271 research outputs found
Ethanol production from xylose by pichia stipitis NRRL Y-7124 in a stirred tank bioreactor
The ethanol production by Pichia stipitis was evaluated in a stirred tank bioreactor using semidefined medium containing xylose (90.0 g/l) as the main carbon source. Experimental assays were performed
according to a 22 full factorial design to evaluate the influence of aeration (0.25 to 0.75 vvm) and agitation (150 to 250 rpm) conditions on ethanol production. In the studied range of values, the agitation increase and aeration decrease favored ethanol production, which was maximum (26.7 g/l) using 250 rpm and 0.25 vvm,
conditions that gave a volumetric oxygen transfer coefficient (kLa value) of 4.9 h-1. Under these conditions, the ethanol yield factor, ethanol productivity, and the process efficiency were 0.32 g/g, 0.32 g/l.h, and 63%, respectively. These results are promising and contribute to the development of a suitable process for ethanol
production from xylose by Pichia stipitis.The authors gratefully acknowledge Santander, Fapesp, Capes, and CNPq (Brazil)
Transfer of thawed frozen embryo versus fresh embryo to improve the healthy baby rate in women undergoing IVF : the E-Freeze RCT
Peer reviewedPublisher PD
Optimal functional outcome measures for assessing treatment for Dupuytren's disease: A systematic review and recommendations for future practice
This article is available through the Brunel Open Access Publishing Fund. Copyright © 2013 Ball et al.; licensee BioMed Central Ltd.Background: Dupuytren's disease of the hand is a common condition affecting the palmar fascia, resulting in progressive flexion deformities of the digits and hence limitation of hand function. The optimal treatment remains unclear as outcomes studies have used a variety of measures for assessment. Methods: A literature search was performed for all publications describing surgical treatment, percutaneous needle aponeurotomy or collagenase injection for primary or recurrent Dupuytren’s disease where outcomes had been monitored using functional measures. Results: Ninety-one studies met the inclusion criteria. Twenty-two studies reported outcomes using patient reported outcome measures (PROMs) ranging from validated questionnaires to self-reported measures for return to work and self-rated disability. The Disability of Arm, Shoulder and Hand (DASH) score was the most utilised patient-reported function measure (n=11). Patient satisfaction was reported by eighteen studies but no single method was used consistently. Range of movement was the most frequent physical measure and was reported in all 91 studies. However, the methods of measurement and reporting varied, with seventeen different techniques being used. Other physical measures included grip and pinch strength and sensibility, again with variations in measurement protocols. The mean follow-up time ranged from 2 weeks to 17 years. Conclusions: There is little consistency in the reporting of outcomes for interventions in patients with Dupuytren’s disease, making it impossible to compare the efficacy of different treatment modalities. Although there are limitations to the existing generic patient reported outcomes measures, a combination of these together with a disease-specific questionnaire, and physical measures of active and passive individual joint Range of movement (ROM), grip and sensibility using standardised protocols should be used for future outcomes studies. As Dupuytren’s disease tends to recur following treatment as well as extend to involve other areas of the hand, follow-up times should be standardised and designed to capture both short and long term outcomes
ExoClock Project III: 450 new exoplanet ephemerides from ground and space observations
The ExoClock project has been created with the aim of increasing the
efficiency of the Ariel mission. It will achieve this by continuously
monitoring and updating the ephemerides of Ariel candidates over an extended
period, in order to produce a consistent catalogue of reliable and precise
ephemerides. This work presents a homogenous catalogue of updated ephemerides
for 450 planets, generated by the integration of 18000 data points from
multiple sources. These sources include observations from ground-based
telescopes (ExoClock network and ETD), mid-time values from the literature and
light-curves from space telescopes (Kepler/K2 and TESS). With all the above, we
manage to collect observations for half of the post-discovery years (median),
with data that have a median uncertainty less than one minute. In comparison
with literature, the ephemerides generated by the project are more precise and
less biased. More than 40\% of the initial literature ephemerides had to be
updated to reach the goals of the project, as they were either of low precision
or drifting. Moreover, the integrated approach of the project enables both the
monitoring of the majority of the Ariel candidates (95\%), and also the
identification of missing data. The dedicated ExoClock network effectively
supports this task by contributing additional observations when a gap in the
