1,069 research outputs found

    Amperometric enzyme sensor for the rapid determination of histamine

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    The concentration of histamine, a biogenic amine, in fish is considered a fish spoilage indicator. Therefore, the development of a rapid-response and portable tool that allows its on-site analysis is very interesting since the consumption of high amounts of histamine causes scombroid poisoning. Thus, in this work a simple enzymatic sensor for the determination of histamine, based on a screen-printed carbon electrode and the enzyme diamine oxidase, was developed. The enzyme was immobilized on the electrode surface through a simple cross-linking procedure employing glutaraldehyde and bovine serum albumin. Chronoamperometry was used as the detection technique; the sensor showed a short response time (60 s, -0.3 V) and the measurements were performed by only using 40 ÎŒL of sample solution. The sensor provides an useful linear range (between 1 and 75 mg L-1 in fish extract), excellent reproducibility (RSD = 2.6%) and is reusable for up to 7 measurements. The feasibility of the sensor was tested performing histamine analysis in fish extracts achieving recovery values of 103%.The authors are grateful for the financial support from FCT/MEC through national funds and co-financed by FEDER, under the Partnership Agreement PT2020 through the project UID/ QUI/50006/2013. The authors would also like to thank the EU and FCT for funding through the projects: FishBioSensing - Portable electrochemical (bio)sensing devices for safety and quality assessment of fishery products (02/SAICT/2016, POCI-01-0145-FEDER-023817) and FOODnanoHEALTH - Qualidade e Segurança Alimentar – uma abordagem (nano)tecnolĂłgica (Portugal2020, Norte-01-0145-FEDER-000011).info:eu-repo/semantics/publishedVersio

    Disposable electrochemical immunosensor for analysis of cystatin C, a CKD biomarker

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    Specific monitoring of cystatin C (CysC) levels in biological fluids is critical for diagnosis, treatment and mechanistic understanding of a spectrum of diseases, particularly chronic kidney disease (CKD). Despite evidences that CysC correlates with the high risk and/or progression of CKD, its use in clinical practice is still scarce. In this context, we report the development of a simple and sensitive immunosensor for the detection of CysC. The biosensor combines the technology of cost-effective screen-printed electrodes with the high specificity of a sandwich immunoassay. Optimized conditions showed that the sensor operates in a linear range between 10 and 100 ng mL-1, with a detection limit and a sensitivity of 6.0 ng mL-1 and 6.4 ± 0.3â€ŻÎŒA ng mL-1 cm-2, respectively. Moreover, the sensor provided precise results (RSD ≀ 6.2%) and the quantification of CysC in CKD serum samples revealed to be in agreement with the values obtained by a particle-enhanced nephelometric immunoassay. In this light, the proposed immunosensor qualifies for clinical application, constituting a step forward in the development of fast, sensitive and cost-effective diagnostic tools that can improve the current medical care settings of CKD patients.This work was supported by European Union through projects Norte-01-0145-FEDER-000024 and Norte-01-0145-FEDER-000011, co-funded by FEDER in the scope of CCDR-N and NORTE2020 Partnership Agreement. This work also received financial support from the European Union (FEDER funds through COMPETE) and National Funds (FCT, Fundação para a CiĂȘncia e a Tecnologia) through project UID/QUI/50006/2013.info:eu-repo/semantics/publishedVersio

    Quality of agricultural software: a case study

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    The quality of an agropecuary software is essential to conduct the user to extract the expected advantages of its use. A case study for the evaluation of caracteristics and sub-caracteristics of the quality of the commercial software product for the management of beef cattles was performed. It was conclude that the software is considered acceptable.A qualidade de um software agropecuårio é fundamental para conduzir o usuårio a extrair os benefícios esperados com a sua utilização. Fez-se um estudo de caso para a avaliação de características e sub-características de qualidade de um produto de software comercial destinado ao gerenciamento de rebanhos bovinos. Concluiu-se que o software foi considerado aceitåvel

    Microbes as engines of ecosystem function : When does community structure enhance predictions of ecosystem processes?

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    FUNDING This work was supported by NSF grant DEB-1221215 to DN, as well as grants supporting the generation of our datasets as acknowledged in their original publications and in Supplementary Table S1. ACKNOWLEDGMENT We thank the USGS Powell Center ‘Next Generation Microbes’ working group, anonymous reviews, Brett Melbourne, and Alan Townsend for valuable feedback on this project.Peer reviewedPublisher PD

    Pré-eclùmpsia : rastreamento universal ou prevenção universal para países de baixa e média-renda?

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    Pre-eclampsia (PE) is a severe disorder that affects up to 8% of all pregnancies and represents an important cause of maternal and perinatal morbidity and mortality. The screening of the disease is a subject of studies, but the complexity and uncertainties regarding its etiology make this objective a difficult task. In addition, the costs related to screening protocols, the heterogeneity of the most affected populations and the lack of highly effective prevention methods reduce the potential of current available algorithms for screening. Thus, the National Specialized Commission of Hypertension in Pregnancy of the Brazilian Association of Gynecology and Obstetrics Federation (Febrasgo, in the Portuguese acronym) (NSC Hypertension in Pregnancy of the Febrasgo) considers that there are no screening algorithms to be implemented in the country to date and advocates that Aspirin and calcium should be widely used.A Pré-eclùmpsia (PE) é uma doença grave que acomete ~8% das gestaçÔes e representa importante causa de morbimortalidade, tanto materna quanto perinatal. O rastreamento da doença émotivo de estudos, porém a complexidade e as incertezas quanto a sua etiologia tornam esse objetivo bastante difícil. Além disso, os custos relacionados com o rastreamento, a heterogeneidade das populaçÔes mais afetadas e ainda a falta de métodos de prevenção de grande eficåcia reduzem o potencial dos algoritmos de rastreamento. Assim, a Comissão Nacional Especializada sobre Hipertensão na Gravidez da Federação Brasileira das AssociaçÔes de Ginecologia e Obstetrícia (CNE Hipertensão na Gravidez da FEBRASGO) considera que não hå algoritmos de rastreamento que possam ser aplicados no país nesse momento e defende a utilização dos métodos de prevenção como åcido acetilsalicílico e cålcio de maneira ampla

