33 resultados para Controlled short rate
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The clinical usefulness of hemodialysis catheters is limited by increased infectious morbidity and mortality. Topical antiseptic agents, such as mupirocin, are effective at reducing this risk but have been reported to select for antibiotic-resistant strains. The aim of the present study was to determine the efficacy and the safety of exit-site application of a standardized antibacterial honey versus mupirocin in preventing catheter-associated infections. A randomized, controlled trial was performed comparing the effect of thrice-weekly exit-site application of Medihoney versus mupirocin on infection rates in patients who were receiving hemodialysis via tunneled, cuffed central venous catheters. A total of 101 patients were enrolled. The incidences of catheter-associated bacteremias in honey-treated (n = 51) and mupirocin-treated (n = 50) patients were comparable (0.97 versus 0.85 episodes per 1000 catheter-days, respectively; NS). On Cox proportional hazards model analysis, the use of honey was not significantly associated with bacteremia-free survival (unadjusted hazard ratio, 0.94; 95% confidence interval, 0.27 to 3.24; P = 0.92). No exit-site infections occurred. During the study period, 2% of staphylococcal isolates within the hospital were mupirocin resistant. Thrice-weekly application of standardized antibacterial honey to hemodialysis catheter exit sites was safe, cheap, and effective and resulted in a comparable rate of catheter-associated infection to that obtained with mupirocin (although the study was not adequately powered to assess therapeutic equivalence). The effectiveness of honey against antibiotic-resistant microorganisms and its low likelihood of selecting for further resistant strains suggest that this agent may represent a satisfactory alternative means of chemoprophylaxis in patients with central venous catheters.
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Background Resection remains the best treatment for carcinoma of the oesophagus in terms of local control, but local recurrence and distant metastasis remain an issue after surgery. We aimed to assess whether a short preoperative chemoradiotherapy regimen improves outcomes for patients with resectable oesophageal cancer. Methods 128 patients were randomly assigned to surgery alone and 128 patients to surgery after 80 mg/m(2) cisplatin on day 1, 800 mg/m(2) fluorouracil on days 1-4, with concurrent radiotherapy of 35 Gy given in 15 fractions. The primary endpoint was progression-free survival. Secondary endpoints were overall survival, tumour response, toxic effects, patterns of failure, and quality of life. Analysis was done by intention to treat. Findings Neither progression-free survival nor overall survival differed between groups (hazard ratio [HR] 0.82 [95% CI 0.61-1.101 and 0.89 [0.67-1.19], respectively). The chemoradiotherapy-and-surgery group had more complete resections with clear margins than did the surgery-alone group (103 of 128 [80%] vs 76 of 128 [59%], p=0.0002), and had fewer positive lymph nodes (44 of 103 [43%] vs 69 of 103 [67%], p=0.003). Subgroup analysis showed that patients with squamous-cell tumours had better progression-free survival with chemoradiotherapy than did those with non-squamous tumours (HR 0.47 [0.25-0.86] vs 1.02 [0.72-1.44]). However, the trial was underpowered to determine the real magnitude of benefit in this subgroup. Interpretation Preoperative chemoradiotherapy with cisplatin and fluorouracil does not significantly improve progression-free or overall survival for patients with resectable oesophageal cancer compared with surgery alone. However, further assessment is warranted of the role of chemoradiotherapy in patients with squamouscell tumours.
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The RAFT-CLD-T methodology is demonstrated to be not only applicable to 1-substituted monomers such as styrene and acrylates, but also to 1,1-disubstituted monomers such as MMA. The chain length of the terminating macromolecules is controlled by CPDB in MMA bulk free radical polymerization at 80 degrees C. The evolution of the chain length dependent termination rate coefficient, k(t)(i,i), was constructed in a step-wise fashion, since the MMA/CPDB system displays hybrid behavior (between conventional and living free radical polymerization) resulting in initial high molecular weight polymers formed at low RAFT agent concentrations. The obtained CLD of k(t) in MMA polymerizations is compatible with the composite model for chain length dependent termination. For the initial chain-length regime, up to a degree of polymerization of 100, k(t) decreases with alpha (in the expression k(t)(i,i) = k(t)(0) . i(-alpha)) being close to 0.65 at 80 degrees C. At chain lengths exceeding 100, the decrease is less pronounced (affording an alpha of 0.15 at 80 degrees C). However, the data are best represented by a continuously decreasing nonlinear functionality implying a chain length dependent alpha.
