Design of a large span-distributed load flying-wing cargo airplane with laminar flow control

A design study was conducted to add laminar flow control to a previously design span-distributed load airplane while maintaining constant range and payload. With laminar flow control applied to 100 percent of the wing and vertical tail chords, the empty weight increased by 4.2 percent, the drag decreased by 27.4 percent, the required engine thrust decreased by 14.8 percent, and the fuel consumption decreased by 21.8 percent. When laminar flow control was applied to a lesser extent of the chord (approximately 80 percent), the empty weight increased by 3.4 percent, the drag decreased by 20.0 percent, the required engine thrust decreased by 13.0 percent, and the fuel consumption decreased by 16.2 percent. In both cases the required take-off gross weight of the aircraft was less than the original turbulent aircraft

Preliminary design characteristics of a subsonic business jet concept employing laminar flow control

Aircraft configurations were developed with laminar flow control (LFC) and without LFC. The LFC configuration had approximately eleven percent less parasite drag and a seven percent increase in the maximum lift-to drag ratio. Although these aerodynamic advantages were partially offset by the additional weight of the LFC system, the LFC aircraft burned from six to eight percent less fuel for comparable missions. For the trans-atlantic design mission with the gross weight fixed, the LFC configuration would carry a greater payload for ten percent fuel per passenger mile

Effectiveness and costs of implementation strategies to reduce acid suppressive drug prescriptions: a systematic review

<p>Abstract</p> <p>Background</p> <p>Evaluation of evidence for the effectiveness of implementation strategies aimed at reducing prescriptions for the use of acid suppressive drugs (ASD).</p> <p>Methods</p> <p>A systematic review of intervention studies with a design according to research quality criteria and outcomes related to the effect of reduction of ASD medication retrieved from Medline, Embase and the Cochrane Library. Outcome measures were the strategy of intervention, quality of methodology and results of treatment to differences of ASD prescriptions and costs.</p> <p>Results</p> <p>The intervention varied from a single passive method to multiple active interactions with GPs. Reports of study quality had shortcomings on subjects of data-analysis. Not all outcomes were calculated but if so rction of prescriptions varied from 8% up to 40% and the cost effectiveness was in some cases negative and in others positive. Few studies demonstrated good effects from the interventions to reduce ASD.</p> <p>Conclusion</p> <p>Poor quality of some studies is limiting the evidence for effective interventions. Also it is difficult to compare cost-effectiveness between studies. However, RCT studies demonstrate that active interventions are required to reduce ASD volume. Larger multi-intervention studies are necessary to evaluate the most successful intervention instruments.</p

Dependency of magnetocardiographically determined fetal cardiac time intervals on gestational age, gender and postnatal biometrics in healthy pregnancies

BACKGROUND: Magnetocardiography enables the precise determination of fetal cardiac time intervals (CTI) as early as the second trimester of pregnancy. It has been shown that fetal CTI change in course of gestation. The aim of this work was to investigate the dependency of fetal CTI on gestational age, gender and postnatal biometric data in a substantial sample of subjects during normal pregnancy. METHODS: A total of 230 fetal magnetocardiograms were obtained in 47 healthy fetuses between the 15(th )and 42(nd )week of gestation. In each recording, after subtraction of the maternal cardiac artifact and the identification of fetal beats, fetal PQRST courses were signal averaged. On the basis of therein detected wave onsets and ends, the following CTI were determined: P wave, PR interval, PQ interval, QRS complex, ST segment, T wave, QT and QTc interval. Using regression analysis, the dependency of the CTI were examined with respect to gestational age, gender and postnatal biometric data. RESULTS: Atrioventricular conduction and ventricular depolarization times could be determined dependably whereas the T wave was often difficult to detect. Linear and nonlinear regression analysis established strong dependency on age for the P wave and QRS complex (r(2 )= 0.67, p < 0.001 and r(2 )= 0.66, p < 0.001) as well as an identifiable trend for the PR and PQ intervals (r(2 )= 0.21, p < 0.001 and r(2 )= 0.13, p < 0.001). Gender differences were found only for the QRS complex from the 31(st )week onward (p < 0.05). The influence on the P wave or QRS complex of biometric data, collected in a subgroup in whom recordings were available within 1 week of birth, did not display statistical significance. CONCLUSION: We conclude that 1) from approximately the 18(th )week to term, fetal CTI which quantify depolarization times can be reliably determined using magnetocardiography, 2) the P wave and QRS complex duration show a high dependency on age which to a large part reflects fetal growth and 3) fetal gender plays a role in QRS complex duration in the third trimester. Fetal development is thus in part reflected in the CTI and may be useful in the identification of intrauterine growth retardation

