362 research outputs found
Membrane Technology for the Recovery of Lignin: A Review
Citation: Humpert, D., Ebrahimi, M., & Czermak, P. (2016). Membrane Technology for the Recovery of Lignin: A Review. Membranes, 6(3), 13. doi:10.3390/membranes6030042Utilization of renewable resources is becoming increasingly important, and only sustainable processes that convert such resources into useful products can achieve environmentally beneficial economic growth. Wastewater from the pulp and paper industry is an unutilized resource offering the potential to recover valuable products such as lignin, pigments, and water [1]. The recovery of lignin is particularly important because it has many applications, and membrane technology has been investigated as the basis of innovative recovery solutions. The concentration of lignin can be increased from 62 to 285 g.L-1 using membranes and the recovered lignin is extremely pure. Membrane technology is also scalable and adaptable to different waste liquors from the pulp and paper industry
Mathematical modeling of diafiltration
The main objective of this study is to provide a general mathematical model in a compact form for batch diafiltration techniques. The presented mathematical framework gives a rich representation of diafiltration processes due to the employment of concentration-dependent solute rejections. It unifies the existing models for constant volume dilution mode, variable volume dilution mode, and concentration mode operations. The use of such a mathematical framework allows the optimization of the overall diafiltration process. The provided methodology is particularly applicable for decision makers to choose an appropriate diafiltration technique for the given separation design problem
Manufacturing Cells for Clinical Use
Citation: Weiss, M. L., Rao, M. S., Deans, R., & Czermak, P. (2016). Manufacturing Cells for Clinical Use. Stem Cells International, 5. doi:10.1155/2016/1750697The growth in the number of registered clinical trials indicates that there is a need for cells for many types of cell therapy. Figure 1, which is reprinted from the excellent blog maintained by Alexi Bersenev, shows that the cell type used in most clinical trials worldwide is the mesenchymal stromal cell (MSC). The MSC type requires in vitro expansion to reach a clinical dose and thus there is a desire to optimize and standardize processes and procedures for MSC manufacture specifically for clinical use
Application of deep learning-based image reconstruction in MR imaging of the shoulder joint to improve image quality and reduce scan time
OBJECTIVES
To compare the image quality and diagnostic performance of conventional motion-corrected periodically rotated overlapping parallel line with enhanced reconstruction (PROPELLER) MRI sequences with post-processed PROPELLER MRI sequences using deep learning-based (DL) reconstructions.
METHODS
In this prospective study of 30 patients, conventional (19 min 18 s) and accelerated MRI sequences (7 min 16 s) using the PROPELLER technique were acquired. Accelerated sequences were post-processed using DL. The image quality and diagnostic confidence were qualitatively assessed by 2 readers using a 5-point Likert scale. Analysis of the pathological findings of cartilage, rotator cuff tendons and muscles, glenoid labrum and subacromial bursa was performed. Inter-reader agreement was calculated using Cohen's kappa statistic. Quantitative evaluation of image quality was measured using the signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR).
RESULTS
Mean image quality and diagnostic confidence in evaluation of all shoulder structures were higher in DL sequences (p value = 0.01). Inter-reader agreement ranged between kappa values of 0.155 (assessment of the bursa) and 0.947 (assessment of the rotator cuff muscles). In 17 cases, thickening of the subacromial bursa of more than 2 mm was only visible in DL sequences. The pathologies of the other structures could be properly evaluated by conventional and DL sequences. Mean SNR (p value = 0.01) and CNR (p value = 0.02) were significantly higher for DL sequences.
CONCLUSIONS
The accelerated PROPELLER sequences with DL post-processing showed superior image quality and higher diagnostic confidence compared to the conventional PROPELLER sequences. Subacromial bursa can be thoroughly assessed in DL sequences, while the other structures of the shoulder joint can be assessed in conventional and DL sequences with a good agreement between sequences.
KEY POINTS
âą MRI of the shoulder requires long scan times and can be hampered by motion artifacts. âą Deep learning-based convolutional neural networks are used to reduce image noise and scan time while maintaining optimal image quality. The radial k-space acquisition technique (PROPELLER) can reduce the scan time and has potential to reduce motion artifacts. âą DL sequences show a higher diagnostic confidence than conventional sequences and therefore are preferred for assessment of the subacromial bursa, while conventional and DL sequences show comparable performance in the evaluation of the shoulder joint
Role of complement in in vitro and in vivo lung inflammatory reactions
Complement is one of the integral buttresses of the inflammatory response. In addition to host defense activities, proinflammatory properties of several complement components are described. This overview elucidates the role of complement in inflammatory reactions in vitro and in vivo, focusing on the complement activation products, C5a, and the membrane attack complex, C5bâ9. Using several approaches, the impact of these complement components in mechanisms relevant to neutrophil recruitment is emphasized. In addition, the participation of complement in endothelial superoxide generation and its essential requirement for full expression of lung injury is demonstrated, as are the involved intracellular signal transduction pathways. Understanding the mechanisms of complementâinduced proinflammatory effects may provide a basis for future therapeutic blockade of complement and/or its activation products. J. Leukoc. Biol. 64: 40â48; 1998.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/142061/1/jlb0040.pd
A rapid method for an offline glycerol determination during microbial fermentation
Background: The purpose of this work was to find a rapid method for
glycerol detection during microbial fermentations. The method
requirements were, first, to avoid sample pretreatment, and second, to
measure glycerol precisely especially out of fermentation broth.
