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Design Case (design + case)
Terms modified by Design Case Selected AbstractsFetal heart rate patterns and ECG ST segment changes preceding metabolic acidaemia at birthBJOG : AN INTERNATIONAL JOURNAL OF OBSTETRICS & GYNAECOLOGY, Issue 2 2005Isis Amer-Wåhlin Objectives To compare the rates of abnormal ST segment patterns of the ECG and cardiotocographic (CTG) abnormalities in fetuses with metabolic acidaemia at birth and controls. To evaluate the inter-observer agreement in interpretation of ST analysis and CTG. Design Case,control study. Setting Three University hospitals in southern Sweden. Population Cases and controls were selected from the Swedish randomised controlled trial on intrapartum monitoring, including 4966 fetuses monitored with a scalp electrode. Methods Two obstetricians independently assessed the CTG and ST traces of 41 fetuses with metabolic acidaemia at birth and 101 controls, blinded to group, outcome and all clinical data. They classified each CTG trace and ST analysis as abnormal or not abnormal, and whether there was indication to intervene according to the CTG or to the CTG + ST guidelines. If their classification differed, assessment by a third obstetrician determined the final classification. Main outcome measures Rates of CTG and ST abnormalities and decisions to intervene. Rates of inter-observer agreement. Results CTG was classified as abnormal in 50% and ST in 63% of cases with acidaemia, and in 20% and 34% of controls, respectively. CTG abnormalities were judged to be indication for intervention in 45% and CTG + ST abnormalities in 56% of cases with acidaemia, and in 15% and 8% of controls, respectively. The proportion of agreement between the two initial observers was significantly higher for ST abnormalities (94%) than for CTG abnormalities (73%), and for indication to intervene according to CTG + ST (89%) than according to CTG alone (76%). Conclusions The inter-observer agreement rate was higher for a decision to intervene based on CTG + ST than on CTG alone. [source] Obstetric risk factors and persistent increases in brain parenchymal echogenicity in preterm infantsBJOG : AN INTERNATIONAL JOURNAL OF OBSTETRICS & GYNAECOLOGY, Issue 9 2004Arsenio Spinillo Objective To assess the risk of persistent (>7 days) increases in brain parenchymal echogenicity in preterm infants and their association with known obstetric risk factors. Design Case,control study of prospectively collected data. Setting A University hospital in Northern Italy. Population Eighty-five singleton infants between 24 and 34 weeks of gestation with a cranial ultrasonographic diagnosis of persistently increased parenchymal echogenicity without development of cystic degeneration, and 170 control infants with negative cranial ultrasonographic findings. Methods A comparison of the prevalence of selected obstetric risk factors between infants with persistent echo-dense lesions and negative controls. Main outcome measures Odds ratios of persistent echo-dense lesions including first-degree interactions between variables. Results After adjusting for birthweight, logistic regression analysis showed that the only factor associated with an increased risk of persistent brain echo-dense lesions in infants was multiple courses of antenatal steroids (OR = 2.14, 95% CI = 1.11,4.15, P= 0.024). In this group, the risk of persistent echo-dense lesions was particularly high in: (i) mothers receiving dexamethasone rather than betamethasone (P value for interaction = 0.015) and (ii) after expectant management of pre-eclampsia or intrauterine growth retardation (P value for interaction = 0.03). Conclusions Multiple doses of antenatal steroids, especially dexamethasone, could influence the prevalence of persistent increases in brain parenchymal echogenicity in preterm infants. [source] The tension-free vaginal tape in older womenBJOG : AN INTERNATIONAL JOURNAL OF OBSTETRICS & GYNAECOLOGY, Issue 8 2004Emmanuel Karantanis Objective To evaluate peri-operative morbidity, continence outcome and patient satisfaction in older women (,65 years) compared with younger women undergoing tension-free vaginal tape. Design Case controlled study. Setting Tertiary Urogynaecology Unit. Sample Women undergoing tension-free vaginal tape for urodynamic stress incontinence between July 1999 and July 2002 were included. Those with detrusor overactivity, voiding difficulty at urodynamics or requiring concomitant prolapse surgery were excluded. Methods Older women were case matched to a younger cohort for BMI, parity, mode of anaesthesia and whether it was a primary or secondary continence procedure. Main outcome measures Operative morbidity and continence outcome were assessed at six weeks. After a minimum six months follow up, patient