, may help prevent of malnutrition in head and neck cancer patients undergoing RT (level 2b). Vitamin C and β-carotene may reduce of xerostomia in head and neck cancer patients; however, the studies evaluating these vitamins included vitamin E, which increases all-cause mortality (level 2b). No dietary intervention for cancer patients receiving RT has been shown to improve survival. Conclusion: There are limited data to support safe and efficacious use of dietary interventions during RT

    The Role of Motivational Regulation in Exam Preparation: Results From a Standardized Diary Study

    Get PDF
    Previous studies have shown that the use of motivational regulation strategies has the potential to sustain invested effort and persistence in the learning process. Combining different methods (questionnaires and standardized diaries), the present study aimed to determine the role of motivational regulation in an exam preparation period. Motivational regulation is differentiated in a quantitative (extent of strategy use) and a qualitative (planning, implementing, monitoring, and correcting strategy use) aspect. One hundred and fifteen university students reported the quantity and quality of their motivational regulation strategy use in a pretest and kept a standardized learning diary focused on motivational difficulties and invested effort over a 14-day period just before an exam in their studies. Exam performance was assessed afterward. Results revealed positive effects of both aspects of motivational regulation on invested effort in exam preparation and exam performance. Moreover, a high quality of motivational regulation was associated with reduced negative effects of motivational difficulties on invested effort during studying—implying that motivational regulation can buffer against specific motivational problems occurring in the learning process
    corecore