532 research outputs found

    HEMATOSALPINX TORSION IN AN ADOLESCENT

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    Introdução: A torção da trompa de Falópio é uma causa rara de dor abdominal aguda. A gravidez ectópica, hidro ou hematossalpinge, endometriose, tumefações anexiais e outras causas de patologia anexial são fatores predisponentes. O diagnóstico é difícil de estabelecer, uma vez que os sinais clínicos, laboratoriais e imagiológicos são pouco específicos. O diagnóstico definitivo requer uma abordagem cirúrgica. Caso clínico: Os autores apresentam um caso de hematossalpinge e torção da mesma numa adolescente virgem sem fatores de risco conhecidos. Discussão: O caso evidencia a importância da reflexão sobre causas de hematossalpinge e recorda esta patologia como diagnóstico diferencial.Introduction: Isolated fallopian tube torsion is an uncommon cause of acute lower abdominal pain. Ectopic pregnancy, hydro or hematosalpinx, endometriosis, adnexal masses and other causes of adnexal disease are predisposing factors. The diagnosis is difficult and often delayed due to the lack of pathognomonic symptoms, characteristic physical signs, and specific imaging and laboratory studies. Definitive diagnosis requires a surgical approach. Case report: The authors present a case of hematosalpinx and its tubal torsion in a virgin teenager with no prior predisposing factors. Discussion: This rare case may highlight a new insight into pathophysiology of tubal torsion and recalls hematosalpinx as a differential diagnosi

    Longitudinal Spin Seebeck Effect thermopiles based on flexible Co-rich amorphous ribbons/Pt thin-film heterostructures

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    Thermoelectric phenomena, such as the Anomalous Nernst and Longitudinal Spin Seebeck Effects, are promising for sensor applications in the area of renewable energy. In the case of flexible electronic materials, the request is even larger because they can be integrated into devices having complex shape surfaces. Here, we reveal that Pt promotes an enhancement of the thermoelectric response in Co-rich ribbon/Pt heterostructures due to the spin-to-charge conversion. Moreover, we demonstrated that the employment of the thermopiles configuration in this system increases the induced thermoelectric current, a fact related to the considerable decrease in the electric resistance of the system. By comparing present findings with the literature, we were able to design a flexible thermopile based on LSSE without the lithography process. Additionally, the thermoelectric voltage found in the studied flexible heterostructures is comparable to the ones verified for rigid systems.This research was funded by different sources. M.A.C. thanks CAPES (8887.573100/2020-00) and CNPq. A.F. thanks the FCT (CTTI-31/18-C.F. (2) junior researcher contract). A.V.S. and G.V.K. were supported in the frame of the Priority-2030 Program of Ural Federal University

    Anomalous Nernst Effect in flexible co-based amorphous ribbons

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    Fe3Co67Cr3Si15B12 ribbons with a high degree of flexibility and excellent corrosion stability were produced by rapid quenching technique. Their structural, magnetic, and thermomagnetic (Anomalous Nernst Effect) properties were studied both in an as-quenched (NR) state and after stress annealing during 1 h at the temperature of 350 °C and a specific load of 230 MPa (AR). X-ray diffraction was used to verify the structural characteristics of our ribbons. Static magnetic properties were explored by inductive technique and vibrating sample magnetometry. The thermomagnetic curves investigated through the Anomalous Nernst Effect are consistent with the obtained magnetization results, presenting a linear response in the thermomagnetic signal, an interesting feature for sensor applications. Additionally, Anomalous Nernst Effect coefficient SANE values of 2.66μV/K and 1.93μV/K were estimated for the as-quenched and annealed ribbons, respectively. The interplay of the low magnetostrictive properties, soft magnetic behavior, linearity of the thermomagnetic response, and flexibility of these ribbons place them as promising systems to probe curved surfaces and propose multifunctional devices, including magnetic field-specialized sensors.M.A.C. thanks CAPES (8887.573100/2020-00) and CNPq. A.F. thanks the FCT (CTTI-31/18- C.F. (2) junior researcher contract). G.V.K was supported in the frame of the Priority-2030 Program of Ural Federal University

