1,772 research outputs found

    Single Fetal Death in Twin Pregnancy. What Will Be the Problems to the Surviving Co-Sib?

    Get PDF
    Na gravidez bigemelar, a morte de um dos fetos no segundo e terceiro trimestre é uma complicação rara, variando a taxa de incidência entre 2,6 e 6,8%. Este acontecimento determina um aumento das taxas de morbilidade e mortalidade perinatal para o gémeo sobrevivente, especialmente em gravidezes monocoriónicas, quando a morte fetal é devida à síndroma de tranfusão feto-fetal. Para alguns autores o atraso de crescimento intrauterino e a prematuridade são os principais factores de risco para o aumento da morbilidade e mortalidade do gémeo sobrevivente. A patofisiologia de instalação dos distúrbios cerebrais no gémeo sobrevivente após a morte do feto irmão não está definida, nem o intervalo de tempo que medeia entre a morte e o estabelecimento das lesões. Também não existe um protocolo definitivo de seguimento destas gravidezes e, posteriormente, do gémeo sobrevivente. No período de 1 de Setembro de 1994 a 31 de Dezembro de 1998, foram seguidas, na consulta de Gravidez Múltipla da Maternidade Dr. Alfredo da Costa, 235 gravidezes bigemelares. Em nove casos (3,8%) ocorreu morte de um dos fetos com idade gestacional acima das 13 semanas. Em cinco das nove gravidezes foi conhecida a causa de morte, quatro das quais foram atribuídas à síndroma de tranfusão feto-fetal. A taxa de prematuridade do gémeo sobrevivente foi de 44,4% (4/9) e a de mortalidade de 11,1%(1/9). A taxa de morbilidade neonatal foi de 62,5% (5/8), na maioria dos casos por complicações inerentes à prematuridade. A taxa de morbilidade neurológica foi de 37,5% (3/8). A taxa de lesões neurológicas major foi de 25% (2/8) e ocorreu em recém-nascidos de termo. A síndroma de transfusão feto-fetal, como causa de morte fetal, associou-se aos casos com pior prognóstico no que se referiu ao gémeo sobrevivente.O crescimento do gémeo sobrevivente parece depender das lesões provocadas pela morte do feto irmão. Os autores finalizam com uma proposta de atitudes obstétricas e pediátricas em relação ao gémeo sobrevivente

    Development of a dynamic framework to explain population patterns of leisure-time physical activity through agent-based modeling.

    Get PDF
    Despite the increasing body of evidences on the factors influencing leisure-time physical activity, our understanding of the mechanisms and interactions that lead to the formation and evolution of population patterns is still limited. Moreover, most frameworks in this field fail to capture dynamic processes. Our aim was to create a dynamic conceptual model depicting the interaction between key psychological attributes of individuals and main aspects of the built and social environments in which they live. This conceptual model will inform and support the development of an agent-based model aimed to explore how population patterns of LTPA in adults may emerge from the dynamic interplay between psychological traits and built and social environments. We integrated existing theories and models as well as available empirical data (both from literature reviews), and expert opinions (based on a systematic expert assessment of an intermediary version of the model). The model explicitly presents intention as the proximal determinant of leisure-time physical activity, a relationship dynamically moderated by the built environment (access, quality, and available activities) - with the strength of the moderation varying as a function of the person's intention- and influenced both by the social environment (proximal network's and community's behavior) and the person's behavior. Our conceptual model is well supported by evidence and experts' opinions and will inform the design of our agent-based model, as well as data collection and analysis of future investigations on population patterns of leisure-time physical activity among adults

    Toward Interdisciplinary Synergies in Molecular Communications: Perspectives from Synthetic Biology, Nanotechnology, Communications Engineering and Philosophy of Science

    Get PDF
    Within many chemical and biological systems, both synthetic and natural, communication via chemical messengers is widely viewed as a key feature. Often known as molecular communication, such communication has been a concern in the fields of synthetic biologists, nanotechnologists, communications engineers, and philosophers of science. However, interactions between these fields are currently limited. Nevertheless, the fact that the same basic phenomenon is studied by all of these fields raises the question of whether there are unexploited interdisciplinary synergies. In this paper, we summarize the perspectives of each field on molecular communications, highlight potential synergies, discuss ongoing challenges to exploit these synergies, and present future perspectives for interdisciplinary efforts in this area