satisfaction and continence outcome were assessed using the Genitourinary Treatment Satisfaction Score (GUTSS). Results The median hospital stay was one day and overall urinary tract infection rate was similar in both groups. Post-operative voiding difficulty rates were 3% in older versus 15% in younger women (P= 0.09). At six weeks, 65% of older versus 79% of younger women were dry (P= 0.2). At a median of 12 months, 15 (45%) of older versus 24 (73%) of younger women had no urinary symptoms (P= 0.05). Median GUTSS scores for satisfaction with continence outcome were lower for older 90% compared with 100% in younger women (P= 0.003). Conclusions Tension-free vaginal tape is an effective continence intervention in older women but has a lower continence satisfaction rate compared with younger women. [source] The complex relationship between smoking in pregnancy and very preterm deliveryBJOG : AN INTERNATIONAL JOURNAL OF OBSTETRICS & GYNAECOLOGY, Issue 3 2004Results of the Epipage study Objective To assess the relationship between cigarette smoking during pregnancy and very preterm births, according to the main mechanisms of preterm birth. Design Case,control study (the French Epipage study). Setting Regionally defined population of births in France. Population Eight hundred and sixty-four very preterm live-born singletons (between 27 and 32 completed weeks of gestation) and 567 unmatched full-term controls. Methods Data from the French Epipage study were analysed using a polytomous logistic regression model to control for social and demographic characteristics, pre-pregnancy body mass index and obstetric history. The main mechanisms of preterm delivery were classified as gestational hypertension, antepartum haemorrhage, premature rupture of membranes, spontaneous preterm labour and other miscellaneous mechanisms. Main outcome measures Odds ratios for very preterm birth for low to moderate (1,9 cigarettes/day) and heavy (,10 cigarettes/day) maternal smoking in pregnancy, estimated according to the main mechanisms leading to preterm birth. Results Smokers were more likely to give birth to very preterm infants than non-smokers [adjusted odds ratio (aOR) 1.7, 95% confidence interval (CI) 1.3,2.2]. Heavy smoking significantly reduced the risk of very preterm birth due to gestational hypertension (aOR 0.5, 95% CI 0.3,1.0), whereas both low to moderate and heavy smoking increased the risk of very preterm birth due to all other mechanisms (aOR between 1.6 and 2.8). Conclusion These data from the Epipage study show that maternal smoking during pregnancy is a risk factor for very preterm birth. The impact of maternal smoking on very preterm birth appears to be complex: it lowers the risk of very preterm birth due to gestational hypertension, but increases the risk of very preterm birth due to other mechanisms. These findings might explain why maternal smoking is more closely related to preterm birth among multiparous women than among nulliparous women. [source] Endothelial cell expression of adhesion molecules is induced by fetal plasma from pregnancies with umbilical placental vascular diseaseBJOG : AN INTERNATIONAL JOURNAL OF OBSTETRICS & GYNAECOLOGY, Issue 7 2002Xin Wang Objective To test the hypothesis that local production with spill into the fetal circulation of factor(s) injurious to endothelium is responsible for the vascular pathology present when the umbilical artery Doppler study is abnormal. Expression of adhesion molecules is a feature of endothelial cell activation. Design Case,control study. Setting University teaching hospital. Samples Fetal plasma was collected from 27 normal pregnancies, 39 pregnancies with umbilical placental vascular disease defined by abnormal umbilical artery Doppler and 11 pregnancies with pre-eclampsia and normal umbilical artery Doppler. Methods Isolated and cultured human umbilical vein endothelial cells from normal pregnancies were incubated with fetal plasma from three study groups. mRNA expression of intercellular cell adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1) and platelet-endothelial cell adhesion molecule-1 (PECAM-1) were assessed by reverse transcription-polymerase chain reaction. To confirm the occurrence of this in vivo, we measured the levels of soluble fractions of sICAM-1, sVCAM-1 and sPECAM-1 in the fetal circulation in the fetal plasma used for endothelial cell incubation. Results The mRNA expression of ICAM-1 [median 1.1 (interquartile range 0.5,1.9) vs 0.7 (0.3,1.2), P < 0.05] and PECAM-1 [2.1 (1.2,3.0) vs 1.5 (0.7,2.1), P < 0.05] was significantly higher following incubation with fetal plasma from umbilical placental vascular disease compared with the normal group. There was no difference in the expression of VCAM-1 [1.2 (0.9,1.8) vs 1.1 (0.8,1.6), ns]. The group with