186 research outputs found

    Quantum friction

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    The Brownian motion of a light quantum particle in a heavy classical gas is theoretically described and a new expression for the friction coefficient is obtained for arbitrary temperature. At zero temperature it equals to the de Broglie momentum of the mean free path divided by the mean free path. Alternatively, the corresponding mobility of the quantum particle in the classical gas is equal to the square of the mean free path divided by the Planck constant. The Brownian motion of a quantum particle in a quantum environment is also discussed.Comment: The paper is dedicated to the 85th anniversary of N.N. Tyutyulko

    Clinical management of women with metastatic breast cancer: a descriptive study according to age group

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    BACKGROUND: The primary aim of treatment of a patient who has developed metastatic disease is palliation. The objectives of the current study are to describe and quantify the clinical management of women with metastatic breast cancer from the diagnosis of metastatic disease until death and to analyze differences between age groups. METHODS: Data were collected from the medical files of all patients (n = 116) who had died after December 31, 1999, after a diagnosis of metastatic breast cancer in two teaching hospitals in the south of the Netherlands. RESULTS: Of the 116 patients included in our study, 10 (9%) already had metastatic disease at diagnosis and 106 developed distant disease after the diagnosis of localized breast cancer. Before they died, 70% of the 116 patients developed metastases in one or more bones, 50% in the lung and/or pleura, 50% in the abdominal viscera, 23% in the central nervous system, and 19% in the skin. Patients younger than 50 years were much more likely to develop metastases in the central nervous system than patients 50 years and older. Seventy-seven (66%) of the 116 patients with metastatic breast cancer received chemotherapy. This proportion decreased with age (p = 0.005), as did the number of schemes per patient. Together, they received 132 chemotherapy schemes, of which 35 (27%) resulted in partial remission or stabilization of the disease process. Ninety-eight patients (84%) received hormonal treatment. This proportion did not differ between the three age groups. Together, they received 216 hormonal treatments, 38 (16%) of which resulted in partial remission or stabilization of the disease process. Seventy-nine patients (68%) received palliative radiotherapy. This proportion decreased with age (p = 0.03). Together, they underwent 216 courses, 176 (77%) of which resulted in relief of the complaints. CONCLUSION: Patients aged 70 years and older are less likely to receive chemotherapy or radiotherapy. Part of this difference could be explained by their shorter survival time after the diagnosis of metastatic disease and their lower risk of developing brain and bone metastases. However, more research is needed to understand the age-related differences in the treatment of metastatic breast cancer, and especially how comorbidity and frailty limit therapeutic choices

    Brownian markets

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    Financial market dynamics is rigorously studied via the exact generalized Langevin equation. Assuming market Brownian self-similarity, the market return rate memory and autocorrelation functions are derived, which exhibit an oscillatory-decaying behavior with a long-time tail, similar to empirical observations. Individual stocks are also described via the generalized Langevin equation. They are classified by their relation to the market memory as heavy, neutral and light stocks, possessing different kinds of autocorrelation functions

    Towards a better future for Canadians with bipolar disorder:principles and implementation of a community-based participatory research model

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    The Collaborative RESearch Team to study psychosocial factors in bipolar disorder (CREST.BD) is a multidisciplinary network dedicated to advancing science and practice around psychosocial issues associated with bipolar disorder (BD), improving the care and wellness of people living with bipolar disorder, and strengthening services and supports for these individuals. CREST.BD specializes in community-based participatory research, in which research is conducted as a partnership between researchers and community members. This article describes the evolution of the CREST.BD network and CREST.BD’s commitment to community-based participatory research in bipolar disorder research. Examples of CREST.BD projects using community-based participatory research to study stigma, quality of life, psychosocial interventions, and creativity in bipolar disorder are highlighted, and opportunities and challenges of engaging in community-based participatory research in bipolar disorder specifically and the mental health field more broadly are discussed. This article demonstrates how CBPR can be used to enhance the relevance of research practices and products through community engagement, and how community-based participatory research can enrich knowledge exchange and mobilization

    Planned Cesarean or planned vaginal delivery for twins : secondary analysis of randomized controlled trial

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    ACKNOWLEDGMENTS We thank all the participants in the Twin Birth Study and the staff at the Centre for Mother, Infant, and Child Research for their hard work and dedication. The Twin Birth Study was supported by a grant (63164) from the Canadian Institute of Health Research. P.T. and M.H.Z. were supported by a grant from The Netherlands Organization for Scientific Research (NWO ‐ grant number 401.16.080). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Peer reviewedPublisher PD

    Canadian Network for Mood and Anxiety Treatments (CANMAT) and International Society for Bipolar Disorders (ISBD) 2018 guidelines for the management of patients with bipolar disorder