    Utility of Prophylactic Percutaneous Gastrostomy in Patients With Head and Neck Cancer Receiving Concurrent Chemoradiotherapy: A Multicenter Analysis

    Get PDF
    Introduction: Patients with head and neck cancer (HNC) have an elevated incidence of cachexia and malnutrition due to the tumor's location interfering with oral feeding. Concurrent chemoradiation (CCRT) can have an emetic effect and cause dysphagia and oral mucositis. Adequate nutrition improves immunity, raises the response to therapy, reduces adverse effects, and improves survival. Numerous studies have suggested the utility of nutritional support from percutaneous endoscopic gastrostomy (PEG) in HNC patients. Although PEG is usually considered a safe procedure, it has a mortality rate of 0-2.2% and a risk of other procedure-related complications of 17-40%. Our work intends to evaluate the utility of PEG in patients with locally advanced HNC who underwent CCRT. Methods: We performed a cohort study at three institutions. We included patients with HNC who underwent definitive CCRT treatment from January 2013 to December 2022. The study consisted of an observational, descriptive, retrospective analysis of prespecified clinical data. Descriptive statistics were used to compare the data between the PEG group and the non-PEG group. Analysis of covariance (ANCOVA) was used for covariance analysis. Fisher's exact test was used to compare proportional data and Student's t-test was used to assess the differences in continuous data. Survival analysis was performed using the Kaplan-Meier estimator. P-values of <0.05 were considered to be indicative of statistical significance. The SPSS Statistics version 28.0 (Armonk, NY: IBM Corp.) was used to perform all statistical evaluations. Results: We identified 90 eligible patients diagnosed with local advanced HNC who had received definitive CCRT with three weekly cycles of cisplatin as follows: 44 with a prophylactic PEG tube and 46 without a prophylactic PEG tube. Most patients were male (84.4%) and 50% of patients were diagnosed with stage IVa HNC at the time of diagnosis. There wasn't an effect of PEG placement on BMI at the end of CCRT after controlling for the effect of baseline BMI (F {1.84}=0.065 {p=0.799}). In the study population, BMI was significantly lower after CCRT (21.30 kg/m2 vs. 23.97 kg/m2), t (86)=12.389, p<0.001. In the subgroup with baseline BMI <18.5 kg/m2 (15 patients), 90% of patients with prophylactic PEG were able to complete the three planned cycles of chemotherapy vs. 66.7% in the non-PEG group. Ten patients in the PEG group (22.7%) referred feeding tube dependency. Patients with dysphagia were 3.2 times more likely to have placed prophylactic PEG (p=0.007). The difference in overall survival and progression-free survival between the two groups was not statistically significant (p=0.57 and p=0.497, respectively). Conclusion: In this study using real-world data, we found a potentially protective effect of PEG in underweight patients with locally advanced HNC performing CCRT in order to complete three cycles of treatment.info:eu-repo/semantics/publishedVersio

    Imaging Coulomb Islands in a Quantum Hall Interferometer

    Full text link
    In the Quantum Hall regime, near integer filling factors, electrons should only be transmitted through spatially-separated edge states. However, in mesoscopic systems, electronic transmission turns out to be more complex, giving rise to a large spectrum of magnetoresistance oscillations. To explain these observations, recent models put forward that, as edge states come close to each other, electrons can hop between counterpropagating edge channels, or tunnel through Coulomb islands. Here, we use scanning gate microscopy to demonstrate the presence of quantum Hall Coulomb islands, and reveal the spatial structure of transport inside a quantum Hall interferometer. Electron islands locations are found by modulating the tunneling between edge states and confined electron orbits. Tuning the magnetic field, we unveil a continuous evolution of active electron islands. This allows to decrypt the complexity of high magnetic field magnetoresistance oscillations, and opens the way to further local scale manipulations of quantum Hall localized states

    Microbiological, histological, immunological, and toxin response to antibiotic treatment in the mouse model of Mycobacterium ulcerans disease.