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Purpose To evaluate the efficacy of a psychoeducational intervention in improving cancer-related fatigue. Patients and Methods This randomized controlled trial involved 109 women commencing adjuvant chemotherapy for stage I or II breast cancer in five chemotherapy treatment centers. Intervention group patients received an individualized fatigue education and support program delivered in the clinic and by phone over three 10- to 20-minute sessions 1 week apart. Instruments included a numeric rating scale assessing confidence with managing fatigue; 11-point numeric rating scales measuring fatigue at worst, average, and best; the Functional Assessment of Cancer Therapy-Fatigue and Piper Fatigue Scales; the Cancer Self-Efficacy Scale; the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire C30; and the Hospital Anxiety and Depression Scale. For each outcome, separate analyses of covariance of change scores between baseline (T1) and the three follow-up time points (T2, T3, and T4) were conducted, controlling for the variable's corresponding baseline value. Results Compared with the intervention group, mean difference scores between the baseline (T1) and immediate after the test (T2) assessments increased significantly more for the control group for worst and average fatigue, Functional Assessment of Cancer Therapy-Fatigue, and Piper fatigue severity and interference measures. These differences were not observed between baseline and T3 and T4 assessments. No significant differences were identified for any pre- or post-test change scores for confidence with managing fatigue, cancer self-efficacy, anxiety, depression, or quality of life. Conclusion Preparatory education and support has the potential to assist women to cope with cancer-related fatigue in the short term. However, further research is needed to identify ways to improve the potency and sustainability of psychoeducational interventions for managing cancer-related fatigue.
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The use of phenyldithioacetic acid (PDA) in homopolymerizations of styrene or methyl acrylate produced only a small fraction of chains with dithioester end groups. The polymerizations using 1-phenylentyl phenyldithioacetate (PEPDTA) and PDA in the same reaction showed that PDA had little or no influence on the rate or molecular weight distribution even when a 1:1 ratio is used. The mechanistic pathway for the polymerizations in the presence of PDA seemed to be different for each monomer. Styrene favors addition of styrene to PDA via a Markovnikov type addition to form a reactive RAFT agent. The polymer was shown by double detection SEC to contain dithioester end groups over the whole distribution. This polymer was then used in a chain extension experiment and the M-n was close to theory. A unique feature of this work was that PDA could be used to form a RAFT agent in situ by heating a mixture of styrene and PDA for 24 h at 70 degrees C and then polymerizing in the presence of AIBN to give a linear increase in Mn and low values of PDI (< 1.14). In the case of the polymerization of MA with PDA, the mechanism was proposed to be via degradative chain transfer. (c) 2005 Wiley Periodicals, Inc.
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Objective To compare the pubovaginal sling and transurethral Macroplastique in the treatment of female stress urinary incontinence (SUI) and intrinsic sphincter deficiency (ISD). Design A prospective randomised controlled trial comparing two surgical treatments for SUI and ISD. Setting Tertiary referral urogynaecology unit in Australia. Population Women with SUI and ISD who were suitable for either surgical technique. Methods Forty-five women with SUI and ISD were randomly allocated the pubovaginal sling (n = 22) or transurethral Macroplastique (n = 23). Subjective and objective success rates, patient satisfaction and cost measurements at six months and one year following surgery were the primary outcome measures. A telephone questionnaire survey was performed at a mean follow up period of 62 months (43-71). Main outcome measure Comparison of success rates, complications and costs. Results The symptomatic and patient satisfaction success rates were similar following the sling and Macroplastique with the objective success rate being significantly greater (P < 0.001) following the sling (81% vs 9%). Macroplastique had significantly lower morbidity but was more expensive than the sling (P < 0.001). Response rate at 62 months follow up was 60% in both groups with the sling group reporting better continence success (69% vs 21%) and satisfaction rates (69% vs 29%, P = 0.057). Conclusions The pubovaginal sling was more effective and economical than transurethral Macroplastique for the treatment of SUI and ISD. However, transurethral Macroplastique remains an appropriate treatment in selected cases of SUI and ISD.