Management of irritable bowel syndrome in primary care: feasibility randomised controlled trial of mebeverine, methylcellulose, placebo and a patient self-management cognitive behavioural therapy website (MIBS trial)

Background: IBS affects 10-22% of the UK population. Abdominal pain, bloating and altered bowel habit affectquality of life, social functioning and time off work. Current GP treatment relies on a positive diagnosis, reassurance,lifestyle advice and drug therapies, but many suffer ongoing symptoms. A recent Cochrane review highlighted the lack of research evidence for IBS drugs. Neither GPs, nor patients have good evidence to inform prescribing decisions. However, IBS drugs are widely used: In 2005 the NHS costs were nearly £10 million for mebeverine and over £8 million for fibre-based bulking agents. CBT and self-management can be helpful, but poor availability in the NHS restricts their use. We have developed a web-based CBT selfmanagement programme, Regul8, based on an existing evidence based self-management manual and in partnership with patients. This could increase access with minimal increased costs.Methods/Design: The aim is to undertake a feasibility factorial RCT to assess the effectiveness of the commonlyprescribed medications in UK general practice for IBS: mebeverine (anti-spasmodic) and methylcellulose(bulkingagent)and Regul8, the CBT based self-management website. 135 patients aged 16 to 60 years with IBS symptoms fulfilling Rome III criteria, recruited via GP practices, will be randomised to 1 of 3 levels of the drug condition: mebeverine, methylcellulose or placebo for 6 weeks and to 1 of 3 levels of the website condition, Regul8 with a nurse telephone session and email support, Regul8 with minimalemail support, or no website, thus creating 9 groups.Outcomes: Irritable bowel symptom severity scale and IBS-QOL will be measured at baseline, 6 and 12 weeks asthe primary outcomes. An intention to treat analysis will be undertaken by ANCOVA for a factorial trial.Discussion: This pilot will provide valuable information for a larger trial. Determining the effectiveness ofcommonly used drug treatments will help patients and doctors make informed treatment decisions regarding drugmanagement of IBS symptoms, enabling better targeting of treatment. A web-based self-management CBT programme for IBS developed in partnership with patients has the potential to benefit large numbers of patients with low cost to the NHS. Assessment of the amount of email or therapist support required for the website willenable economic analysis to be undertaken.Trial Registration: ClinicalTrials.gov Identifier (NCT number): NCT00934973

The FAST-EU trial: 12-month clinical outcomes of women after intrauterine sonography-guided transcervical radiofrequency ablation of uterine fibroids: Gynecological Surgery

The FAST-EU Trial was designed to establish the effectiveness and confirm the safety of transcervical intrauterine sonography-guided radiofrequency ablation with the VizAblate (TM) System in the treatment of symptomatic uterine fibroids. This was a multicenter, prospective, single-arm trial involving academic and community hospitals in the United Kingdom, the Netherlands, and Mexico. Women with qualifying uterine fibroids and heavy menstrual bleeding underwent intrauterine sonography-guided transcervical radiofrequency ablation (RFA) with the VizAblate System; anesthesia was individualized. Patients were required to have up to five fibroids from 1 to 5 cm in diameter. The primary trial endpoint was the percentage change in perfused fibroid volume, as assessed by contrast-enhanced MRI at 3 months by an independent core laboratory. Secondary endpoints, evaluated at 6 and 12 months, included safety, percentage reductions in the Menstrual Pictogram (MP) score, and the Symptom Severity Score (SSS) subscale of the Uterine Fibroid Symptom-Quality of Life (UFS-QOL) questionnaire, along with the rate of surgical reintervention for abnormal uterine bleeding and the mean number of days to return to normal activity. Additional assessments included the Health-Related Quality of Life (HRQOL) subscale of the UFS-QOL, nonsurgical reintervention for abnormal uterine bleeding, anesthesia regimen, patient satisfaction, and pain during the recovery period. An additional MRI study was performed at 12 months on a subgroup of patients. Fifty patients (89 fibroids) underwent transcervical radiofrequency ablation with the VizAblate System. At 3 and 12 months, perfused fibroid volumes were reduced from baseline by an average of 68.1 +/- 28.6 and 67.4 +/- 31.9 %, respectively, while total fibroid volumes were reduced from baseline by an average of 54.7 +/- 37.4 and 66.6 +/- 32.1 %, respectively (all P <.001 compared with baseline; Wilcoxon signed-rank test). At 12 months, mean MP score and SSS decreased by 53.8 +/- 50.5 and 55.1 +/- 41.0 %, respectively; the mean HRQOL score increased by 277 +/- 483 %. There were four surgical reinterventions (8 %) within 12 months. This is the first report of the 12-month follow-up for patients in the FAST-EU Trial. In concert with previously reported 3- and 6-month endpoint data, the 12-month results of the FAST-EU Trial suggest that in addition to substantially reducing the perfused and total volume of targeted uterine fibroids, the VizAblate System is safe and effective through 12 months in providing relief of abnormal uterine bleeding associated with submucous, intramural, and transmural fibroids