    Myocardial Work Brings New Insights into Left Ventricular Remodelling in Cardio-Oncology Patients

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    Serial transthoracic echocardiographic (TTE) assessment of 2D left ventricular ejection fraction (LVEF) and global longitudinal strain (GLS) are the gold standard screening methods for cancer therapeutics-related cardiac dysfunction (CTRCD). Non-invasive left ventricular (LV) pressure-strain loop (PSL) provides a novel method of quantifying myocardial work (MW) with potential advantages to evaluate the impact of cardiotoxic treatments on heart function. We prospectively assessed breast cancer female patients undergoing cancer therapy through serial monitoring by 2D and 3D TTE. Patients were evaluated at T0, T1 and T2 (before, 4-6 and 12-14 months after starting therapy, respectively). Through PSL analysis, MW indices were calculated. A total of 122 patients, with a mean age of 54.7 years, who received treatment with anthracyclines (77.0%) and anti-HER2 (75.4%) were included. During a mean follow-up of 14.9 ± 9.3 months, LVEF and GLS were significantly diminished, and 29.5% developed CTRCD. All MW indices were significantly reduced at T1 compared with baseline and tended to return to baseline values at T2. Global work index and global work efficiency showed a more pronounced variation in patients with CTRCD. The presence of more than one cardiovascular risk factor, obesity and baseline left atrium volume were predictors of changes in MW parameters. In conclusion, breast cancer treatment was associated with LV systolic dysfunction as assessed by MW, with its peak at 4-6 months and a partial recovery afterwards. Assessment of myocardial deformation parameters allows a more detailed characterization of cardiac remodelling and could enhance patient screening and selection for cardioprotective therapeutics.info:eu-repo/semantics/publishedVersio

    A Multicenter, Non-Interventional Study to Evaluate the Disease Activity in Multiple Sclerosis after Withdrawal of Natalizumab in Portugal

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    Objectives: Natalizumab (NTZ) is very effective for treatment of relapsing-remitting multiple sclerosis (RRMS), its use is mainly limited by safety issues. Discontinuation of NTZ is associated with recurrence of disease activity (reactivation and rebound). The best strategy for subsequent therapy and the predictive factors for recurrence in such patients are areas of active research. We aimed to evaluate predictors of reactivation in a multicentric study. Patients and methods: Multicentric retrospective observational study in five portuguese MS referral centers. Demographic, clinical and imagiological data were collected in the year prior, during and in the year following NTZ discontinuation. Predictors of reactivation and rebound after NTZ suspension were studied using a multivariate Cox model. Results: Sixty-nine patients were included. They were mainly non-naïve patients (97%), with a mean age of 29.1 ± 8.3 years at diagnosis, and a mean age of 37.2 ± 10.3 years at NTZ initiation. The mean annualized relapse rate (ARR) previous, during and after NTZ was 1.6 ± 1.2, 0.2 ± 0.5 and 0.6 ± 1.0, respectively. The median EDSS before, during and after NTZ was 3.5 (IQR 3.3), 3.5 (IQR 3.5) and 4.0 (IQR 3.8), respectively. The median number of infusions was 26.0 (IQR 12.5) and the main reason to NTZ discontinuation was progressive multifocal leukoencephalopathy (PML) risk (70%). After NTZ suspension, reactivation was observed in 25 (36%) patients after a median time of 20.0 (IQR 29.0) weeks. Reactivation predictors in our sample included NTZ suspension for reasons other than PML (adjusted HR = 0.228, 95% CI [0.084- 0.616], p = 0.004), ARR before NTZ (adjusted HR = 1.914 95% [CI 1.330-2.754], p < 0.001) and a longer disease duration at time of NTZ initiation (adjusted HR = 1.154, 95% CI [1.020-1.306], p = 0.023). Rebound occurred in 5 (7%) patients after a median time of 20 (IQR 34.5) weeks. Conclusion: Significant predictors of disease reactivation in our cohort were discontinuation of NTZ for reasons other than PML risk, higher disease activity before NTZ treatment, and longer disease duration. Our study provides valuable data of portuguese patients after NTZ withdrawal.info:eu-repo/semantics/publishedVersio