    Get PDF
    Mycobacterium ulcerans infection causes a neglected tropical disease known as Buruli ulcer that is now found in poor rural areas of West Africa in numbers that sometimes exceed those reported for another significant mycobacterial disease, leprosy, caused by M. leprae. Unique among mycobacterial diseases, M. ulcerans produces a plasmid-encoded toxin called mycolactone (ML), which is the principal virulence factor and destroys fat cells in subcutaneous tissue. Disease is typically first manifested by the appearance of a nodule that eventually ulcerates and the lesions may continue to spread over limbs or occasionally the trunk. The current standard treatment is 8 weeks of daily rifampin and injections of streptomycin (RS). The treatment kills bacilli and wounds gradually heal. Whether RS treatment actually stops mycolactone production before killing bacilli has been suggested by histopathological analyses of patient lesions. Using a mouse footpad model of M. ulcerans infection where the time of infection and development of lesions can be followed in a controlled manner before and after antibiotic treatment, we have evaluated the progress of infection by assessing bacterial numbers, mycolactone production, the immune response, and lesion histopathology at regular intervals after infection and after antibiotic therapy. We found that RS treatment rapidly reduced gross lesions, bacterial numbers, and ML production as assessed by cytotoxicity assays and mass spectrometric analysis. Histopathological analysis revealed that RS treatment maintained the association of the bacilli with (or within) host cells where they were destroyed whereas lack of treatment resulted in extracellular infection, destruction of host cells, and ultimately lesion ulceration. We propose that RS treatment promotes healing in the host by blocking mycolactone production, which favors the survival of host cells, and by killing M. ulcerans bacilli

    REALMS Study: Real-World Effectiveness and Safety of Fingolimod in Patients with Relapsing-Remitting Multiple Sclerosis in Portugal

    Get PDF
    Background: Fingolimod, an oral sphingosine 1-phosphate receptor modulator, is approved by EMA for relapsing-remitting multiple sclerosis (RRMS). Objectives: To assess the effectiveness and safety of fingolimod in patients with RRMS in real-world clinical practice in Portugal. Methods: Retrospective, multicentre, non-interventional study, reporting 3 years follow-up of data collected from October 2015 to July 2016. Sociodemographic data and previous treatments at baseline and data regarding disease evolution, including number of relapses, annualised relapse rates (ARR) and Expanded Disability Status Scale (EDSS), were collected. Results: Two-hundred and seventy-five participants were enrolled in the REALMS study. Results showed that the main reason to switch to fingolimod was failure of previous treatment (56.7%) and only 3.6% were naïve patients. In the total population, there was a significant decrease in ARR of 64.6% in the first year of treatment, 79.7% in the second year and 82.3% in the third year, compared with baseline. More than 67.0% of patients had no relapses during the 3 years after switching to fingolimod. EDSS remained stable throughout the study. Conclusions: Therapy with fingolimod showed a sustained effectiveness and safety over the 3 years, particularly on patients switched from first-line drugs (BRACE). No new safety issues were reported.info:eu-repo/semantics/publishedVersio

    Modelling of the pH effect on the biosorption of heavy metals by marine algae Sargassum filipendula

    Get PDF
    Modelling of the pH effect on the biosorption of heavy metals by marine algae Sargassum filipendula. In this paper the biosorption of metal ions Cu(2+), Cd(2+) and Zn(2+) in single-component system by Sargassum filipendula pre-treated with 0.5 M CaCl(2) was studied. The experiments were carried out in a batch reactor at different fixed pH (3.0, 4.0, 5.0 and 6.0) and 30 degrees C. All the equilibrium data obtained were described using two pH-dependent isotherm models, based on the Langmuir isotherm. Artificial neural networks was also used to represent the pH effect on the biosorption equilibrium. The input of the networks were the equilibrium concentration of the metal in the fluid phase and the pH. As output the concentration of the metallic specie in the biosorbent was used. The results showed that the modeling using artificial neural networks technique represented the equilibrium data much better than the conventional modeling by the pH-dependent isotherm models.33443944
    • …
    corecore