45 research outputs found

    Eccentricities of Planets in Binary Systems

    Full text link
    The most puzzling property of the extrasolar planets discovered by recent radial velocity surveys is their high orbital eccentricities, which are very difficult to explain within our current theoretical paradigm for planet formation. Current data reveal that at least 25% of these planets, including some with particularly high eccentricities, are orbiting a component of a binary star system. The presence of a distant companion can cause significant secular perturbations in the orbit of a planet. At high relative inclinations, large-amplitude, periodic eccentricity perturbations can occur. These are known as "Kozai cycles" and their amplitude is purely dependent on the relative orbital inclination. Assuming that every planet host star also has a (possibly unseen, e.g., substellar) distant companion, with reasonable distributions of orbital parameters and masses, we determine the resulting eccentricity distribution of planets and compare it to observations? We find that perturbations from a binary companion always appear to produce an excess of planets with both very high (e>0.6) and very low (e<0.1) eccentricities. The paucity of near-circular orbits in the observed sample implies that at least one additional mechanism must be increasing eccentricities. On the other hand, the overproduction of very high eccentricities observed in our models could be combined with plausible circularization mechanisms (e.g., friction from residual gas) to create more planets with intermediate eccentricities (e=0.1-0.6).Comment: 8 pages, to appear in "Close Binaries in the 21st Century: New Opportunities and Challenges", ed. A. Gimenez et al. (Springer

    Patient perspectives on consequences of resection for colorectal cancer: a qualitative study

    Get PDF
    BackgroundColorectal cancer is diagnosed in approximately 500,000 patients each year in Europe, leading to a high number of patients having to cope with the consequences of resection for colorectal cancer. As treatment options tend to grow, more information on the effects of these treatments is needed to engage in shared decision-making. This study aims to explore the impact of resection for colorectal cancer on patients' daily life.MethodsPatients (≥18 years of age) who underwent an oncological colorectal resection between 2018 and 2021 were selected. Purposeful sampling was used to include patients who differed in age, comorbidity conditions, types of (neo)adjuvant therapy, postoperative complications and the presence/absence of a stoma. Semi-structured interviews were conducted, guided by a topic guide. Interviews were fully transcribed and subsequently thematically analysed using the framework approach. Analyses were carried out using the following predefined themes: (1) daily life and activities; (2) psychological functioning; (3) social functioning; (4) sexual functioning; and (5) healthcare experiences.ResultsSixteen patients with a follow-up period of between 0.6 and 4.4 years after surgery were included in this study. Participants reported several challenges experienced because of poor bowel function, a stoma, chemotherapy-induced neuropathy, fear of recurrence and sexual dysfunction. However, they reported these as not interfering much with daily life.ConclusionColorectal cancer treatment leads to several challenges and treatment-related health deficits. This is often not recognized by generic patient-reported outcome measures, but the findings on treatment-related health deficits presented in this study contain valuable insights which might contribute to improving colorectal cancer care, shared decision making and value-based health care.Surgical oncolog

    Association between glycated haemoglobin levels and cardiovascular outcomes in patients with type 2 diabetes and cardiovascular disease: a secondary analysis of the TECOS randomized clinical trial

    Get PDF
    Aims: Whether glycaemic control is associated with cardiovascular outcomes in patients with type 2 diabetes (T2D) is unclear. Consequently, we assessed the relationship between glycated haemoglobin (HbA1c) and cardiovascular outcomes in a placebo-controlled randomized trial which demonstrated no cardiovascular effect of sitagliptin in patients with T2D and atherosclerotic vascular disease. Methods and results: Secondary analysis of 14 656 TECOS participants with time to event analyses using multivariable Cox proportional hazard models. During a median 3.0 (interquartile range 2.3–3.8) year follow-up, 456 (3.1% of 14 656) patients had first hospitalization for heart failure (HF), 1084 (11.5%) died, 1406 (9.6%) died or were hospitalized for HF, and 1689 (11.5%) had a non-HF cardiovascular event (cardiovascular death, non-fatal stroke, non-fatal myocardial infarction, or hospitalization for unstable angina). Associations between baseline or time-varying HbA1c and cardiovascular outcomes were U-shaped, with the lowest risk when HbA1c was around 7%. Each one-unit increase in the time-varying HbA1c above 7% was associated with an adjusted hazard ratio (HR) of 1.21 [95% confidence interval (CI) 1.11–1.33] for first HF hospitalization, 1.11 (1.03–1.21) for all-cause death, 1.18 (1.09–1.26) for death or HF hospitalization, and 1.10 (1.02–1.17) for non-HF cardiovascular events. Each one-unit decrease in the time-varying HbA1c below 7% was associated with an adjusted HR of 1.35 (95% CI 1.12–1.64) for first HF hospitalization, 1.37 (1.16–1.61) for death, 1.42 (1.23–1.64) for death or HF hospitalization, and 1.22 (1.06–1.41) for non-HF cardiovascular events. Conclusion: Glycated haemogobin exhibits a U-shaped association with cardiovascular outcomes in patients with T2D and atherosclerotic vascular disease, with nadir around 7%. Clinical Trial Registration: ClinicalTrials.gov Identifier: NCT00790205

    Nitric oxide sensing in plants is mediated by proteolytic control of group VII ERF transcription factors