maternal pre-eclampsia and normal umbilical artery Doppler did not differ from the normal group. In the umbilical placental vascular disease group, the results were similar in the presence or absence of pre-eclampsia. For soluble fractions of the adhesion molecules released into the fetal circulation, we found the levels (ng/mL) of sICAM-1 [median 248.5 (interquartile range 197.3,315.7) vs 174.2 (144.5,212.9), P < 0.05] and sPECAM-1 [9.3 (6.2,11.1) vs 6.1 (5.4,7.7), P < 0.05] in fetal plasma to be significantly increased in the presence of umbilical placental vascular disease compared with the normal. Conclusions Vascular disease in the fetal umbilical placental circulation is associated with an elevation in mRNA expression by endothelial cells of ICAM-1 and PECAM-1. Our study provides evidence for endothelial cell activation and dysfunction in umbilical placental vascular disease. We speculate that the plasma factor(s) affecting the vessels of the umbilical villous tree is locally released by the trophoblast. The occurrence of the maternal syndrome of pre-eclampsia appears to be independent of this. [source] High incidence of obstetric interventions after successful external cephalic versionBJOG : AN INTERNATIONAL JOURNAL OF OBSTETRICS & GYNAECOLOGY, Issue 6 2002Louis Yik-Si Chan Objective To investigate the delivery outcome after successful external cephalic version (ECV). Design Case,control study. Setting University teaching hospital. Population The study group consisted of 279 consecutive singleton deliveries at term over a six-year period, all of which had had successful ECV performed. The control group included 28,447 singleton term deliveries during the same six-year period. Methods Between group differences were compared with the Mann,Whitney U test or Student's t test where appropriate. Odds ratio and 95% confidence interval (CI) were calculated for categorical variables. Main outcome measures Incidence of and indications for obstetric interventions. Results The risk of instrumental delivery and emergency caesarean section was higher in the ECV group (14.3%vs 12.8%; OR 1.4; 95% CI 1.0,2.0, and 23.3%vs 9.4%; OR 3.1; 95% CI 2.3,4.1, respectively). The higher caesarean rate was due to an increase in all major indications, namely, suspected fetal distress, failure to progress in labour and failed induction. The higher incidence of instrumental delivery was mainly due to an increase in prolonged second stage. The odds ratio for operative delivery remained significant after controlling for potential confounding variables. There were also significantly greater frequencies of labour induction (24.0%vs 13.4%; OR 2.0; 95% CI 1.5,2.7) and use of epidural analgesia (20.4%vs 12.4%; OR 1.8; 95% CI 1.4,2.4) by women in the ECV group. The higher induction rate is mainly due to induction for post term, abnormal cardiotocography (CTG) and antepartum haemorrhage (APH) of unknown origin. Conclusion The incidence of operative delivery and other obstetric interventions are higher in pregnancies after successful ECV. Women undergoing ECV should be informed about this higher risk of interventions. [source] Path-generation of articulated mechanisms by shape and topology variations in non-linear truss representationINTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING, Issue 12 2005A. Kawamoto Abstract This paper presents studies on an optimization-based method for path-generation of articulated mechanisms. An extended truss ground-structure approach is taken in which both the shape and topology of the truss are designed using cross-sectional areas and nodal positions as design variables. This leads to a technique for simultaneous type and dimensional synthesis of articulated mechanisms. For the analysis part it is essential to control the mechanism configuration so that the mechanism remains within a given configuration space, thus stabilizing the optimization process and resulting in realistic solutions. This can be achieved by using the Levenberg,Marquardt method. The design method is illustrated by a number of design cases for both closed and open input and output paths. Copyright © 2005 John Wiley & Sons, Ltd. [source] An assessment of hydraulic design of trickle laterals considering effect of minor losses,IRRIGATION AND DRAINAGE, Issue 4 2007Gürol Y canalisations d'eau; canalisations tertiaires; conception hydraulique; analyse; perte de charge Abstract The accurate design of trickle irrigation laterals needs to determine the total energy losses that includes the pipe friction losses along the lateral line and the local pressure losses, sometimes called minor losses, due to the protrusion of emitter barbs into the flow. Evaluation of energy losses is usually carried out by assuming the hypothesis that minor losses can be neglected, even if