Results: This was achieved by combining two reaction principles \u2014
the Malaprade reaction and the Hantzsch reaction. In the Malaprade
reaction, glycerol is converted into formaldehyde. This forms a dye in
the Hantzsch reaction after which adsorption is than detected. The
subsequent assay was investigated with two different fermentation
media, a chemically undefined and a chemically defined media, used for
Pichia pastoris fermentation. In both media, as well as in real
fermentation samples, glycerol content could be reproducibly detected
with the method. Moreover, measurements were more precise than using a
standard glycerol detection kit. Conclusions: With this rapid assay,
glycerol could be detected easily in microbial fermentation broth. It
is reliable over a wide concentration range including advantages such
as an easy assay set-up, a short assay time and no sample pretreatment
Regulatory effects of interleukinâ11 during acute lung inflammatory injury
The role of interleukinâ11 (ILâ11) was evaluated in the IgG immune complex model of acute lung injury in rats. ILâ11 mRNA and protein were both upâregulated during the course of this inflammatory response. Exogenously administered ILâ11 substantially reduced, in a doseâdependent manner, the intrapulmonary accumulation of neutrophils and the lung vascular leak of albumin. These in vivo antiâinflammatory effects of ILâ11 were associated with reduced NFâÎșB activation in lung, reduced levels of tumor necrosis factor α (TNFâα) in bronchoalveolar lavage (BAL) fluids, and diminished upâregulation of lung vascular ICAMâ1. It is interesting that ILâ11 did not affect BAL fluid content of the CXC chemokines, macrophage inflammatory proteinâ2 (MIPâ2) and cytokineâinducible neutrophil chemoattractant (CINC); the presence of ILâ11 did not affect these chemokines. However, BAL content of C5a was reduced by ILâ11. These data indicate that ILâ11 is a regulatory cytokine in the lung and that, like other members of this family, its antiâinflammatory properties appear to be linked to its suppression of NFâÎșB activation, diminished production of TNFâα, and reduced upâregulation of lung vascular ICAMâ1. J. Leukoc. Biol. 66: 151â157; 1999.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141937/1/jlb0151.pd
Membrane-assisted enzymatic production of galactosyl-oligosaccharides from lactose in a continuous process
Functional foods such as oligosaccharides have attained significant acceptance in Japan and are attracting interest elsewhere. Beneficial physiological properties are attributed to oligosaccharides. Here, we describe the continuous production of oligosaccharides from a low-cost substrate (lactose) in a continuous membrane-assisted reactor (both polymeric and inorganic membranes were tested). Different enzymes, a number of feed concentrations, and different
average residence times were investigated. The enzymes were used in their native form. Retention and recycling of the enzyme was successful, while the products together with some unreacted substrate and byproducts were removed as the ultrafiltration permeate. For the ultrafiltration, a steady-state flux of about 20 l/m2 hr was achieved. A maximum oligosaccharide concentration of over 40 %w/w was reached with an average residence time of 1 hr and a feed lactose concentration
of 31 %w/w. Pilot scale experiments based on the laboratory tests are also reported
Conformal TiO aerogel-like films by plasma deposition: from omniphobic antireflective coatings to perovskite solar cells photoelectrodes
The ability to control porosity in oxide thin films is one of the key factors
that determine their properties. Despite the abundance of dry processes for the
synthesis of oxide porous layers, the high porosity range is typically achieved
by spin-coating-based wet chemical methods. Besides, special techniques such as
supercritical drying are required to replace the pore liquid with air while
maintaining the porous network. In this study, we propose a new method for the
fabrication of ultra-porous titanium dioxide thin films at room or mild
temperatures (T lower or equal to 120 degrees Celsius) by the sequential
process involving plasma deposition and etching. These films are conformal to
the substrate topography even for high-aspect-ratio substrates and show
percolated porosity values above 85 percent that are comparable to advanced
aerogels. The films deposited at room temperature are amorphous. However, they
become partly crystalline at slightly higher temperatures presenting a
distribution of anatase clusters embedded in the sponge-like structure.
Surprisingly, the porous structure remains after annealing the films at 450
degrees Celsius in air, which increases the fraction of the embedded anatase
nanocrystals. The films are antireflective, omniphobic, and photoactive
becoming super-hydrophilic subjected to UV light irradiation The supported
percolated nanoporous structure can be used as an electron-conducting electrode
in perovskite solar cells. The properties of the cells depend on the aerogel
film thickness reaching efficiencies close to those of commercial mesoporous
anatase electrodes. This generic solvent-free synthesis is scalable and is
applicable to ultra-high porous conformal oxides of different compositions with
potential applications in photonics, optoelectronics, energy storage, and
controlled wetting.Comment: 31 pages, 10 Figs. plus Supporting Information 7 pags, 6 figs. Full
Pape
Silicon detector for a Compton Camera in Nuclear Medical Imaging
Electronically collimated gamma ca\-me\-ras based on Com\-pton scattering in silicon pad sensors may improve imaging in nuclear medicine and bio-medical research. The work described here concentrates on the silicon pad detector developed for a prototype Compton camera. The silicon pad sensors are read out using low noise VLSI CMOS chips and novel fast triggering chips. Depending on the application a light weight and dense packaging of sensors and its readout electronics on a hybrid is required. We describe the silicon pad sensor and their readout with the newly designed hybrid. %The silicon detector of a Compton camera %may contain up to ~analogue channels requiring %a fast and low cost data acquisition system. We also describe a modular and low-cost data acquisition system (CCDAQ) based on a digital signal processor which is interfaced to the EPP port of personal computers. Using the CCDAQ and the hybrids energy spectra of gamma-ray photons from technetium (Tc) and americium (Am) were acquired with an energy resolution of 2.45~keV FWHM for the 140.5~keV photo-absorption line of Tc. For all pads the discrimination threshold in the trigger chip was between (15 and 25)~keV
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