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    The Canadian Network for Mood and Anxiety Treatments (CANMAT) previously published treatment guidelines for bipolar disorder in 2005, along with international commentaries and subsequent updates in 2007, 2009, and 2013. The last two updates were published in collaboration with the International Society for Bipolar Disorders (ISBD). These 2018 CANMAT and ISBD Bipolar Treatment Guidelines represent the significant advances in the field since the last full edition was published in 2005, including updates to diagnosis and management as well as new research into pharmacological and psychological treatments. These advances have been translated into clear and easy to use recommendations for first, second, and third- line treatments, with consideration given to levels of evidence for efficacy, clinical support based on experience, and consensus ratings of safety, tolerability, and treatment-emergent switch risk. New to these guidelines, hierarchical rankings were created for first and second- line treatments recommended for acute mania, acute depression, and maintenance treatment in bipolar I disorder. Created by considering the impact of each treatment across all phases of illness, this hierarchy will further assist clinicians in making evidence-based treatment decisions. Lithium, quetiapine, divalproex, asenapine, aripiprazole, paliperidone, risperidone, and cariprazine alone or in combination are recommended as first-line treatments for acute mania. First-line options for bipolar I depression include quetiapine, lurasidone plus lithium or divalproex, lithium, lamotrigine, lurasidone, or adjunctive lamotrigine. While medications that have been shown to be effective for the acute phase should generally be continued for the maintenance phase in bipolar I disorder, there are some exceptions (such as with antidepressants); and available data suggest that lithium, quetiapine, divalproex, lamotrigine, asenapine, and aripiprazole monotherapy or combination treatments should be considered first-line for those initiating or switching treatment during the maintenance phase. In addition to addressing issues in bipolar I disorder, these guidelines also provide an overview of, and recommendations for, clinical management of bipolar II disorder, as well as advice on specific populations, such as women at various stages of the reproductive cycle, children and adolescents, and older adults. There are also discussions on the impact of specific psychiatric and medical comorbidities such as substance use, anxiety, and metabolic disorders. Finally, an overview of issues related to safety and monitoring is provided. The CANMAT and ISBD groups hope that these guidelines become a valuable tool for practitioners across the globe

    Canadian Network for Mood and Anxiety Treatments (CANMAT) and International Society for Bipolar Disorders (ISBD) collaborative update of CANMAT guidelines for the management of patients with bipolar disorder: Update 2013

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    The Canadian Network for Mood and Anxiety Treatments published guidelines for the management of bipolar disorder in 2005, with updates in 2007 and 2009. This third update, in conjunction with the International Society for Bipolar Disorders, reviews new evidence and is designed to be used in conjunction with the previous publications.The recommendations for the management of acute mania remain largely unchanged. Lithium, valproate, and several atypical antipsychotic agents continue to be first-line treatments for acute mania. Monotherapy with asenapine, paliperidone extended release (ER), and divalproex ER, as well as adjunctive asenapine, have been added as first-line options.For the management of bipolar depression, lithium, lamotrigine, and quetiapine monotherapy, as well as olanzapine plus selective serotonin reuptake inhibitor (SSRI), and lithium or divalproex plus SSRI/bupropion remain first-line options. Lurasidone monotherapy and the combination of lurasidone or lamotrigine plus lithium or divalproex have been added as a second-line options. Ziprasidone alone or as adjunctive therapy, and adjunctive levetiracetam have been added as not-recommended options for the treatment of bipolar depression. Lithium, lamotrigine, valproate, olanzapine, quetiapine, aripiprazole, risperidone long-acting injection, and adjunctive ziprasidone continue to be first-line options for maintenance treatment of bipolar disorder. Asenapine alone or as adjunctive therapy have been added as third-line options. © 2012 John Wiley and Sons A/S

    Common Data Elements to Facilitate Sharing and Re-use of Participant-Level Data: Assessment of Psychiatric Comorbidity Across Brain Disorders

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    The Ontario Brain Institute\u27s “Brain-CODE” is a large-scale informatics platform designed to support the collection, storage and integration of diverse types of data across several brain disorders as a means to understand underlying causes of brain dysfunction and developing novel approaches to treatment. By providing access to aggregated datasets on participants with and without different brain disorders, Brain-CODE will facilitate analyses both within and across diseases and cover multiple brain disorders and a wide array of data, including clinical, neuroimaging, and molecular. To help achieve these goals, consensus methodology was used to identify a set of core demographic and clinical variables that should be routinely collected across all participating programs. Establishment of Common Data Elements within Brain-CODE is critical to enable a high degree of consistency in data collection across studies and thus optimize the ability of investigators to analyze pooled participant-level data within and across brain disorders. Results are also presented using selected common data elements pooled across three studies to better understand psychiatric comorbidity in neurological disease (Alzheimer\u27s disease/amnesic mild cognitive impairment, amyotrophic lateral sclerosis, cerebrovascular disease, frontotemporal dementia, and Parkinson\u27s disease)
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