708 research outputs found
Analysis of biopharma raw materials by electrophoresis microchips with contactless conductivity detection
Detailed information concerning the composition of the raw materials employed in the production of biologics is important for the efficient control and optimization of bioprocesses. We demonstrate the application of electrophoresis microchips with capacitively-coupled contactless conductivity detection (C4D) to the analysis of wa-ter-soluble vitamins and metal cations in raw material solutions that are subse-quently fed into bioreactors for the production of biologics
Monolithic centrifugal microfluidic platform for bacteria capture and concentration, lysis, nucleic-acid amplification, and real-time detection
We report the design, fabrication, and characterization of a polymer centrifugal microfluidic system for the specific detection of bacterial pathogens. This single-cartridge platform integrates bacteria capture and concentration, supernatant solution removal, lysis, and nucleic-acid sequence-based amplification (NASBA) in a single unit. The unit is fabricated using multilayer lamination and consists of five different polymer layers. Bacteria capture and concentration are accomplished by sedimentation in five minutes. Centrifugation forces also drive the subsequent steps. A wax valve is integrated in the cartridge to enable high-speed centrifugation. Oil is used to prevent evaporation during reactions requiring thermal cycling. Device functionality was demonstrated by real-time detection of E. coli from a 200-muL sample
Liquid recirculation in microfluidic channels by the interplay of capillary and centrifugal forces
We demonstrate a technique to recirculate liquids in a microfluidic device, maintaining a thin fluid layer such that typical diffusion times for analytes to reach the device surface are < 1 min. Fluids can be recirculated at least 1000 times across the same surface region, with no change other than slight evaporation, by alternating the predominance of centrifugal and capillary forces. Mounted on a rotational platform, the device consists of two hydrophilic layers separated by a thin pressure-sensitive adhesive (PSA) layer that defines the microfluidic structure. We demonstrate rapid, effective fluid mixing with this device
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Visual analytics of flight trajectories for uncovering decision making strategies
In air traffic management and control, movement data describing actual and planned flights are used for planning, monitoring and post-operation analysis purposes with the goal of increased efficient utilization of air space capacities (in terms of delay reduction or flight efficiency), without compromising the safety of passengers and cargo, nor timeliness of flights. From flight data, it is possible to extract valuable information concerning preferences and decision making of airlines (e.g. route choice) and air traffic managers and controllers (e.g. flight rerouting or optimizing flight times), features whose understanding is intended as a key driver for bringing operational performance benefits. In this paper, we propose a suite of visual analytics techniques for supporting assessment of flight data quality and data analysis workflows centred on revealing decision making preferences
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Clustering Trajectories by Relevant Parts for Air Traffic Analysis
Clustering of trajectories of moving objects by similarity is an important technique in movement analysis. Existing distance functions assess the similarity between trajectories based on properties of the trajectory points or segments. The properties may include the spatial positions, times, and thematic attributes. There may be a need to focus the analysis on certain parts of trajectories, i.e., points and segments that have particular properties. According to the analysis focus, the analyst may need to cluster trajectories by similarity of their relevant parts only. Throughout the analysis process, the focus may change, and different parts of trajectories may become relevant. We propose an analytical workflow in which interactive filtering tools are used to attach relevance flags to elements of trajectories, clustering is done using a distance function that ignores irrelevant elements, and the resulting clusters are summarized for further analysis. We demonstrate how this workflow can be useful for different analysis tasks in three case studies with real data from the domain of air traffic. We propose a suite of generic techniques and visualization guidelines to support movement data analysis by means of relevance-aware trajectory clustering
Effects of Planetary Wave-breaking on the Seasonal Variation of Total Column Ozone
The effects of planetary wave breaking on the seasonal variation of total column ozone are investigated using a zonally averaged chemical-radiative-transport model of the atmosphere. The planetary wave breaking effects of zonal wavenumbers k=1 and k=2 are significant in the middle latitude stratosphere during Northern Hemisphere (NH) winter, whereas only wave k=1 is important during Southern Hemisphere (SH) winter. The mixing and induced meridional circulation due to the planetary wave breaking increases the seasonal variation of total column ozone in NH (SH) middle latitudes by âŒ20% (âŒ10%)
Ganglion intraneural del nervio cubital: presentaciĂłn de un caso
Se presenta un caso de un Tumor del Nervio Cubital que suele conocerse en
la literatura como Ganglion Intraneural o Quiste mucoide de los nervios, y que es capaz de
producir parĂĄlisis sensitiva y nerviosa. Se intenta diferenciarlos de los Gangliones sinoviales
a travĂ©s de un estudio de la bibliografĂa de todas las Ă©pocas, considerĂĄndose que se trata de
degeneraciones del tejido conjuntivo nervioso que conducen a la metaplasia del tejido de sostén
endo y perineural con vacuolizaciĂłn de los fibroblastos y producciĂłn de sustancia mucoide.
En la revisiĂłn bibliogrĂĄfica realizada no se encuentran mĂĄs de una decena de casos con
localizaciĂłn en el miembro superior y en el nervio cubital. Se esbozan los criterios de diagnĂłstico
diferencial con otras minoraciones y lesiones de los nervios y se indica como tratamiento
recomendable la exĂ©resis quirĂșrgica.A case of Ganglion Mucoid Cyst of the Ulnar Nerve producing combined motor
and sensory deficit is reported. Inthe bibliographic study is possible to do the differential diagnosis
between this specific tumor and the common Ganglia of the tendon sheath. Its origine may
be the neural conjuntive tissue degeneration whit subsecuent endo and perineural tissue
metaplasia, fibroblastic cyst and production of mucoide substance. There are not more than
ten similar cases published in the literature. Its diferential diagnosis and recomended treatment
is presented
A 1024-sample serum analyzer chip for cancer diagnostics
We present a platform that combines microarrays and microfluidic techniques to measure four protein biomarkers in 1024 serum samples for a total of 4096 assays per device. Detection is based on a surface fluorescence sandwich immunoassay with a limit of detection of similar to 1 pM for most of the proteins measured: PSA, TNF-alpha, IL-1 beta, and IL-6. To validate the utility of our platform, we measured these four biomarkers in 20 clinical human serum samples, 10 from prostate cancer patients and 10 female and male controls. We compared the results of our platform to a conventional ELISA and found a good correlation between them. However, compared to a classical ELISA, our device reduces the total cost of reagents by 4 orders of magnitude while increasing throughput by 2 orders of magnitude. Overall, we demonstrate an integrated approach to perform low-cost and rapid quantification of protein biomarkers from over one thousand serum samples. This new high-throughput technology will have a significant impact on disease diagnosis and management
Geometrical dynamics of Born-Infeld objects
We present a geometrical inspired study of the dynamics of -branes. We
focus on the usual nonpolynomial Dirac-Born-Infeld action for the worldvolume
swept out by the brane in its evolution in general background spacetimes. We
emphasize the form of the resulting equations of motion which are quite simple
and resemble Newton's second law, complemented with a conservation law for a
worldvolume bicurrent. We take a closer look at the classical Hamiltonian
analysis which is supported by the ADM framework of general relativity. The
constraints and their algebra are identified as well as the geometrical role
they play in phase space. In order to illustrate our results, we review the
dynamics of a -brane immersed in a background spacetime.
We exhibit the mechanical properties of Born-Infeld objects paving the way to a
consistent quantum formulation.Comment: LaTex, 20 pages, no figure
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