data is identified. These results highlight the need for continuous monitoring
to increase the observing coverage of the candidate planets. Finally, the
extended observing coverage of planets allows us to detect trends (TTVs -
Transit Timing Variations) for a sample of 19 planets. All products, data, and
codes used in this work are open and accessible to the wider scientific
community.Comment: Recommended for publication to ApJS (reviewer's comments
implemented). Main body: 13 pages, total: 77 pages, 7 figures, 7 tables. Data
available at http://doi.org/10.17605/OSF.IO/P298
Comparison of total parathyroidectomy without autotransplantation and without thymectomy versus total parathyroidectomy with autotransplantation and with thymectomy for secondary hyperparathyroidism: TOPAR PILOT-Trial
<p>Abstract</p> <p>Background</p> <p>Secondary hyperparathyroidism (sHPT) is common in patients with chronic renal failure. Despite the initiation of new therapeutic agents, several patients will require parathyroidectomy (PTX). Total PTX with autotransplantation of parathyroid tissue (TPTX+AT) and subtotal parathyroidectomy (SPTX) are currently considered as standard surgical procedures in the treatment of sHPT. Recurrencerates after TPTX+AT or SPTX are between 10% and 12% (median follow up: 36 months).</p> <p>Recent retrospective studies demonstrated a lower rate of recurrent sHPT of 0–4% after PTX without autotransplantation and thymectomy (TPTX) with no higher morbidity when compared to the standard procedures. The observed superiority of TPTX is flawed due to different definitions of outcomes, varying follow up periods and different surgical treatment strategies (with and without thymectomy).</p> <p>Methods/Design</p> <p>Patients with sHPT (intact parathyroid hormone > 10 times above the upper limit of normal) on long term dialysis (>12 months) will be randomized either to TPTX or TPTX+AT and followed for 36 months. Outcome parameters are recurrence rates of sHPT, frequencies of reoperations due to refractory hypoparathyroidism or recurrent/persistent hyperparathyroidism, postoperative morbidity and mortality and quality of life. 50 patients per group will be randomized in order to obtain relevant frequencies of outcome parameters that will form the basis for a large scale confirmatory multicentred randomized controlled trial.</p> <p>Discussion</p> <p>sHPT is a disease with a high incidence in patients with chronic renal failure. Even a small difference in outcomes will be of clinical relevance. To assess sufficient data about the rate of recurrent sHPT after both methods, a multicentred, randomized controlled trial (MRCT) under standardized conditions is mandatory.</p> <p>Due to the existing uncertainties the calculated number of patients necessary in each treatment arm (n > 4000) makes it impossible to perform this study as a confirmatory trial. Therefore estimates of different outcomes are performed using a pilot MRCT comparing 50 versus 50 randomized patients in order to establish a hypothesis that can be tested thereafter.</p> <p>If TPTX proves to have a lower rate of recurrent sHPT, no relevant disadvantages and no higher morbidity than TPTX+AT, current surgical practice may be changed.</p> <p>Trial registration</p> <p>International Standard Randomized Controlled Trial Number Registration (ISRCTN86202793)</p
State of nature 2023
This is the fourth State of Nature Report. It provides a comprehensive overview of species trends across the UK, including specific assessments for England, Northern Ireland, Scotland and Wales, and for the UK’s Overseas Territories
A next generation, pilot-scale continuous sterilization system for fermentation media
A new continuous sterilization system was designed, constructed, started up, and qualified for media sterilization for secondary metabolite cultivations, bioconversions, and enzyme production. An existing Honeywell Total Distributed Control 3000-based control system was extended using redundant High performance Process Manager controllers for 98 I/O (input/output) points. This new equipment was retrofitted into an industrial research fermentation pilot plant, designed and constructed in the early 1980s. Design strategies of this new continuous sterilizer system and the expanded control system are described and compared with the literature (including dairy and bio-waste inactivation applications) and the weaknesses of the prior installation for expected effectiveness. In addition, the reasoning behind selection of some of these improved features has been incorporated. Examples of enhancements adopted include sanitary heat exchanger (HEX) design, incorporation of a “flash” cooling HEX, on-line calculation of F(o) and R(o), and use of field I/O modules located near the vessel to permit low-cost addition of new instrumentation. Sterilizer performance also was characterized over the expected range of operating conditions. Differences between design and observed temperature, pressure, and other profiles were quantified and investigated
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