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Hyaluronic acid is routinely produced through fermentation of both Group A and C streptococci. Despite significant production costs associated with short fermentations and removal of contaminating proteins released during entry into stationary phase, hyaluronic acid is typically produced in batch rather than continuous culture. The main reason is that hyaluronic acid synthesis has been found to be unstable in continuous culture except at very low dilution rates. Here, we investigated the mechanisms underlying this instability and developed a stable, high dilution rate (0.4 h(-1)) chemostat process for both chemically defined and complex media operating for more than 150 h of production. In chemically defined medium, the product yield was 25% higher in chemostat cultures than in conventional batch culture when arginine or glucose was the limiting substrate. In contrast, glutamine limitation resulted in higher ATP requirements and a yield similar to that observed in batch culture. In complex, glucose-limited medium, ATP requirements were greatly reduced but biomass synthesis was favored over hyaluronic acid and no improvement in hyaluronic acid yield was observed. The successful establishment of continuous culture at high dilution rate enables both commercial production at reduced cost and a more rational characterization and optimization of hyaluronic acid production in streptococci. (c) 2005 Wiley Periodicals, Inc.
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Background: The age-related loss of muscle power in older adults is greater than that of muscle strength and is associated with a decline in physical performance. Objective: To investigate the effects of a short-term high-velocity varied resistance training programme on physical performance in healthy community-dwelling adults aged 60-80 years. Methods: Subjects undertook exercise (EX; n = 15) or maintained customary activity (controls, CON; n = 10) for 8 weeks. The EX group trained 2 days/week using machine weights for three sets of eight repetitions at 35, 55, and 75% of their one-repetition maximum (the maximal weight that an individual can lift once with acceptable form) for seven upper- and lower-body exercises using explosive concentric movements. Results: Fourteen EX and 10 CON subjects completed the study. Dynamic muscle strength significantly increased (p = 0.001) in the EX group for all exercises (from 21.4 +/- 9.6 to 82.0 +/- 59.2%, mean +/- SD) following training, as did knee extension power (p < 0.01). Significant improvement occurred for the EX group in the floor rise to standing (10.4 &PLUSMN; 11.5%, p = 0.004), usual 6-metre walk (6.6 &PLUSMN; 8.2%, p = 0.010), repeated chair rise (10.4 &PLUSMN; 15.6%, p = 0.013), and lift and reach (25.6 &PLUSMN; 12.1%, p = 0.002) performance tasks but not in the CON group. Conclusions: Progressive resistance training that incorporates rapid rate-of-force development movements may be safely undertaken in healthy older adults and results in significant gains in muscle strength, muscle power, and physical performance. Such improvements could prolong functional independence and improve the quality of life. Copyright (C) 2005 S. Karger AG, Basel.
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To study the dynamics of protein recruitment to DNA lesions, ion beams can be used to generate extremely localized DNA damage within restricted regions of the nuclei. This inhomogeneous spatial distribution of lesions can be visualized indirectly and rapidly in the form of radiation-induced foci using immunocytochemical detection or GFP-tagged DNA repair proteins. To analyze faster protein translocations and a possible contribution of radiation-induced chromatin movement in DNA damage recognition in live cells, we developed a remote-controlled system to obtain high-resolution fluorescence images of living cells during ion irradiation with a frame rate of the order of seconds. Using scratch replication labeling, only minor chromatin movement at sites of ion traversal was observed within the first few minutes of impact. Furthermore, time-lapse images of the GFP-coupled DNA repair protein aprataxin revealed accumulations within seconds at sites of ion hits, indicating a very fast recruitment to damaged sites. Repositioning of the irradiated cells after fixation allowed the comparison of live cell observation with immunocytochemical staining and retrospective etching of ion tracks. These results demonstrate that heavy-ion radiation-induced changes in sub-nuclear structures can be used to determine the kinetics of early protein recruitment in living cells and that the changes are not dependent on large-scale chromatin movement at short times postirradiation. © 2005 by Radiation Research Society.
