265 research outputs found
Metodologias Analíticas Inovadoras Baseadas em Microextração Adsortiva em Barra (BAμE) para a Monitorização de Contaminantes e Substâncias de Abuso Emergentes em Matrizes Ambientais e Biológicas
A monitorização vestigial de contaminantes e substâncias de abuso emergentes em matrizes ambientais e biológicas é uma tarefa de grande relevância na sociedade contemporânea, exigindo sempre uma etapa de ‘preparação da amostra’ prévia à análise instrumental. Neste contexto, são recorrentemente adotadas técnicas de microextração que promovam o enriquecimento dos analitos alvo por forma a incrementar a sensibilidade e a seletividade das metodologias analíticas.
As técnicas de microextração estática têm vindo a adquirir notoriedade, uma vez que, para além de apresentarem bom desempenho e custo-benefício adequado, contemplam ainda os princípios da Química Analítica Verde. A técnica de microextração adsortiva em barra (BAμE), em particular, destaca-se das demais, uma vez permitir selecionar a melhor fase sorvente para determinada aplicação, apresentar elevada simplicidade e robustez, para além de comprovada eficácia no enriquecimento de classes de compostos com diferentes propriedades físico-químicas em diversos tipos de matrizes.
A presente dissertação propõe metodologias analíticas inovadoras baseadas em BAμE para a monitorização vestigial de contaminantes (ex., produtos farmacêuticos e de higiene pessoal, etc.), bem como de substâncias de abuso (ex., canabinóides sintéticos, etc.) emergentes em matrizes ambientais (ex., água estuarina, etc.) e biológicas (ex., urina, etc.). Durante o desenvolvimento, foram introduzidos diversos avanços por forma a melhorar o desempenho analítico da técnica, em particular com recurso a novos materiais sorventes (ex., hidrocarbonizados porosos, etc.) para revestimento dos dispositivos, assim como a introdução de uma nova configuração experimental, a BAμE de alto rendimento (HT-BAμE). Esta abordagem inovadora possibilita, de forma simples e conveniente, a microextração e subsequente retroextração de até 100 amostras em simultâneo. Globalmente, os resultados demonstraram que as metodologias propostas são simples, amigas do ambiente e com custobenefício vantajoso. As inovações propostas evidenciaram grande abrangência, versatilidade, eficiência e robustez, sendo alternativas inequívocas sempre que as aplicações exijam tomadas de decisão rápidas
Micro-extração adsortiva aplicada na análise de esteróides anabólicos em contexto de controlo anti-doping
Tese de mestrado em Bioquímica, apresentada à Universidade de Lisboa, através da Faculdade de Ciências, 2013A testosterona é uma das substâncias mais abusadas por atletas em todo o mundo. Por forma a controlar a sua administração exógena, a Agência Mundial de Antidopagem (WADA) produziu diretivas para se proceder à respetiva análise, que combinam um passo de extração e outro de derivatização, que permitam a análise posterior por cromatografia em fase gasosa acoplada à espectrometria de massa. No entanto, face ao elevado tempo despendido, assim como à utilização de solventes orgânicos tóxicos, é
necessário o desenvolvimento de métodos analíticos alternativos que permitam a diminuição do consumo de solventes e eliminação do passo de derivatização, mantendo ou melhorando o desempenho analítico.
O presente trabalho consistiu no desenvolvimento, otimização, validação e aplicação de um método inovador, alicerçado na tecnologia de amostragem por flutuação, para a determinação de testosterona e epitestosterona em matrizes de urina. Por conseguinte, recorreu-se à técnica de micro-extração adsortiva em barra seguida de dessorção líquida e análise por cromatografia líquida de alta eficiência com deteção por rede de díodos (BAμE-LD/HPLC-DAD).
Para otimização da metodologia desenvolvida, foram efetuados diversos estudos sistemáticos a vários parâmetros experimentais, tendo-se verificado que o co-polímero modificado à base de pirrolidona e divenilbenzeno (P1) demonstrava melhor seletividade comparativamente com outras fases. Em condições experimentais otimizadas (extração: 16 h (1000 rpm), pH 5,5; retro-extração: acetonitrilo (30 min), sob tratamento ultrassónico) foi possível obter recuperações médias de 92,1 e 93,4 % para testosterona e epitestosterona, respetivamente. O método revelou ainda, excelente linearidade (r2 > 0,9978) na gama compreendida entre 1,4 e 16,0 μg/L, tendo-se alcançado, para ambos os compostos, limites de deteção e de quantificação de 0,40 e 1,32 μg/L, respetivamente.
