23 research outputs found

    VORTEX FORMATION IN INCOMPRESSIBLE AXISYMMETRIC FREE JETS

    Get PDF
    Free jets have been utilized extensively in many industrial applications. In general jet fluid discharging from a nozzle develops flow oscillations in the shear layer. The oscillations will roll up to eventually become toroidal vortices which increase in size with the axial distance from the nozzle. In the present work, flow visualization as well as hot-film anemometry have been employed in order to study incompressible axisymmetric free jet in moderate Reynolds numbers up to 20,000. The injection of liquid dye or micro particles associated with a laser sheet turns possible to visualize the shear layers and, consequently, the vortex formation. Hot-film measurements into the jet allow determining the flow velocity profile. Flow visualization is a qualitative tool which a broad view of the flow topology. On the other hand, hot-film anemometry is a precise quantitative tool but measurement in only one location at a time. The association of flow visualization and hot-film anemometry shows very adequate for free jet studies

    Change in cervical length after arrested preterm labor and the risk of preterm birth

    Get PDF
    ACKNOWLEDGMENTS B.W.J.M. is supported by a NHMRC Investigator grant (GNT1176437). B.W.J.M. reports consultancy for Guerbet, has been a member of the ObsEva advisory board and holds stock options for ObsEva. B.W.J.M. has received research funding from Guerbet and Merck.Peer reviewedPublisher PD

    Physiological quality, content and activity of antioxidants in soybean seeds artificially aged.

    Get PDF
    ABSTRACT - The objective of this study was to evaluate physiological quality, content, and activity of antioxidants, in soybean seeds subjected to accelerated aging during different periods. Seeds of cultivars BRS 258, BRS 262 and BRS 268, subjected to accelerated aging during 12, 24, 36 and 48 hours and non-aged seeds were used. After each aging period, the seed were evaluated by tests of: germination; first count and tetrazolium. The total of phenolic compounds, total flavonoides, total of isoflavones, and activity for eliminating ABTS°+ radicals were quantified. There were differences among cultivars according to vigor and viability only after seeds were aged. Cultivars BRS 158 and BRS 268 have shown better seed physiological quality in each aging period; however, not presenting higher amounts of isoflavones and efficiency in removing free radicals. For all cultivars, the values for total of phenolic compounds, as well as total of flavonoids have shown quadratic positive behavior; the values for isoflavones remained constant and the vigor and viability showed contrary trend to activity of antioxidant agents. RESUMO: Qualidade fisiológica, conteúdo e atividade de antioxidantes presentes em sementes de soja envelhecidas artificialmente. O objetivo deste trabalho foi avaliar a qualidade fisiológica, o conteúdo e a atividade de agentes antioxidantes presentes em sementes de soja envelhecidas durante diferentes períodos. Foram utilizadas sementes das cultivares BRS 258, BRS 262 e BRS 268, envelhecidas durante 12, 24, 36 e 48 h e sementes não envelhecidas. Após cada período de envelhecimento, as sementes foram avaliadas pelo testes de: germinação; primeira contagem e tetrazólio. Foram quantificados: compostos fenólicos totais; flavonóides totais; total de isoflavonas e atividade eliminadora do radical ABTS°+. Houve diferença entre as cultivares em relação ao vigor e viabilidade somente quando foram envelhecidas. BRS 158 e BRS 268 apresentaram melhor qualidade fisiológica de sementes em cada período de envelhecimento, porém, não apresentaram maior quantidade de isoflavonas e eficiência no sequestro dos radicais livres. Para todas as cultivares, os valores de compostos fenólicos totais, assim como os flavonóides totais, apresentaram comportamento quadrático positivo; os valores das isoflavonas permaneceram constantes e o vigor e a viabilidade apresentaram tendência contrária à atividade dos agentes antioxidantes

    Remifentanil patient controlled analgesia versus epidural analgesia in labour. A multicentre randomized controlled trial

    Get PDF
    Contains fulltext : 109349.pdf (publisher's version ) (Open Access)ABSTRACT: BACKGROUND: Pain relief during labour is a topic of major interest in the Netherlands. Epidural analgesia is considered to be the most effective method of pain relief and recommended as first choice. However its uptake by pregnant women is limited compared to other western countries, partly as a result of non-availability due to logistic problems. Remifentanil, a synthetic opioid, is very suitable for patient controlled analgesia. Recent studies show that epidural analgesia is superior to remifentanil patient controlled analgesia in terms of pain intensity score; however there was no difference in satisfaction with pain relief between both treatments. METHODS/DESIGN: The proposed study is a multicentre randomized controlled study that assesses the cost-effectiveness of remifentanil patient controlled analgesia compared to epidural analgesia. We hypothesize that remifentanil patient controlled analgesia is as effective in improving pain appreciation scores as epidural analgesia, with lower costs and easier achievement of 24 hours availability of pain relief for women in labour and efficient pain relief for those with a contraindication for epidural analgesia.Eligible women will be informed about the study and randomized before active labour has started. Women will be randomly allocated to a strategy based on epidural analgesia or on remifentanil patient controlled analgesia when they request pain relief during labour. Primary outcome is the pain appreciation score, i.e. satisfaction with pain relief.Secondary outcome parameters are costs, patient satisfaction, pain scores (pain-intensity), mode of delivery and maternal and neonatal side effects.The economic analysis will be performed from a short-term healthcare perspective. For both strategies the cost of perinatal care for mother and child, starting at the onset of labour and ending ten days after delivery, will be registered and compared. DISCUSSION: This study, considering cost effectiveness of remifentanil as first choice analgesia versus epidural analgesia, could strongly improve the care for 180.000 women, giving birth in the Netherlands yearly by giving them access to pain relief during labour, 24 hours a day. TRIAL REGISTRATION NUMBER: Dutch Trial Register NTR2551, http://www.trialregister.nl