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Background: Methodological challenges such as recruitment problems and participant burden make clinical trials in palliative care difficult. In 2001-2004, two community-based randomized controlled trials (RCTs) of case conferences in palliative care settings were independently conducted in Australia-the Queensland Case Conferences trial (QCC) and the Palliative Care Trial (PCT). Design: A structured comparative study of the QCC and PCT was conducted, organized by known practical and organizational barriers to clinical trials in palliative care. Results: Differences in funding dictated study designs and recruitment success; PCT had 6 times the budget of QCC. Sample size attainment. Only PCT achieved the sample size goal. QCC focused on reducing attrition through gatekeeping while PCT maximized participation through detailed recruitment strategies and planned for significant attrition. Testing sustainable interventions. QCC achieved a higher percentage of planned case conferences; the QCC strategy required minimal extra work for clinicians while PCT superimposed conferences on normal work schedules. Minimizing participant burden. Differing strategies of data collection were implemented to reduce participant burden. QCC had short survey instruments. PCT incorporated all data collection into normal clinical nursing encounters. Other. Both studies had acceptable withdrawal rates. Intention-to-treat analyses are planned. Both studies included substudies to validate new outcome measures. Conclusions: Health service interventions in palliative care can be studied using RCTs. Detailed comparative information of strategies, successes and challenges can inform the design of future trials. Key lessons include adequate funding, recruitment focus, sustainable interventions, and mechanisms to minimize participant burden.
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Objectives: To re-examine interhospital variation in 30 day survival after acute myocardial infarction ( AMI) 10 years on to see whether the appointment of new cardiologists and their involvement in emergency care has improved outcome after AMI. Design: Retrospective cohort study. Setting: Acute hospitals in Scotland. Participants: 61 484 patients with a first AMI over two time periods: 1988 - 1991; and 1998 - 2001. Main outcome measures: 30 day survival. Results: Between 1988 and 1991, median 30 day survival was 79.2% ( interhospital range 72.1 - 85.1%). The difference between highest and lowest was 13.0 percentage points ( age and sex adjusted, 12.1 percentage points). Between 1998 and 2001, median survival rose to 81.6% ( and range decreased to 78.0 - 85.6%) with a difference of 7.6 ( adjusted 8.8) percentage points. Admission hospital was an independent predictor of outcome at 30 days during the two time periods ( p< 0.001). Over the period 1988 - 1991, the odds ratio for death ranged, between hospitals, from 0.71 ( 95% confidence interval ( CI) 0.58 to 0.88) to 1.50 ( 95% CI 1.19 to 1.89) and for the period 1998 - 2001 from 0.82 ( 95% CI 0.60 to 1.13) to 1.46 ( 95% CI 1.07 to 1.99). The adjusted risk of death was significantly higher than average in nine of 26 hospitals between 1988 and 1991 but in only two hospitals between 1998 and 2001. Conclusions: The average 30 day case fatality rate after admission with an AMI has fallen substantially over the past 10 years in Scotland. Between-hospital variation is also considerably less notable because of better survival in the previously poorly performing hospitals. This suggests that the greater involvement of cardiologists in the management of AMI has paid dividends.
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Background: Migraine is a distressing disorder that is often triggered by stress and poor sleep. Only one randomized controlled trial (RCT) has assessed the effects of massage therapy on migraine experiences, which yielded some promising findings. Purpose: An RCT was designed to replicate and extend the earlier findings using a larger sample, additional stress-related indicators, and assessments past the final session to identify longer-term effects of massage therapy on stress and migraine, experiences. Methods: Migraine sufferers (N = 47) who were randomly assigned to massage or control conditions completed daily assessments of migraine experiences and sleep patterns for 13 weeks. Massage participants attended weekly massage sessions during Weeks 5 to 10. State anxiety, heart rates, and salivary cortisol were assessed before and after the sessions. Perceived stress and coping efficacy were assessed at Weeks 4, 10, and 13. Results: Compared to control participants, massage participants exhibited greater improvements in migraine frequency and sleep quality during the intervention weeks and the 3 follow-up weeks. Trends for beneficial effects of massage therapy on perceived stress and coping efficacy were observed. During sessions, massage induced decreases in state anxiety, heart rate, and cortisol. Conclusions: The findings provide preliminary support for the utility of massage therapy as a nonpharmacologic treatment for individuals suffering from migraines.