O recurso ao método de adição padrão permitiu a aplicação da presente metodologia a amostras de urina, demonstrando bom desempenho analítico para a determinação dos compostos em estudo. A metodologia proposta (BAμE(P1)-LD/HPLC-DAD) revelou ainda ser uma estratégia alternativa para a análise de testosterona e epitestosterona como ferramenta para análise de rotina em contexto de controlo anti-doping, apresentando como principais vantagens a utilização de pequenas quantidades de amostra e solvente, tempo analítico reduzido e fácil manipulação, associada à rapidez, simplicidade e bom desempenho analítico.Testosterone is one of the most abused substances by athletes worldwide. In order to control its exogenous administration, the World Anti-Doping Agency (WADA) produced guidelines to proceed to its analysis, that combine an extraction followed by a derivatization step, which allows the analysis by gas chromatography coupled to mass spectrometry. However, in face of the long analytical process, as well as the usage of toxic organic solvents, it is necessary to develop alternative analytical methods that allow the diminishment of solvent consumption and elimination of the derivatization step, maintaining or improving the analytical performance.
The present work consisted in the development, optimization, validation and application of a novel method, based on the “Floating Sampling Technology”, for the determination of testosterone and epitestosterone in urine matrices. Thus, bar adsorptive micro-extraction technique was used, followed by liquid desorption and analysis by high performance liquid chromatography with diode array detection (BAμE-LD/HPLCDAD). For optimization of the developed methodology, systematic studies have been performed to several experimental parameters, where the modified copolymer based on pyrrolidone and divenilbenzene (P1) presented better selectivity in comparison with other phases. Under optimized experimental conditions (extraction: 16 h (1000 rpm), pH 5.5; back-extraction: acetonitrile (30 min), under sonification), it was possible to obtain average efficiencies of 92.1 and 93.4 % for testosterone and epitestosterone, respectively. The method also revealed excellent linearity (r2 > 0.9978) in the range between 1.40 and 16.0 μg/L, having reached for both substances, limits of detection and quantification of 0.40 and 1.32 μg/L, respectively.
The use of the standard addition method allowed the application of this methodology to urine samples, in which good analytical performance was achieved for the occurrence of the target compounds. The proposed method BAμE(P1)-LD/HPLCDAD proved to be a good alternative strategy for the analysis of testosterone and epitestosterone as a routine analytical tool in the context of anti-doping control, having as its main advantages the use of small amounts of sample and solvent, reduced analytical time and easy manipulation, associated with a fast, simple and good analytical performance
Burnout among surgeons before and during the SARS-CoV-2 pandemic: an international survey
Background: SARS-CoV-2 pandemic has had many significant impacts within the surgical realm, and surgeons have been obligated to reconsider almost every aspect of daily clinical practice. Methods: This is a cross-sectional study reported in compliance with the CHERRIES guidelines and conducted through an online platform from June 14th to July 15th, 2020. The primary outcome was the burden of burnout during the pandemic indicated by the validated Shirom-Melamed Burnout Measure. Results: Nine hundred fifty-four surgeons completed the survey. The median length of practice was 10 years; 78.2% included were male with a median age of 37 years old, 39.5% were consultants, 68.9% were general surgeons, and 55.7% were affiliated with an academic institution. Overall, there was a significant increase in the mean burnout score during the pandemic; longer years of practice and older age were significantly associated with less burnout. There were significant reductions in the median number of outpatient visits, operated cases, on-call hours, emergency visits, and research work, so, 48.2% of respondents felt that the training resources were insufficient. The majority (81.3%) of respondents reported that their hospitals were included in the management of COVID-19, 66.5% felt their roles had been minimized; 41% were asked to assist in non-surgical medical practices, and 37.6% of respondents were included in COVID-19 management. Conclusions: There was a significant burnout among trainees. Almost all aspects of clinical and research activities were affected with a significant reduction in the volume of research, outpatient clinic visits, surgical procedures, on-call hours, and emergency cases hindering the training. Trial registration: The study was registered on clicaltrials.gov "NCT04433286" on 16/06/2020
Impact of opioid-free analgesia on pain severity and patient satisfaction after discharge from surgery: multispecialty, prospective cohort study in 25 countries
Background: Balancing opioid stewardship and the need for adequate analgesia following discharge after surgery is challenging. This study aimed to compare the outcomes for patients discharged with opioid versus opioid-free analgesia after common surgical procedures.Methods: This international, multicentre, prospective cohort study collected data from patients undergoing common acute and elective general surgical, urological, gynaecological, and orthopaedic procedures. The primary outcomes were patient-reported time in severe pain measured on a numerical analogue scale from 0 to 100% and patient-reported satisfaction with pain relief during the first week following discharge. Data were collected by in-hospital chart review and patient telephone interview 1 week after discharge.Results: The study recruited 4273 patients from 144 centres in 25 countries; 1311 patients (30.7%) were prescribed