One step flow-through adsorptive purification of tubulin from tissue homogenate

2005 ◽  
Vol 818 (1) ◽  
pp. 83-87 ◽  
Author(s):  
Annamma Anil ◽  
Reena Pandit ◽  
Madhavi Indap ◽  
Arvind Lali
Keyword(s):  
Tissue Homogenate ◽  
Step Flow ◽  
One Step ◽  
Flow Through

scholarly journals Monolithic integration of nanorod arrays on microfluidic chips for fast and sensitive one-step immunoassays

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Ye Wang ◽  
Jiongdong Zhao ◽  
Yu Zhu ◽  
Shurong Dong ◽  
Yang Liu ◽  
...  
Keyword(s):  
Troponin I ◽  
Specific Antigen ◽  
Monolithic Integration ◽  
Detection Sensitivity ◽  
Quantitative Detection ◽  
Plasmonic Nanostructures ◽  
Nanorod Arrays ◽  
Microfluidic Chips ◽  
One Step ◽  
Flow Through

AbstractHere, we present integrated nanorod arrays on microfluidic chips for fast and sensitive flow-through immunoassays of physiologically relevant macromolecules. Dense arrays of Au nanorods are easily fabricated through one-step oblique angle deposition, which eliminates the requirement of advanced lithography methods. We report the utility of this plasmonic structure to improve the detection limit of the cardiac troponin I (cTnI) assay by over 6 × 105-fold, reaching down to 33.9 fg mL−1 (~1.4 fM), compared with an identical assay on glass substrates. Through monolithic integration with microfluidic elements, the device enables a flow-through assay for quantitative detection of cTnI in the serum with a detection sensitivity of 6.9 pg mL−1 (~0.3 pM) in <6 min, which was 4000 times lower than conventional glass devices. This ultrasensitive detection arises from the large surface area for antibody conjugation and metal-enhanced fluorescent signals through plasmonic nanostructures. Moreover, due to the parallel arrangement of flow paths, simultaneous detection of multiple cancer biomarkers, including prostate-specific antigen and carcinoembryonic antigen, has been fulfilled with increased signal-to-background ratios. Given the high performance of this assay, together with its simple fabrication process that is compatible with standard mass manufacturing techniques, we expect that the prepared integrated nanorod device can bring on-site point-of-care diagnosis closer to reality.

Direct freezing of whole blood enables analysis of leucocyte markers by flow cytometry: a proof-of-concept study

2021 ◽  
Author(s):  
Pénélope Bourgoin ◽  
Inès Ait Belkacem ◽  
Isabelle Arnoux ◽  
Pierre-Emmanuel Morange ◽  
Fabrice Malergue
Keyword(s):  
Flow Cytometry ◽  
Whole Blood ◽  
Blood Cells ◽  
White Blood Cells ◽  
Proof Of Concept ◽  
Fresh Blood ◽  
Blood Samples ◽  
Step Flow ◽  
Freezing Method ◽  
One Step

Aim: A new one-step flow cytometry procedure has been recently demonstrated for identifying subjects with infections, but only for fresh whole blood samples. The goal of this study was to assess its applicability on frozen samples, by proposing a new method to perform the sample freezing directly and easily. Methods: Fresh blood was tested, then frozen either directly or with dimethylsulfoxide and serum. Common markers of white blood cells as well as infection-related biomarkers were tested. Results: All percentages of leucocyte subsets and levels of infection-related biomarkers were significantly correlated between frozen and fresh samples. Conclusion: The direct freezing method enables an accurate assessment of common cellular sub-populations and of levels of important infectious biomarkers via flow cytometry.

Deterministic Tree Networks for River Drainage Basins

Fractals ◽  
1998 ◽  
Vol 06 (03) ◽  
pp. 245-261 ◽  
Author(s):  
M. R. Errera ◽  
A. Bejan
Keyword(s):  
Porous Medium ◽  
Flow Resistance ◽  
Drainage Basin ◽  
Drainage Basins ◽  
River Drainage ◽  
One Step ◽  
Local Properties ◽  
Flow Through ◽  
Internal Properties ◽  
Flow Medium

This paper shows that the dendritic patterns formed by low-resistance channels in a river drainage basin are reproducible and can be deduced from a single principle that acts at every step in the development of the pattern: the constrained minimization of global resistance in area-to-point flow. The river basin is modeled as a two-dimensional territory with Darcy flow through a saturated heterogeneous porous medium with uniform flow addition per unit area. From one step to the next, small elements of the porous medium are dislodged and removed in ways that minimize the global flow resistance. The removed elements are replaced by channels with lower flow resistance. The channels form a dendritic pattern that is deterministic, not random. The finest details of this structure are sensitive to internal properties and external forcing, i.e. variations in the local properties of the flow medium, and the manner in which the total area-to-point flow rate varies as the structure develops. Remarkably insensitive to such effects are the basic type and rough size of the flow structure (channels versus no channels, dendrite, number of branches) and the minimized global resistance to flow.

scholarly journals One Step, Two Step, Network Step? Complementary Perspectives on Communication Flows in Twittered Citizen Protests

2016 ◽  
Vol 35 (4) ◽  
pp. 444-461 ◽  
Author(s):  
Martin Hilbert ◽  
Javier Vásquez ◽  
Daniel Halpern ◽  
Sebastián Valenzuela ◽  
Eduardo Arriagada
Keyword(s):  
Social Media ◽  
Flow Model ◽  
Network Flows ◽  
Global Network ◽  
Digital Platforms ◽  
Step Flow ◽  
Fine Grained ◽  
Total Communication ◽  
One Step ◽  
Communication Flow