previous experimental studies indicated that minor losses can become a significant percentage of total energy losses as a consequence of the high number of emitters installed along the lateral line. In this study, a simple analytical procedure is presented to evaluate the effect of minor losses which is characterized by a coefficient ,i, expressing the amount of minor head losses as a fraction of the kinetic head, on trickle lateral design. According to both the design cases of without and including minor losses, the dimensionless design curves were developed for both the various lateral diameters and lengths. The results of two practical examples for designing either the diameter or the length indicated that, in some design cases, neglecting minor losses may lead to erroneous designs of the lateral diameter and length. This method is simple and easily adaptable to solve lateral hydraulic problems but sufficiently precise in comparison with the alternative procedures. The proposed equations are useful when applied for design and evaluation purposes and offer a practical field solution for laterals used in irrigation systems. Copyright © 2007 John Wiley & Sons, Ltd. La conception précise des canalisations tertiaires dans un système d'irrigation au goutte à goutte doit déterminer le total des pertes de charge qui viennent du frottement dans la canalisation elle-même mais aussi des pertes locales, parfois appelées pertes mineures, dues à la protubérance de barbes au niveau des goutteurs. Cette évaluation est normalement réalisée en considérant comme négligeables les pertes mineures, même si des études expérimentales ont montré que ces pertes mineures pouvaient constituer un pourcentage significatif de la perte de charge totale du fait du grand nombre de goutteurs installés le long de la canalisation tertiaire. Dans cette étude, une procédure analytique simple est proposée pour évaluer l'effet des pertes mineures sur la conception des canalisations tertiaires grâce à un coefficient ,i, exprimant le montant de ces pertes en une fraction de la charge cinétique. En fonction des diverses options de conception prenant ou non en compte les pertes mineures, des courbes de conception non dimensionnelles ont été tracées pour les diamètres et les longueurs des canalisations. Les résultats de deux exemples concrets montrent que, dans certains cas de conception, le fait de négliger les pertes mineures peut conduire à des conceptions de diamètre et de longueur erronées. Cette méthode est simple et facilement adaptable à la résolution de problèmes hydrauliques au niveau des tertiaires mais suffisamment précise par rapport des méthodes alternatives. Les équations proposées sont utiles pour la conception et l'évaluation et offrent une solution de terrain concrète pour les canalisations tertiaires utilisées dans des systèmes d'irrigation (au goutte à goutte). Copyright © 2007 John Wiley & Sons, Ltd. [source] Rotamer optimization for protein design through MAP estimation and problem-size reductionJOURNAL OF COMPUTATIONAL CHEMISTRY, Issue 12 2009Eun-Jong Hong Abstract The search for the global minimum energy conformation (GMEC) of protein side chains is an important computational challenge in protein structure prediction and design. Using rotamer models, the problem is formulated as a NP-hard optimization problem. Dead-end elimination (DEE) methods combined with systematic A* search (DEE/A*) has proven useful, but may not be strong enough as we attempt to solve protein design problems where a large number of similar rotamers is eligible and the network of interactions between residues is dense. In this work, we present an exact solution method, named BroMAP (branch-and-bound rotamer optimization using MAP estimation), for such protein design problems. The design goal of BroMAP is to be able to expand smaller search trees than conventional branch-and-bound methods while performing only a moderate amount of computation in each node, thereby reducing the total running time. To achieve that, BroMAP attempts reduction of the problem size within each node through DEE and elimination by lower bounds from approximate maximum-a-posteriori (MAP) estimation. The lower bounds are also exploited in branching and subproblem selection for fast discovery of strong upper bounds. Our computational results show that BroMAP tends to be faster than DEE/A* for large protein design cases. BroMAP also solved cases that were not solved by DEE/A* within the maximum allowed time, and did not incur significant disadvantage for cases where DEE/A* performed well. Therefore, BroMAP is particularly applicable to large protein design problems where DEE/A* struggles and can also substitute for DEE/A* in general GMEC search. © 2009 Wiley Periodicals, Inc. J Comput Chem, 2009 [source] | ||||||||||