    Pré-eclùmpsia/Eclùmpsia

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    Pre-eclampsia is a multifactorial and multisystemic disease specific to gestation. It is classically diagnosed by the presence of hypertension associated with proteinuria manifested in a previously normotensive pregnant woman after the 20th week of gestation. Pre-eclampsia is also considered in the absence of proteinuria if there is target organ damage. The present review takes a general approach focused on aspects of practical interest in the clinical and obstetric care of these women. Thus, it explores the still unknown etiology, current aspects of pathophysiology and of the diagnosis, the approach to disease prediction, its adverse outcomes and prevention. Management is based on general principles, on nonpharmacological and on pharmacological clinical treatment of severe or nonsevere situations with emphasis on the hypertensive crisis and eclampsia. Obstetric management is based on preeclampsia without or with signs of clinical and/or laboratory deterioration, stratification of gestational age in < 24 weeks, between 24 and less than 34 weeks, and ≄ 34 weeks of gestation, and guidance on route of delivery. An immediate puerperium approach and repercussions in the future life of pregnant women who develop preeclampsia is also presented.A prĂ©-eclĂąmpsia Ă© uma doença multifatorial e multissistĂȘmica especĂ­fica da gestação. É classicamente diagnosticada pela presença de hipertensĂŁo arterial associada Ă  proteinĂșria em gestante previamente normotensa apĂłs a 20a semana de gestação. A prĂ©-eclĂąmpsia tambĂ©m Ă© considerada na ausĂȘncia de proteinĂșria se houver lesĂŁo de ĂłrgĂŁo-alvo. A presente revisĂŁo tem uma abordagem geral focada em aspectos de interesse prĂĄtico na assistĂȘncia clĂ­nica e obstĂ©trica dessas mulheres. Assim, explora a etiologia ainda desconhecida, aspectos atuais da fisiopatologia e do diagnĂłstico e diagnĂłstico diferencial de convulsĂ”es, a abordagem da predição da doença, seus resultados adversos e prevenção. A conduta baseia-se em princĂ­pios gerais, tratamento clĂ­nico nĂŁo farmacolĂłgico e farmacolĂłgico de situaçÔes graves ou nĂŁo graves, com ĂȘnfase na crise hipertensiva e eclĂąmpsia. O controle obstĂ©trico se fundamenta na prĂ©-eclĂąmpsia sem ou com sinais de deterioração clĂ­nica e/ou laboratorial, estratificação da idade gestacional abaixo de 24 semanas, entre 24 e menos de 34 semanas e 34 ou mais semanas de gestação e orientação na via de parto. Uma abordagem imediata do puerpĂ©rio e repercussĂ”es na vida futura de gestantes que desenvolvem prĂ©-eclĂąmpsia tambĂ©m foram apresentadas

    Ultrasound-guided breast-sparing surgery to improve cosmetic outcomes and quality of life. A prospective multicentre randomised controlled clinical trial comparing ultrasound-guided surgery to traditional palpation-guided surgery (COBALT trial)

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    <p>Abstract</p> <p>Background</p> <p>Breast-conserving surgery for breast cancer was developed as a method to preserve healthy breast tissue, thereby improving cosmetic outcomes. Thus far, the primary aim of breast-conserving surgery has been the achievement of tumour-free resection margins and prevention of local recurrence, whereas the cosmetic outcome has been considered less important. Large studies have reported poor cosmetic outcomes in 20-40% of patients after breast-conserving surgery, with the volume of the resected breast tissue being the major determinant. There is clear evidence for the efficacy of ultrasonography in the resection of nonpalpable tumours. Surgical resection of palpable breast cancer is performed with guidance by intra-operative palpation. These palpation-guided excisions often result in an unnecessarily wide resection of adjacent healthy breast tissue, while the rate of tumour-involved resection margins is still high. It is hypothesised that the use of intra-operative ultrasonography in the excision of palpable breast cancer will improve the ability to spare healthy breast tissue while maintaining or even improving the oncological margin status. The aim of this study is to compare ultrasound-guided surgery for palpable tumours with the standard palpation-guided surgery in terms of the extent of healthy breast tissue resection, the percentage of tumour-free margins, cosmetic outcomes and quality of life.</p> <p>Methods/design</p> <p>In this prospective multicentre randomised controlled clinical trial, 120 women who have been diagnosed with palpable early-stage (T1-2N0-1) primary invasive breast cancer and deemed suitable for breast-conserving surgery will be randomised between ultrasound-guided surgery and palpation-guided surgery. With this sample size, an expected 20% reduction of resected breast tissue and an 18% difference in tumour-free margins can be detected with a power of 80%. Secondary endpoints include cosmetic outcomes and quality of life. The rationale, study design and planned analyses are described.</p> <p>Conclusion</p> <p>The COBALT trial is a prospective, multicentre, randomised controlled study to assess the efficacy of ultrasound-guided breast-conserving surgery in patients with palpable early-stage primary invasive breast cancer in terms of the sparing of breast tissue, oncological margin status, cosmetic outcomes and quality of life.</p> <p>Trial Registration Number</p> <p>Netherlands Trial Register (NTR): <a href="http://www.trialregister.nl/trialreg/admin/rctview.asp?TC=2579">NTR2579</a></p
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