    Get PDF
    Nitric oxide (NO) is an important signaling compound in prokaryotes and eukaryotes. In plants, NO regulates critical developmental transitions and stress responses. Here, we identify a mechanism for NO sensing that coordinates responses throughout development based on targeted degradation of plant-specific transcriptional regulators, the group VII ethylene response factors (ERFs). We show that the N-end rule pathway of targeted proteolysis targets these proteins for destruction in the presence of NO, and we establish them as critical regulators of diverse NO-regulated processes, including seed germination, stomatal closure, and hypocotyl elongation. Furthermore, we define the molecular mechanism for NO control of germination and crosstalk with abscisic acid (ABA) signaling through ERF-regulated expression of ABSCISIC ACID INSENSITIVE5 (ABI5). Our work demonstrates how NO sensing is integrated across multiple physiological processes by direct modulation of transcription factor stability and identifies group VII ERFs as central hubs for the perception of gaseous signals in plants

    Consequences of CT colonography in stenosing colorectal cancer

    Get PDF
    Imaging- and therapeutic targets in neoplastic and musculoskeletal inflammatory diseas

    Induction chemotherapy followed by chemoradiotherapy versus chemoradiotherapy alone as neoadjuvant treatment for locally recurrent rectal cancer: study protocol of a multicentre, open-label, parallel-arms, randomized controlled study (PelvEx II)

    Get PDF
    Background: A resection with clear margins (R0 resection) is the most important prognostic factor in patients with locally recurrent rectal cancer (LRRC). However, this is achieved in only 60 per cent of patients. The aim of this study is to investigate whether the addition of induction chemotherapy to neoadjuvant chemo(re)irradiation improves the R0 resection rate in LRRC. Methods: This multicentre, international, open-label, phase III, parallel-arms study will enrol 364 patients with resectable LRRC after previous partial or total mesorectal resection without synchronous distant metastases or recent chemo- and/or radiotherapy treatment. Patients will be randomized to receive either induction chemotherapy (three 3-week cycles of CAPOX (capecitabine, oxaliplatin), four 2-week cycles of FOLFOX (5-fluorouracil, leucovorin, oxaliplatin) or FOLFORI (5-fluorouracil, leucovorin, irinotecan)) followed by neoadjuvant chemoradiotherapy and surgery (experimental arm) or neoadjuvant chemoradiotherapy and surgery alone (control arm). Tumours will be restaged using MRI and, in the experimental arm, a further cycle of CAPOX or two cycles of FOLFOX/FOLFIRI will be administered before chemoradiotherapy in case of stable or responsive disease. The radiotherapy dose will be 25 × 2.0 Gy or 28 × 1.8 Gy in radiotherapy-naive patients, and 15 × 2.0 Gy in previously irradiated patients. The concomitant chemotherapy agent will be capecitabine administered twice daily at a dose of 825 mg/m2 on radiotherapy days. The primary endpoint of the study is the R0 resection rate. Secondary endpoints are long-term oncological outcomes, radiological and pathological response, toxicity, postoperative complications, costs, and quality of life. Discussion: This trial protocol describes the PelvEx II study. PelvEx II, designed as a multicentre, open-label, phase III, parallel-arms study, is the first randomized study to compare induction chemotherapy followed by neoadjuvant chemo(re)irradiation and surgery with neoadjuvant chemo(re)irradiation and surgery alone in patients with locally recurrent rectal cancer, with the aim of improving the number of R0 resections.E. L. K. Voogt ... H. M. Kroon ... T. Sammour ... et al. (PelvEx Collaborative

    Vaginal and perineal reconstruction using rectus abdominis myocutaneous flap in surgery for locally advanced rectum carcinoma and locally recurrent rectum carcinoma:Dynamic article

    No full text
    Background: Surgery for locally advanced and recurrent rectal carcinoma sometimes requires partial resection of the perineum and/or vagina necessitating subsequent reconstruction. Objective: The aim of this study was to describe the surgical and functional outcomes of reconstructing the vagina and/or the perineum by using the vertical rectus abdominis myocutaneous flap and to evaluate the health status of patients who received reconstruction. Desgn: This is a retrospective cohort study. Settings: This study was conducted at a tertiary referral hospital for locally advanced and recurrent rectal cancer. Patients: Patients receiving multimodality treatment for primary or recurrent locally advanced rectal carcinomas were included. Main outcome measures: First, the surgical outcome was assessed. Second, 10 female patients who received vaginal reconstruction underwent a gynecological examination including biopsies. Finally, quality of life was assessed and compared with patients who underwent treatment for rectal carcinoma without a reconstruction. Results: Fifty-one patients underwent reconstruction of the dorsal vagina and/or the perineum with the use of a vertical rectus abdominis myocutaneous flap. In 13 patients, the flap was used to close a perineal defect; in 26 patients, to close a vaginal defect; and in 12 patients, to close both. In 3 patients, partial necrosis of the flap occurred that was treated conservatively. In 4 patients, stenosis of the introitus occurred, as found in the gynecological examination. Biopsies confirmed epithelialization of the vaginal wall. All groups reported good functioning and low symptom burden. After vaginal reconstruction, women reported equal or higher scores on global health status, emotional functioning, and body image. Limitations: The lack of information on the health status of the patients before the start of treatment prohibits making causal inferences in health status over time. Discussion: Reconstruction of the perineum and/or dorsal vagina was successful in all patients. Surgeons and gynecologists who use the vertical rectus abdominis myocutaneous flap should be aware of stenosis of the vaginal introitus. Gynecological consultation at an early stage should be standard
    corecore