opioid analgesia at discharge. Patients reported being in severe pain for 10 (i.q.r. 1-30)% of the first week after discharge and rated satisfaction with analgesia as 90 (i.q.r. 80-100) of 100. After adjustment for confounders, opioid analgesia on discharge was independently associated with increased pain severity (risk ratio 1.52, 95% c.i. 1.31 to 1.76; P < 0.001) and re-presentation to healthcare providers owing to side-effects of medication (OR 2.38, 95% c.i. 1.36 to 4.17; P = 0.004), but not with satisfaction with analgesia (beta coefficient 0.92, 95% c.i. -1.52 to 3.36; P = 0.468) compared with opioid-free analgesia. Although opioid prescribing varied greatly between high-income and low- and middle-income countries, patient-reported outcomes did not.Conclusion: Opioid analgesia prescription on surgical discharge is associated with a higher risk of re-presentation owing to side-effects of medication and increased patient-reported pain, but not with changes in patient-reported satisfaction. Opioid-free discharge analgesia should be adopted routinely
Impact of COVID-19 on cardiovascular testing in the United States versus the rest of the world
Objectives: This study sought to quantify and compare the decline in volumes of cardiovascular procedures between the United States and non-US institutions during the early phase of the coronavirus disease-2019 (COVID-19) pandemic.
Background: The COVID-19 pandemic has disrupted the care of many non-COVID-19 illnesses. Reductions in diagnostic cardiovascular testing around the world have led to concerns over the implications of reduced testing for cardiovascular disease (CVD) morbidity and mortality.
Methods: Data were submitted to the INCAPS-COVID (International Atomic Energy Agency Non-Invasive Cardiology Protocols Study of COVID-19), a multinational registry comprising 909 institutions in 108 countries (including 155 facilities in 40 U.S. states), assessing the impact of the COVID-19 pandemic on volumes of diagnostic cardiovascular procedures. Data were obtained for April 2020 and compared with volumes of baseline procedures from March 2019. We compared laboratory characteristics, practices, and procedure volumes between U.S. and non-U.S. facilities and between U.S. geographic regions and identified factors associated with volume reduction in the United States.
Results: Reductions in the volumes of procedures in the United States were similar to those in non-U.S. facilities (68% vs. 63%, respectively; p = 0.237), although U.S. facilities reported greater reductions in invasive coronary angiography (69% vs. 53%, respectively; p < 0.001). Significantly more U.S. facilities reported increased use of telehealth and patient screening measures than non-U.S. facilities, such as temperature checks, symptom screenings, and COVID-19 testing. Reductions in volumes of procedures differed between U.S. regions, with larger declines observed in the Northeast (76%) and Midwest (74%) than in the South (62%) and West (44%). Prevalence of COVID-19, staff redeployments, outpatient centers, and urban centers were associated with greater reductions in volume in U.S. facilities in a multivariable analysis.
Conclusions: We observed marked reductions in U.S. cardiovascular testing in the early phase of the pandemic and significant variability between U.S. regions. The association between reductions of volumes and COVID-19 prevalence in the United States highlighted the need for proactive efforts to maintain access to cardiovascular testing in areas most affected by outbreaks of COVID-19 infection
Severe early onset preeclampsia: short and long term clinical, psychosocial and biochemical aspects
Preeclampsia is a pregnancy specific disorder commonly defined as de novo hypertension
and proteinuria after 20 weeks gestational age. It occurs in approximately 3-5% of pregnancies and it is still a major cause of both foetal and maternal morbidity and mortality worldwide1. As extensive research has not yet elucidated the aetiology of preeclampsia, there are no rational preventive or therapeutic interventions
available. The only rational treatment is delivery, which benefits the mother but is not in the interest of the foetus, if remote from term. Early onset preeclampsia (<32 weeks’ gestational age) occurs in less than 1% of pregnancies. It is, however often associated with maternal morbidity as the risk of progression
to severe maternal disease is inversely related with gestational age at onset2. Resulting prematurity is therefore the main cause of neonatal mortality and morbidity
in patients with severe preeclampsia3. Although the discussion is ongoing, perinatal survival is suggested to be increased in patients with preterm preeclampsia
by expectant, non-interventional management. This temporising treatment option to lengthen pregnancy includes the use of antihypertensive medication to control hypertension, magnesium sulphate to prevent eclampsia and corticosteroids
to enhance foetal lung maturity4. With optimal maternal haemodynamic status and reassuring foetal condition this results on average in an extension of 2 weeks. Prolongation of these pregnancies is a great challenge for clinicians to balance between potential maternal risks on one the eve hand and possible foetal benefits on the other. Clinical controversies regarding prolongation of preterm preeclamptic pregnancies still exist – also taking into account that preeclampsia is the leading cause of maternal mortality in the Netherlands5 - a debate which is even more pronounced in very preterm pregnancies with questionable foetal viability6-9. Do maternal risks of prolongation of these very early pregnancies outweigh
the chances of neonatal survival? Counselling of women with very early onset preeclampsia not only comprises of knowledge of the outcome of those particular pregnancies, but also knowledge of outcomes of future pregnancies of these women is of major clinical importance.