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Increasing evidence is emerging that the performance of enhanced biological phosphorus removal (EBPR) systems relies on not only the total amount but also the composition of volatile fatty acids (VFAs). Domestic wastewater often contains limited amounts of VFAs with acetic acid typically being the dominating species. Consequently, prefermenters are often employed to generate additional VFAs to meet the demand for carbon by EBPR and/or denitrification processes. Limited knowledge is currently available on the effects of operational conditions on the production rate and composition of VFAs in prefermenters. In this study, a series of controlled batch experiments were conducted with sludge from a full-scale prefermenter to determine the impact of solids concentration, pH and addition of molasses on prefermentation processes. It was found that an increase in solids concentration enhanced total VFA production with an increased propionic acid fraction. The optimal pH for prefermentation was in the range of 6-7 with significant productivity loss when pH was below 5.5. Molasses addition significantly increased the production of VFAs particularly the propionic acid. However, the fermentation rate was likely limited by the biological activity of the sludge rather than by the amount of molasses added.
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Nodulation in legumes provides a major conduit of available nitrogen into the biosphere. The development of nitrogen-fixing nodules results from a symbiotic interaction between soil bacteria, commonly called rhizobia, and legume plants. Molecular genetic analysis in both model and agriculturally important legume species has resulted in the identification of a variety of genes that are essential for the establishment, maintenance and regulation of this symbiosis. Autoregulation of nodulation (AON) is a major internal process by which nodule numbers are controlled through prior nodulation events. Characterisation of AON-deficient mutants has revealed a novel systemic signal transduction pathway controlled by a receptor-like kinase. This review reports our present level of understanding on the short- and long-distance signalling networks controlling early nodulation events and AON.
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Background The use of sunscreens on the skin can prevent sunburn but whether long-term use can prevent skin cancer is not known. Also, there is evidence that oral betacarotene supplementation lowers skin-cancer rates in animals, but there is limited evidence of its effect in human beings. Methods In a community-based randomised trial with a 2 by 2 factorial design, individuals were assigned to four treatment groups: daily application of a sun protection factor 15-plus sunscreen to the head, neck, arms, and hands, and betacarotene supplementation (30 mg per day); sunscreen plus placebo tablets; betacarotene only; or placebo only. Participants were 1621 residents of Nambour in southeast Queensland, Australia. The endpoints after 4.5 years of follow-up were the incidence of basal-cell and squamous-cell carcinomas both in terms of people treated for newly diagnosed disease and in terms of the numbers of tumours that occurred. Analysis of the effect of sunscreen was based only on skin cancers that developed on sites of daily application. All analyses were by intention to treat. Findings 1383 participants underwent full shin examination by a dermatologist in the follow-up period. 250 of them developed 758 new skin cancers during the follow-up period. There were no significant differences in the incidence of first new shin cancers between groups randomly assigned daily sunscreen and no daily sunscreen (basal-cell carcinoma 2588 vs 2509 per 100 000; rate ratio 1.03 [95% CI 0.73-1.46]; squamous-cell carcinoma 876 vs 996 per 100 000; rate ratio 0.88 [0.50-1.56]). Similarly, there was no significant difference between the betacarotene and placebo groups in incidence of either cancer (basal-cell carcinoma 3954 vs 3806 per 100 000; 1.04 [0.73-1.27]; squamous-cell carcinoma 1508 vs 1146 per 100 000; 1.35 [0.84-2.19]). In terms of the number of tumours, there was no effect on incidence of basal-cell carcinoma by sunscreen use or by betacarotene but the incidence of squamous-cell carcinoma was significantly lower in the sunscreen group than in the no daily sunscreen group (1115 vs 1832 per 100 000; 0.61 [0.46-0.81]). Interpretation There was no harmful effect of daily use of sunscreen in this medium-term study. Cutaneous squamous-cell carcinoma, but not basal-cell carcinoma seems to be amenable to prevention through the routine use of sunscreen by adults for 4.5 years. There was no beneficial or harmful effect on the rates of either type of skin cancer, as a result of betacarotene supplementation.