    Analytical methods applied to diverse types of Brazilian propolis

    Get PDF
    Propolis is a bee product, composed mainly of plant resins and beeswax, therefore its chemical composition varies due to the geographic and plant origins of these resins, as well as the species of bee. Brazil is an important supplier of propolis on the world market and, although green colored propolis from the southeast is the most known and studied, several other types of propolis from Apis mellifera and native stingless bees (also called cerumen) can be found. Propolis is usually consumed as an extract, so the type of solvent and extractive procedures employed further affect its composition. Methods used for the extraction; analysis the percentage of resins, wax and insoluble material in crude propolis; determination of phenolic, flavonoid, amino acid and heavy metal contents are reviewed herein. Different chromatographic methods applied to the separation, identification and quantification of Brazilian propolis components and their relative strengths are discussed; as well as direct insertion mass spectrometry fingerprinting

    Child outcomes after amnioinfusion compared with no intervention in women with second-trimester rupture of membranes:a long-term follow-up study of the PROMEXIL-III trial

    Get PDF
    Objective: To assess the effect of transabdominal amnioinfusion or no intervention on long-term outcomes in children born after second-trimester prelabour rupture of the membranes (PROM between 16+0/7–24+0/7 weeks) and oligohydramnios. Population: Follow up of infants of women who participated in the randomised controlled trial: PPROMEXIL-III (NTR3492). Methods: Surviving infants were invited for neurodevelopmental assessment up to 5 years of corrected age using a Bayley Scales of Infant and Toddler Development or a Wechsler Preschool and Primary Scale of Intelligence. Parents were asked to complete several questionnaires. Main outcome measures: Neurodevelopmental outcomes were measured. Mild delay was defined as −1 standard deviation (SD), severe delay as −2 SD. Healthy long-term survival was defined as survival without neurodevelopmental delay or respiratory problems. Results: In the amnioinfusion group, 18/28 children (64%) died versus 21/28 (75%) in the no intervention group (relative risk 0.86; 95% confidence interval [CI] 0.60–1.22). Follow-up data were obtained from 14/17 (82%) children (10 amnioinfusion, 4 no intervention). In both groups, 2/28 (7.1%) had a mild neurodevelopmental delay. No severe delay was seen. Healthy long-term survival occurred in 5/28 children (17.9%) after amnioinfusion versus 2/28 (7.1%) after no intervention (odds ratio 2.50; 95% CI 0.53–11.83). When analysing data for all assessed survivors, 10/14 (71.4%) survived without mild neurodevelopmental delay and 7/14 (50%) were classified healthy long-term survivor. Conclusions: In this small sample of women suffering second-trimester PROM and oligohydramnios, amnioinfusion did not improve long-term outcomes. Overall, 71% of survivors had no neurodevelopmental delay. Tweetable abstract: Healthy long-term survival was comparable for children born after second-trimester PROM and treatment with amnioinfusion or no intervention

    Predicting successful intended vaginal delivery after previous caesarean section: external validation of two predictive models in a Dutch nationwide registration-based cohort with a high intended vaginal delivery rate

    No full text
    Item does not contain fulltextOBJECTIVE: To externally validate two models from the USA (entry-to-care [ETC] and close-to-delivery [CTD]) that predict successful intended vaginal birth after caesarean (VBAC) for the Dutch population. DESIGN: A nationwide registration-based cohort study. SETTING: Seventeen hospitals in the Netherlands. POPULATION: Seven hundred and sixty-three pregnant women, each with one previous caesarean section and a viable singleton cephalic pregnancy without a contraindication for an intended VBAC. METHODS: The ETC model comprises the variables maternal age, prepregnancy body mass index (BMI), ethnicity, previous vaginal delivery, previous VBAC and previous nonprogressive labour. The CTD model replaces prepregnancy BMI with third-trimester BMI and adds estimated gestational age at delivery, hypertensive disease of pregnancy, cervical examination and induction of labour. We included consecutive medical records of eligible women who delivered in 2010. For validation, individual probabilities of women who had an intended VBAC were calculated. MAIN OUTCOME MEASURES: Discriminative performance was assessed with the area under the curve (AUC) of the receiver operating characteristic and predictive performance was assessed with calibration plots and the Hosmer-Lemeshow (H-L) statistic. RESULTS: Five hundred and fifteen (67%) of the 763 women had an intended VBAC; 72% of these (371) had an actual VBAC. The AUCs of the ETC and CTD models were 68% (95% CI 63-72%) and 72% (95% CI 67-76%), respectively. The H-L statistic showed a P-value of 0.167 for the ETC model and P = 0.356 for the CTD model, indicating no lack of fit. CONCLUSION: External validation of two predictive models developed in the USA revealed an adequate performance within the Dutch population
    corecore