3,300 research outputs found
A "MINLP" Formulation for Optimal Design of a Catalytic Distillation Column Based on a Generic Non Equilibrium Model
This contribution proposes a Mixed Integer Non Linear Programming (MINLP) formulation for optimal design of a catalytic distillation column based on a generic nonequilibrium model (NEQ). The solution strategy for the global optimization combines Simulated Annealing (SA) and Sequential Quadratic Programming (SQP) in order to
minimize the objective function. The solution of this MINLP problem yields the optimal values for the temperature, composition and flow rate profiles, tray geometry, column
diameter, reflux ratio, reboiler duty, feed tray location, number of trays and catalytic stage location. Hydraulic constraints (entrainment flooding, down-flow flooding,
weeping-dumpling) are also considered. For the example, the production of ETBE (Ethyl tert-butyl ether) is presented here
Hepatocellular carcinoma: Review of disease and tumor biomarkers.
© The Author(s) 2016.Hepatocellular carcinoma (HCC) is a common malignancy and now the second commonest global cause of cancer death. HCC tumorigenesis is relatively silent and patients experience late symptomatic presentation. As the option for curative treatments is limited to early stage cancers, diagnosis in non-symptomatic individuals is crucial. International guidelines advise regular surveillance of high-risk populations but the current tools lack sufficient sensitivity for early stage tumors on the background of a cirrhotic nodular liver. A number of novel biomarkers have now been suggested in the literature, which may reinforce the current surveillance methods. In addition, recent metabonomic and proteomic discoveries have established specific metabolite expressions in HCC, according to Warburgs phenomenon of altered energy metabolism. With clinical validation, a simple and non-invasive test from the serum or urine may be performed to diagnose HCC, particularly benefiting low resource regions where the burden of HCC is highest
Retrospective evaluation of a local protocol used to enhance laboratory savings through minimizing the performance of alkaline phosphatase isoenzyme analysis
Background: Alkaline phosphatase isoenzyme analysis is an expensive and time-consuming laboratory test. We evaluated the effect of a locally derived screening algorithm for alkaline phosphatase isoenzyme requests on the number of alkaline phosphatase isoenzyme analyses performed, laboratory cost and patient care. Method: A total of 110 alkaline phosphatase isoenzyme analysis requests from the year 2015 were reviewed and subsequent alkaline phosphatase concentrations were monitored over a two-year period, to determine if the decision of performing/not performing alkaline phosphatase isoenzyme analysis, based on the algorithm, had an impact on patient care and laboratory cost. All alkaline phosphatase isoenzyme analysis requests with two consecutive elevated alkaline phosphatase concentrations (>upper limit of reference interval) were screened and, subject to the gamma glutamyl transferase being within the reference interval, either Bone alkaline phosphatase or 25 hydroxyvitamin D was measured depending on the age of the patient. Results: Compliance with this algorithm led to the normalization of subsequent serum alkaline phosphatase in 97% of patients without requiring alkaline phosphatase isoenzyme analysis. The cost of performing Bone alkaline phosphatase and 25 hydroxyvitamin D in-house was £778.50, while the cost of performing alkaline phosphatase isoenzyme analysis would have been £3040. This resulted in a laboratory saving of £2261.50. Conclusions: Implementation of this algorithm led to a significant reduction in alkaline phosphatase isoenzyme analysis, without compromising patient care. Total savings could be increased if 25 hydroxyvitamin D was used as a first-line test, for all patients with an elevated alkaline phosphatase and a normal gamma glutamyl transferase regardless of age. This algorithm is cost-effective and can be implemented in laboratories with 25 hydroxyvitamin D assay
5G Radio Access Network Architecture for Terrestrial Broadcast Services
The 3rd Generation Partnership Project (3GPP) has defined based on the Long
Term Evolution (LTE) enhanced Multicast Broadcast Multimedia Service (eMBMS) a
set of new features to support the distribution of Terrestrial Broadcast
services in Release 14. On the other hand, a new 5th Generation (5G) system
architecture and radio access technology, 5G New Radio (NR), are being
standardised from Release 15 onwards, which so far have only focused on unicast
connectivity. This may change in Release 17 given a new Work Item set to
specify basic Radio Access Network (RAN) functionalities for the provision of
multicast/broadcast communications for NR. This work initially excludes some of
the functionalities originally supported for Terrestrial Broadcast services
under LTE e.g. free to air, receive-only mode, large-area single frequency
networks, etc. This paper proposes an enhanced Next Generation RAN architecture
based on 3GPP Release 15 with a series of architectural and functional
enhancements, to support an efficient, flexible and dynamic selection between
unicast and multicast/broadcast transmission modes and also the delivery of
Terrestrial Broadcast services. The paper elaborates on the Cloud-RAN based
architecture and proposes new concepts such as the RAN Broadcast/Multicast
Areas that allows a more flexible deployment in comparison to eMBMS. High-level
assessment methodologies including complexity analysis and inspection are used