The article analyzes the nature of communication flows during social conflicts via the digital platform Twitter. We gathered over 150,000 tweets from citizen protests for nine environmental social movements in Chile and used a mixed methods approach to show that long-standing paradigms for social mobilization and participation are neither replicated nor replaced but reshaped. In digital platforms, long-standing communication theories, like the 1955 two-step flow model, are still valid, while direct one-step flows and more complex network flows are also present. For example, we show that it is no contradiction that social media participants mainly refer to intermediating amplifiers of communicated messages (39% of the mentions from participants go through this two-step communication flow), while at the same time, traditional media outlets and official protest voices receive 80–90% of their mentions directly through a direct one-step flow from the same participants. While nonintuitive at first sight, Bayes’s theorem allows to detangle the different perspectives on the arising communication channel. We identify the strategic importance of a group of amplifying intermediaries in local positions of the networks, who coexist with specialized voices and professional media outlets at the center of the global network. We also show that direct personalized messages represent merely 20% of the total communication. This shows that the fine-grained digital footprint from social media enables us to go beyond simplistic views of a single all-encompassing step flow model for social communication. The resulting research agenda builds on long-standing theories with a new set of tools.

Improving cardio-thoracic patient flow through the ICU: One step at a time

2018 ◽  
Vol 31 (2) ◽  
pp. 128-129
Author(s):  
K. Fairclough ◽  
M. Bedford ◽  
H. Davies
Keyword(s):  
Patient Flow ◽  
One Step ◽  
Flow Through

The One-Step Flow of Communication

2006 ◽  
Vol 608 (1) ◽  
pp. 213-232 ◽  
Author(s):  
W. Lance Bennett ◽  
Jarol B. Manheim
Keyword(s):  
Step Flow ◽  
One Step ◽  
The One

scholarly journals One and Two-Step In Vitro-In Vivo Correlations Based on USP IV Dynamic Dissolution Applied to Four Sodium Montelukast Products

Pharmaceutics ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 690
Author(s):  
Mercedes Prieto-Escolar ◽  
Juan J. Torrado ◽  
Covadonga Álvarez ◽  
Alejandro Ruiz-Picazo ◽  
Marta Simón-Vázquez ◽  
...  
Keyword(s):  
Test Procedure ◽  
Sodium Dodecyl ◽  
Weak Acid ◽  
Added Value ◽  
Time Scaling ◽  
One Step ◽  
Flow Through ◽  
Low Solubility

Montelukast is a weak acid drug characterized by its low solubility in the range of pH 1.2 to 4.5, which may lead to dissolution-limited absorption. The aim of this paper is to develop an in vivo predictive dissolution method for montelukast and to check its performance by establishing a level-A in vitro-in vivo correlation (IVIVC). During the development of a generic film-coated tablet formulation, two clinical trials were done with three different experimental formulations to achieve a similar formulation to the reference one. A dissolution test procedure with a flow-through cell (USP IV) was used to predict the in vivo absorption behavior. The method proposed is based on a flow rate of 5 mL/min and changes of pH mediums from 1.2 to 4.5 and then to 6.8 with standard pharmacopoeia buffers. In order to improve the dissolution of montelukast, sodium dodecyl sulfate was added to the 4.5 and 6.8 pH mediums. Dissolution profiles in from the new method were used to develop a level-A IVIVC. One-step level-A IVIVC was developed from dissolution profiles and fractions absorbed obtained by the Loo–Riegelman method. Time scaling with Levy’s plot was necessary to achieve a linear IVIVC. One-step differential equation-based IVIVC was also developed with a time-scaling function. The developed method showed similar results to a previously proposed biopredictive method for montelukast, and the added value showed the ability to discriminate among different release rates in vitro, matching the in vivo clinical bioequivalence results.

scholarly journals β-Zeolite Assisted Lignin-First Fractionation in a Flow-Through Reactor

2021 ◽  
Author(s):  
Alexei Kramarenko ◽  
Deniz Etit ◽  
G. Laudadio ◽  
Fernanda Neira Dangelo
Keyword(s):  
Structural Changes ◽  
Catalyst Deactivation ◽  
Acid Sites ◽  
Catalyst Recycling ◽  
Mixed Regime ◽  
Rate Limiting Step ◽  
Lignocellulosic Feedstocks ◽  
One Step ◽  
Flow Through ◽  
Aromatic Monomer

<p>Lignin is one of the main constituents of lignocellulosic biomass, whose valorization is essential for an economically feasible biorefinery process scheme[1]. In the present work, a hydrogen-free one step catalytic fractionation of woody biomass using commercial b-zeolite as catalyst in a flow-through reactor was carried out, leading to a maximum aromatic monomer yield of 20.5 wt.%. Birch, spruce and walnut shells were used and compared as lignocellulosic feedstocks. Relevant insights in the reaction mechanism were obtained through 2D HSQC NMR analysis, revealing that b-O-4 cleavage is catalyzed by the zeolite. To optimize system operation, a rate limiting step analysis was performed by using different reactor configurations. It was found that the system operated in a mixed regime where the rates of both solvolytic delignification and zeolite-based depolymerization/dehydration affect the net rate of aromatic monomer production. Oxalic acid addition was found to enhance monomer production at moderate concentrations by improving solvolysis; however, it caused structural changes to the zeolite leading to lower monomer yields at higher concentrations. Zeolite stability was assessed through catalyst recycling and characterization using NH<sub>3</sub>-TPD, XRD, N<sub>2</sub> physisorption and TGA. Main catalyst deactivation mechanisms were found to be coking and leaching, respectively leading to larger pore size and lower concentration of acid sites.</p>

Sign in / Sign up

Export Citation Format

Share Document