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Abstract: Ca(1−x)Nd2x/3TiO3 microwave dielectric ceramics were prepared by the mixed oxide route; powders were calcined at 1100°C and sintered at 1450–1500°C. High density, single phase products were obtained for all compositions. Grain sizes ranged from 1μm to 100μm. There was evidence of significant discontinuous grain growth in mid range compositions; all ceramics were characterised by complex domain structures. With increasing Nd content there was a evidence of a transition from an orthorhombic Pbnm structure to a monoclinic C2/m structure. This was accompanied by a decrease in relative permittivity (ɛ r) from 180 to 78, and decrease in the temperature coefficient of resonant frequency (τ f) from +770ppmK−1 to +200ppmK−1. The product of dielectric Q value and resonant frequency (Q × f) varied in a grossly non-systematic way, exhibiting a peak at 13,000GHz in Ca0.7Nd0.2TiO3. [Copyright &y& Elsevier]

Double perovskite Sr2FeMoO6 was prepared by two ways consisting in sol–gel technique and solid-state reaction method. The resulting powders from gel and mixed oxides precursors showed microstructures consisting of very fine grains (0.5–0.8μm) and a crystalline perovskite structure. The structural and microstructural properties of the double perovskite Sr2FeMoO6 powders as-prepared and ceramics were compared. Tetragonal Sr2FeMoO6 pellets were prepared from the two powders by spark plasma sintering at: 1000, 1100 and 1200°C and then annealing at 1200°C, 2h in 5%H2/Ar. The pellets presented different magnetic characteristics. The saturation magnetization of the samples prepared by sol–gel is close to those prepared by conventional synthesis method. [ABSTRACT FROM AUTHOR]

Objective Anal incontinence occurs as a result of damage to pelvic floor and the anal sphincter. In women, vaginal delivery has been recognized as the primary cause. To date, figures quoted for overt third degree anal sphincter tear vary between 0% and 26.9% of all vaginal deliveries and the prevalence of anal incontinence following primary repair vary between 15% and 61%. Our aim was to analyse the long-term (minimum 10 years post primary repair) anorectal function and quality of life in a cohort of women who suffered a third degree tear (Group 1) and compare the results with a cohort of women who underwent an uncomplicated vaginal delivery (Group 2) or an elective caesarean delivery (Group 3). Method In all, 107 patients who suffered a third degree tear between 1981 and 1993 were contacted with a validated questionnaire. The two control groups comprised of 125 patients in each category. Those who responded to the questionnaire were invited for anorectal physiology studies and endoanal ultrasound. Results Of the total number contacted, 54, 71 and 54 women from the three groups returned the completed questionnaire. In the three groups, a total of 28 (53%), 13 (19%) and six (11%) complained of anal incontinence ( P < 0.0001) respectively. Comparison of quality of life scores between the groups showed a poorer quality of life in those who suffered a tear ( P < 0.0001). In addition, in spite of primary repair, 13 (59%) patients in group 1 showed a persistent sphincter defect compared to one (4%) occult defect in Group 2 and none in Group 3. Conclusion Our study indicates that long-term results of primary repair are not encouraging. It therefore emphasizes the importance of primary prevention and preventing further sphincter damage in those who have already suffered an injury (during subsequent deliveries). [ABSTRACT FROM AUTHOR]

Laparoscopic Nissen fundoplication is an established treatment for gastroesophageal reflux disease (GERD). Postoperative improvement in esophageal physiology can be indicative of successful surgery, but the degree to which it correlates with symptom control remains questionable. We have performed this study to assess the utility of postoperative esophageal physiology studies in predicting long-term symptomatic outcome. Between August 1997 and August 2003, 145 patients with symptomatic GERD underwent laparoscopic Nissen fundoplication as part of a randomized trial. Four months after surgery patients were invited to have postoperative esophageal physiology studies. In November 2005, a postal questionnaire was sent to all patients in order to assess reflux symptomatology (DeMeester symptom score). Completed symptom questionnaires were returned by 108 patients (74%) after a median of 5.7 years postoperatively. Linear regression of manometry data showed a significant correlation between the level of postoperative neosphincter pressure either above or below the median and long-term scores for heartburn ( p = 0.03), dysphagia ( p = 0.02), regurgitation ( p = 0.01), and total symptom score ( p = 0.002). In contrast, there was no evidence of a significant correlation between results of postoperative esophageal pH studies and symptom scores. Postoperative physiology studies, particularly manometry, may be predictive of long-term symptoms following laparoscopic Nissen fundoplication. [ABSTRACT FROM AUTHOR]

Compares laparoscopic Nissen fundoplication (LNF) with proton-pump inhibitor (PPI) therapy in the treatment of gastro-oesophageal reflux disease (GORD). Randomization of patients with a history of GORD to receive LNF or PPI therapy; Performance of twenty-four-hour pH monitoring and manometry and quality of life assessment after treatment; Manifestation by the LNF group of significantly greater improvements in both gastrointestinal symptom and general well-being compared with the PPI group.

Assessment of the effect of balloon dilation of the lower esophageal sphincter in achalasia currently relies on symptom scores, radiologic studies, or manometry. We have used vector volume analysis which constructs a three-dimensional (3D) pressure profile to examine the effects of balloon dilation on the sphincter. Studies were performed in 26 normal subjects and in 11 patients with achalasia in whom vector volume was determined before and/or after balloon dilation. Vector volume analysis was performed using a multilumen manometry catheter with eight side-reading ports. The catheter was withdrawn through the sphincter using a continuous pull-through technique. A 3D pressure profile was constructed. Vector volume of the lower esophageal sphincter shows a marked radial and linear asymmetry in normal subjects. 3D pressure profiles showed a symmetrical increase in lower esophageal sphincter pressure in untreated achalasia. Mean vector volumes pre and postdilation fell from 254 to 88 cm[sup 3] respectively. This was associated with a fall in the mean radial symmetry index from 0.83 to 0.76. Improvement in dysphagia occurred in those patients in whom pressure fell to 15 mmHg or below in at least three adjacent segments. This technique may be a useful tool in the assessment of patients with achalasia and postdilation results may help to predict the long-term outcome of treatment. [ABSTRACT FROM AUTHOR]