    Chitosan micro-membranes with integrated gold nanoparticles as an LSPR-based sensing platform

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    Currently, there is an increasing need to develop highly sensitive plasmonic sensors able to provide good biocompatibility, flexibility, and optical stability to detect low levels of analytes in biological media. In this study, gold nanoparticles (Au NPs) were dispersed into chitosan membranes by spin coating. It has been demonstrated that these membranes are particularly stable and can be successfully employed as versatile plasmonic platforms for molecular sensing. The optical response of the chitosan/Au NPs interfaces and their capability to sense the medium’s refractive index (RI) changes, either in a liquid or gas media, were investigated by high-resolution localized surface plasmon resonance (HR-LSPR) spectroscopy, as a proof of concept for biosensing applications. The results revealed that the lowest polymer concentration (chitosan (0.5%)/Au-NPs membrane) presented the most suitable plasmonic response. An LSPR band redshift was observed as the RI of the surrounding media was incremented, resulting in a sensitivity value of 28 ± 1 nm/RIU. Furthermore, the plasmonic membrane showed an outstanding performance when tested in gaseous atmospheres, being capable of distinguishing inert gases with only a 10−5 RI unit difference. The potential of chitosan/Au-NPs membranes was confirmed for application in LSPR-based sensing applications, despite the fact that further materials optimization should be performed to enhance sensitivity.This research was sponsored by the Portuguese Foundation for Science and Technology (FCT) in the framework of the Strategic Funding UIDB/04650/2020, by the project CO2Plasmon with reference EXPL/CTM-REF/0750/2021 and by the project with reference PTDC/CTM-CTM/2846/2020. Diana I. Meira acknowledges her Ph.D. Scholarship from FCT, with reference SFRH/BD/143262/2019. Manuela Proença acknowledges her Ph.D. Scholarship from FCT, with reference SFRH/BD/137076/2018

    Enhancing the longevity and functionality of Ti-Ag dry electrodes for remote biomedical applications: a comprehensive study

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    This study aims to evaluate the lifespan of Ti-Ag dry electrodes prepared using flexible polytetrafluoroethylene (PTFE) substrates. Following previous studies, the electrodes were designed to be integrated into wearables for remote electromyography (EMG) monitoring and electrical stimulation (FES) therapy. Four types of Ti-Ag electrodes were prepared by DC magnetron sputtering, using a pure-Ti target doped with a growing number of Ag pellets. After extensive characterization of their chemical composition and (micro)structural evolution, the Ti-Ag electrodes were immersed in an artificial sweat solution (standard ISO-3160-2) at 37 °C with constant stirring. Results revealed that all the Ti-Ag electrodes maintained their integrity and functionality for 24 h. Although there was a notable increase in electrical resistivity beyond this timeframe, the acquisition and transmission of (bio)signals remained viable for electrodes with Ag/Ti ratios below 0.23. However, electrodes with higher Ag content (Ag/Ti = 0.31) became insulators after 7 days of immersion due to excessive Ag release into the sweat solution. This study concludes that higher Ag/Ti atomic ratios result in heightened corrosion processes on the electrode’s surface, consequently diminishing their lifespan despite the advantages of incorporating Ag into their composition. This research highlights the critical importance of evaluating electrode longevity, especially in remote biomedical applications like smart wearables, where electrode performance over time is crucial for reliable and sustained monitoring and stimulation.This research was funded by the European Regional Development Fund (ERDF) through the Operational Programme for Competitiveness and Internationalization (COMPETE 2020) under Portugal 2020, in the framework of the NanoStim (POCI-01-0247-FEDER-045908) and NanoID (NORTE-01-0247-FEDER-046985) Projects
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