98 research outputs found
Reference Force Field and CDW Amplitude of Mixed-Valence Halogen-Bridged Pt Complexes
The spectroscopic effects of electron-phonon coupling in mixed-valence
chlorine-bridged Pt chains complexes are investigated through a parallel
infrared and Raman study of three compounds with decreasing Pt-Pt distance
along the chain. The e-ph interaction is analyzed in terms of the
Herzberg-Teller coupling scheme. We take into account the quadratic term and
define a precise reference state. The force field relevant to this state is
constructed, whereas the electronic structure is analyzed in terms of a simple
phenomenological model, singling out a trimeric unit along the chain. In this
way we are able to account for all the available optical data of the three
compounds, and to estimate the relevant microscopic parameters, such as the
e-ph coupling constants and the CDW amplitude.Comment: 10 pages, compressed postscript, 6 Tables and 5 Figures also in a
compressed ps.Z file. Revision is in the submission format only (postscript
instead of tex
Recurrence and mortality according to Estrogen Receptor status for breast cancer patients undergoing conservative surgery. Ipsilateral breast tumour recurrence dynamics provides clues for tumour biology within the residual breast
BACKGROUND: The study was designed to determine how tumour hormone receptor status affects the subsequent pattern over time (dynamics) of breast cancer recurrence and death following conservative primary breast cancer resection.
METHODS: Time span from primary resection until both first recurrence and death were considered among 2825 patients undergoing conservative surgery with or without breast radiotherapy. The hazard rates for ipsilateral breast tumour recurrence (IBTR), distant metastasis (DM) and mortality throughout 10 years of follow-up were assessed.
RESULTS: DM dynamics displays the same bimodal pattern (first early peak at about 24 months, second late peak at the sixth-seventh year) for both estrogen receptor (ER) positive (P) and negative (N) tumours and for all local treatments and metastatic sites. The hazard rates for IBTR maintain the bimodal pattern for ERP and ERN tumours; however, each IBTR recurrence peak for ERP tumours is delayed in comparison to the corresponding timing of recurrence peaks for ERN tumours. Mortality dynamics is markedly different for ERP and ERN tumours with more early deaths among patients with ERN than among patients with ERP primary tumours.
CONCLUSION: DM dynamics is not influenced by the extent of conservative primary tumour resection and is similar for both ER phenotypes across different metastatic sites, suggesting similar mechanisms for tumour development at distant sites despite apparently different microenvironments. The IBTR risk peak delay observed in ERP tumours is an exception to the common recurrence risk rhythm. This suggests that the microenvironment within the residual breast tissue may enforce more stringent constraints upon ERP breast tumour cell growth than other tissues, prolonging the latency of IBTR. This local environment is, however, apparently less constraining to ERN cells, as IBTR dynamics is similar to the corresponding recurrence dynamics among other distant tissue
Clinical features and outcomes of elderly hospitalised patients with chronic obstructive pulmonary disease, heart failure or both
Background and objective: Chronic obstructive pulmonary disease (COPD) and heart failure (HF) mutually increase the risk of being present in the same patient, especially if older. Whether or not this coexistence may be associated with a worse prognosis is debated. Therefore, employing data derived from the REPOSI register, we evaluated the clinical features and outcomes in a population of elderly patients admitted to internal medicine wards and having COPD, HF or COPD + HF. Methods: We measured socio-demographic and anthropometric characteristics, severity and prevalence of comorbidities, clinical and laboratory features during hospitalization, mood disorders, functional independence, drug prescriptions and discharge destination. The primary study outcome was the risk of death. Results: We considered 2,343 elderly hospitalized patients (median age 81 years), of whom 1,154 (49%) had COPD, 813 (35%) HF, and 376 (16%) COPD + HF. Patients with COPD + HF had different characteristics than those with COPD or HF, such as a higher prevalence of previous hospitalizations, comorbidities (especially chronic kidney disease), higher respiratory rate at admission and number of prescribed drugs. Patients with COPD + HF (hazard ratio HR 1.74, 95% confidence intervals CI 1.16–2.61) and patients with dementia (HR 1.75, 95% CI 1.06–2.90) had a higher risk of death at one year. The Kaplan–Meier curves showed a higher mortality risk in the group of patients with COPD + HF for all causes (p = 0.010), respiratory causes (p = 0.006), cardiovascular causes (p = 0.046) and respiratory plus cardiovascular causes (p = 0.009). Conclusion: In this real-life cohort of hospitalized elderly patients, the coexistence of COPD and HF significantly worsened prognosis at one year. This finding may help to better define the care needs of this population
Uma pesquisa-ação-intervenção em Saúde Bucal Coletiva: contribuindo para a produção de novas análises
Este artigo tem como objetivo apresentar a estratégia metodológica produzida e exercitada durante o desenvolvimento de uma pesquisa de doutorado que tomou como quadro teórico-metodológico a abordagem da Análise Institucional na Saúde Coletiva. Pretende, também, contribuir para o debate sobre as abordagens metodológicas que colocam em pauta a relação entre o pesquisador e o ato de pesquisar. Ao longo da investigação, a pesquisa-ação foi se configurando e se (entre)cruzando com a pesquisa-intervenção, num percurso que estamos denominando pesquisa-ação-intervenção. Desse modo, a pesquisadora, os momentos da pesquisa e da produção teórico-metodológica foram construídos/constituídos ao mesmo tempo, num processo mediatizado pelos saberes e pelos não-saberes dos sujeitos implicados com esta investigação. Podemos dizer que houve dois processos articulados de ação-intervenção: um da pesquisadora no e com o grupo, e, outro, dos participantes do grupo, profissionais do Sistema Único de Saúde do município de Campinas em seu cotidiano, na produção do cuidado em Saúde Bucal.This article describes the methodological strategy created during the research carried out for a doctoral degree, with Institutional Analysis in Collective Health being used as the theoretical and methodological framework. The article is thus meant as a contribution to the debate on methodological approaches to the relationships between researchers and their act of researching. During the investigation, action-research operated as a crossroad between intervention and research, along a path we refer to as intervention-research-action. The research stages and the theoretical-methodological production were constructed concurrently, in a process mediated by the knowledge and questions of the subjects related to this investigation. Knowledge production in the area of oral health care was made through two articulated processes of intervention-action: one of the researcher in and within the group, other of the participants in the group, namely professionals in public health in their everyday life work in oral health care
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