to evaluate the feasibility of the proposed architecture design and compare it
with the 3GPP architectural requirements.Comment: 12 pages, 10 figures, 2 tables, IEEE Trans. Broadcastin
Physical Layer Performance Evaluation of LTE-Advanced Pro Broadcast and ATSC 3.0 Systems
This work provides a detailed performance analysis of the physical layer of two state-of-the-art point-to-multipoint (PTM) technologies: evolved Multimedia Broadcast Multicast Services (eMBMS) and Advanced Television Systems Committee - Third Generation (ATSC 3.0). The performance of these technologies is evaluated and compared using link-level simulations, considering relevant identified scenarios. A selection of Key Performance Indicators (KPI) for the International Mobile Telecommunications 2020 (IMT-2020) evaluation process has been considered. Representative use cases are also aligned to the test environments as defined in the IMT-2020 evaluation guidelines. It is observed that ATSC 3.0 outperforms both eMBMS solutions, i.e. MBMS over Single Frequency Networks (MBSFN) and Single-Cell PTM (SC-PTM) in terms of spectral efficiency, peak data rate and mobility, among others. This performance evaluation serves as a benchmark for comparison with a potential 5G PTM solution
Hepatocellular Carcinoma, Polymyositis, Rhabdomyolysis, and Acute Renal Failure
A 55 yr-old man presented with progressive muscle weakness and oliguria for 5days. Laboratory findings suggested rhabdomyolysis complicated with acute renal failure. A diagnosis of polymyositis was based upon the proximal muscle weakness on both upper and lower limbs, elevated muscle enzyme levels, muscle biopsy findings and the needle electromyography findings. The muscle biopsy showed extensive muscle necrosis and calcification. Investigations for underlying malignancy demonstrated hepatocellular carcinoma. The patient was managed with hemodialysis and high dose prednisolone. His renal function was fully recovered and his muscle power did improve slightly, but he died of a rupture of the hepatic tumor. In our view, this is an interesting case in that the hepatocellular carcinoma was associated with polymyositis and fulminant rhabdomyolysis-induced acute renal failure requiring hemodialysis
Wandering permanent pacemaker generators in children: a case series
<p>Abstract</p> <p>Introduction</p> <p>Epicardial permanent pacemaker generators are implanted some times in the abdominal wall in pediatric age groups.</p> <p>Case presentation</p> <p>Three permanent epicardial pacemakers that migrated in an unusual manner producing intraabdominal complications are reported.</p> <p>Conclusion</p> <p>The different clinical presentations of pacemaker migration in the pediatric age groups are highlighted and a few suggestions are made for avoiding such a complication.</p
Porous hydrogels from shark skin collagen crosslinked under dense carbon dioxide atmosphere
The possibility to fabricate marine collagen porous structures crosslinked with genipin under
high pressure carbon dioxide is investigated. Collagen from shark skin is used to prepare prescaffolds
by freeze-drying. The poor stability of the structures and low mechanical properties
require crosslinking of the structures. Under dense CO2 atmosphere, crosslinking of collagen
pre-scaffolds is allowed for 16 h. Additionally, the hydrogels are foamed and the scaffolds
obtained present a highly porous structure. In vitro cell culture tests performed with a
chondrocyte-like cell line show good cell
adherence and proliferation, which is a
strong indication of the potential of
these scaffolds to be used in tissue
cartilage tissue engineering.The research leading to these results has received funding from the European Union Seventh Framework Programme (FP7/2007-2013) under grant agreement no. KBBE-2010-266033 (project SPECIAL) and from FEDER through POCTEP Project 0330_IBEROMARE_1_P. Portuguese Foundation for Science and Technology is also gratefully acknowledged for post-doc grants of J. Moreira-Silva and T.H. Silva
Us and Them: Experimental evidence on what creates efficiency in choices made by married couples.
A recurring and puzzling pattern with experiments on intra-household behaviour is the common failure of couples to attain the cooperative solution. Using married couples from a low income area of Bogota, Colombia we conduct an experiment that raises the salience of the family vis-Ã -vis outsiders. In this experiment husbands and wives play a repeated voluntary contribution game. At the same time each participant plays an identical game with one stranger in the same session. When investments to the common pools are made from separate and non-fungible budgets, most subjects contribute more to the household pool than the stranger pool, but rarely contribute everything to the household even after repetition and opportunities for learning. Efficiency is not obtained. However, when subjects make contributions to the two games from a single budget many individuals converge rapidly on a strategy of investing everything in the household pool and contributing little to the pool with a stranger. Overall the amount invested in some pool rises. Our results are in line with games played with individuals in which in-group cooperation is higher when membership of the group is more salient. They suggest that strengthening family identity may raise intrahousehold cooperation, but at the expense of cooperation of interhousehold cooperation.JEL Classification Codes: C920, D130, D80http://www.grips.ac.jp/list/jp/facultyinfo/munro_alistair
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