This thesis opens with a review of the literature on identifiable risk factors of preeclampsia
Mapping local patterns of childhood overweight and wasting in low- and middle-income countries between 2000 and 2017
A double burden of malnutrition occurs when individuals, household members or communities experience both undernutrition and overweight. Here, we show geospatial estimates of overweight and wasting prevalence among children under 5 years of age in 105 low- and middle-income countries (LMICs) from 2000 to 2017 and aggregate these to policy-relevant administrative units. Wasting decreased overall across LMICs between 2000 and 2017, from 8.4% (62.3 (55.1–70.8) million) to 6.4% (58.3 (47.6–70.7) million), but is predicted to remain above the World Health Organization’s Global Nutrition Target of <5% in over half of LMICs by 2025. Prevalence of overweight increased from 5.2% (30 (22.8–38.5) million) in 2000 to 6.0% (55.5 (44.8–67.9) million) children aged under 5 years in 2017. Areas most affected by double burden of malnutrition were located in Indonesia, Thailand, southeastern China, Botswana, Cameroon and central Nigeria. Our estimates provide a new perspective to researchers, policy makers and public health agencies in their efforts to address this global childhood syndemic
Why Are Outcomes Different for Registry Patients Enrolled Prospectively and Retrospectively? Insights from the Global Anticoagulant Registry in the FIELD-Atrial Fibrillation (GARFIELD-AF).
Background: Retrospective and prospective observational studies are designed to reflect real-world evidence on clinical practice, but can yield conflicting results. The GARFIELD-AF Registry includes both methods of enrolment and allows analysis of differences in patient characteristics and outcomes that may result. Methods and Results: Patients with atrial fibrillation (AF) and ≥1 risk factor for stroke at diagnosis of AF were recruited either retrospectively (n = 5069) or prospectively (n = 5501) from 19 countries and then followed prospectively. The retrospectively enrolled cohort comprised patients with established AF (for a least 6, and up to 24 months before enrolment), who were identified retrospectively (and baseline and partial follow-up data were collected from the emedical records) and then followed prospectively between 0-18 months (such that the total time of follow-up was 24 months; data collection Dec-2009 and Oct-2010). In the prospectively enrolled cohort, patients with newly diagnosed AF (≤6 weeks after diagnosis) were recruited between Mar-2010 and Oct-2011 and were followed for 24 months after enrolment. Differences between the cohorts were observed in clinical characteristics, including type of AF, stroke prevention strategies, and event rates. More patients in the retrospectively identified cohort received vitamin K antagonists (62.1% vs. 53.2%) and fewer received non-vitamin K oral anticoagulants (1.8% vs . 4.2%). All-cause mortality rates per 100 person-years during the prospective follow-up (starting the first study visit up to 1 year) were significantly lower in the retrospective than prospectively identified cohort (3.04 [95% CI 2.51 to 3.67] vs . 4.05 [95% CI 3.53 to 4.63]; p = 0.016). Conclusions: Interpretations of data from registries that aim to evaluate the characteristics and outcomes of patients with AF must take account of differences in registry design and the impact of recall bias and survivorship bias that is incurred with retrospective enrolment. Clinical Trial Registration: - URL: http://www.clinicaltrials.gov . Unique identifier for GARFIELD-AF (NCT01090362)
Measuring performance on the Healthcare Access and Quality Index for 195 countries and territories and selected subnational locations: A systematic analysis from the Global Burden of Disease Study 2016
Background: A key component of achieving universal health coverage is ensuring that all populations have access to quality health care. Examining where gains have occurred or progress has faltered across and within countries is crucial to guiding decisions and strategies for future improvement. We used the Global Burden of Diseases, Injuries, and Risk Factors Study 2016 (GBD 2016) to assess personal health-care access and quality with the Healthcare Access and Quality (HAQ) Index for 195 countries and territories, as well as subnational locations in seven countries, from 1990 to 2016. Methods Drawing from established methods and updated estimates from GBD 2016, we used 32 causes from which death should not occur in the presence of effective care to approximate personal health-care access and quality by location and over time. To better isolate potential effects