Correlation of Reductions in Perfused Fibroid Volume With Subsequent Reductions in Total Fibroid Volume After Transcervical Radiofrequency Ablation

Study Objective To determine if the extent of fibroid ablation, as reflected in a decrease in perfused fibroid volume three months after treatment, correlates with a reduction in total fibroid volume at 12 months. Design Prospective, longitudinal, multicenter, single-arm trial. Setting Academic and community hospitals in the United Kingdom, The Netherlands and Mexico. Patients 27 women with heavy menstrual bleeding secondary to fibroids. Intervention Radiofrequency ablation guided by built-in intrauterine sonography (the Sonata™ System). Measurements and Main Results The 27 patients had a total of 42 fibroids that were ablated. Contrast-enhanced MRI was used to determine the perfused and total fibroid volumes at baseline, at 3 months post-treatment and again at 12 months post-treatment. All MRI measurements were performed at a single core laboratory (MedQIA, Los Angeles, USA). Using a least squares method for linear regression, the change in total fibroid volume at 12 months as a function of the change in perfused fibroid volume at 3 months was found to have a correlation coefficient (R2) of 0.7518. The linear equation describing this relationship was y = 0.9919x + 0.0052. Conclusion There is a positive correlation between the reduction in perfused fibroid volume noted on contrast-enhanced MRI at 3 months after transcervical radiofrequency ablation and the reduction in total fibroid volume at 12 months. Thus, as larger portions of a fibroid are ablated, there will tend to be a greater reduction in total fibroid volume at 1 year

Correlation of Reductions in Perfused Fibroid Volume With Subsequent Reductions in Total Fibroid Volume After Transcervical Radiofrequency Ablation

Study Objective To determine if the extent of fibroid ablation, as reflected in a decrease in perfused fibroid volume three months after treatment, correlates with a reduction in total fibroid volume at 12 months. Design Prospective, longitudinal, multicenter, single-arm trial. Setting Academic and community hospitals in the United Kingdom, The Netherlands and Mexico. Patients 27 women with heavy menstrual bleeding secondary to fibroids. Intervention Radiofrequency ablation guided by built-in intrauterine sonography (the Sonata™ System). Measurements and Main Results The 27 patients had a total of 42 fibroids that were ablated. Contrast-enhanced MRI was used to determine the perfused and total fibroid volumes at baseline, at 3 months post-treatment and again at 12 months post-treatment. All MRI measurements were performed at a single core laboratory (MedQIA, Los Angeles, USA). Using a least squares method for linear regression, the change in total fibroid volume at 12 months as a function of the change in perfused fibroid volume at 3 months was found to have a correlation coefficient (R2) of 0.7518. The linear equation describing this relationship was y = 0.9919x + 0.0052. Conclusion There is a positive correlation between the reduction in perfused fibroid volume noted on contrast-enhanced MRI at 3 months after transcervical radiofrequency ablation and the reduction in total fibroid volume at 12 months. Thus, as larger portions of a fibroid are ablated, there will tend to be a greater reduction in total fibroid volume at 1 year