of personal health-care access and quality from underlying risk factor patterns, we risk-standardised cause-specific deaths due to non-cancers by location-year, replacing the local joint exposure of environmental and behavioural risks with the global level of exposure. Supported by the expansion of cancer registry data in GBD 2016, we used mortality-to-incidence ratios for cancers instead of risk-standardised death rates to provide a stronger signal of the effects of personal health care and access on cancer survival. We transformed each cause to a scale of 0-100, with 0 as the first percentile (worst) observed between 1990 and 2016, and 100 as the 99th percentile (best); we set these thresholds at the country level, and then applied them to subnational locations. We applied a principal components analysis to construct the HAQ Index using all scaled cause values, providing an overall score of 0-100 of personal health-care access and quality by location over time. We then compared HAQ Index levels and trends by quintiles on the Socio-demographic Index (SDI), a summary measure of overall development. As derived from the broader GBD study and other data sources, we examined relationships between national HAQ Index scores and potential correlates of performance, such as total health spending per capita. Findings In 2016, HAQ Index performance spanned from a high of 97\ub71 (95% UI 95\ub78-98\ub71) in Iceland, followed by 96\ub76 (94\ub79-97\ub79) in Norway and 96\ub71 (94\ub75-97\ub73) in the Netherlands, to values as low as 18\ub76 (13\ub71-24\ub74) in the Central African Republic, 19\ub70 (14\ub73-23\ub77) in Somalia, and 23\ub74 (20\ub72-26\ub78) in Guinea-Bissau. The pace of progress achieved between 1990 and 2016 varied, with markedly faster improvements occurring between 2000 and 2016 for many countries in sub-Saharan Africa and southeast Asia, whereas several countries in Latin America and elsewhere saw progress stagnate after experiencing considerable advances in the HAQ Index between 1990 and 2000. Striking subnational disparities emerged in personal health-care access and quality, with China and India having particularly large gaps between locations with the highest and lowest scores in 2016. In China, performance ranged from 91\ub75 (89\ub71-93\ub76) in Beijing to 48\ub70 (43\ub74-53\ub72) in Tibet (a 43\ub75-point difference), while India saw a 30\ub78-point disparity, from 64\ub78 (59\ub76-68\ub78) in Goa to 34\ub70 (30\ub73-38\ub71) in Assam. Japan recorded the smallest range in subnational HAQ performance in 2016 (a 4\ub78-point difference), whereas differences between subnational locations with the highest and lowest HAQ Index values were more than two times as high for the USA and three times as high for England. State-level gaps in the HAQ Index in Mexico somewhat narrowed from 1990 to 2016 (from a 20\ub79-point to 17\ub70-point difference), whereas in Brazil, disparities slightly increased across states during this time (a 17\ub72-point to 20\ub74-point difference). Performance on the HAQ Index showed strong linkages to overall development, with high and high-middle SDI countries generally having higher scores and faster gains for non-communicable diseases. Nonetheless, countries across the development spectrum saw substantial gains in some key health service areas from 2000 to 2016, most notably vaccine-preventable diseases. Overall, national performance on the HAQ Index was positively associated with higher levels of total health spending per capita, as well as health systems inputs, but these relationships were quite heterogeneous, particularly among low-to-middle SDI countries. Interpretation GBD 2016 provides a more detailed understanding of past success and current challenges in improving personal health-care access and quality worldwide. Despite substantial gains since 2000, many low-SDI and middle- SDI countries face considerable challenges unless heightened policy action and investments focus on advancing access to and quality of health care across key health services, especially non-communicable diseases. Stagnating or minimal improvements experienced by several low-middle to high-middle SDI countries could reflect the complexities of re-orienting both primary and secondary health-care services beyond the more limited foci of the Millennium Development Goals. Alongside initiatives to strengthen public health programmes, the pursuit of universal health coverage hinges upon improving both access and quality worldwide, and thus requires adopting a more comprehensive view-and subsequent provision-of quality health care for all populations
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