Multi-wavelength diffractive beam shaper for rectangular flattop spots in flow cytometer (Conference Presentation)

2020 ◽  
Author(s):  
Jingjing Zhao ◽  
Yong Han ◽  
Zeheng Jiao ◽  
Zixi Chao ◽  
Attila Tárnok ◽  
...  
Keyword(s):  
Flow Cytometer ◽  
Multi Wavelength

A Micromachine-Based Flow Cytometer Chip Integrated with Micro-Pumps/Valves for Multi-Wavelength Detection Applications

2006 ◽  
Vol 505-507 ◽  
pp. 637-642 ◽  
Author(s):  
Chen Min Chang ◽  
S.K. Hsiung ◽  
Gwo Bin Lee
Keyword(s):  
Optical Fibers ◽  
Fluorescent Dyes ◽  
Flow Cytometer ◽  
Cell Counting ◽  
Hydrodynamic Focusing ◽  
Fast Analysis ◽  
Focusing Effect ◽  
Multi Wavelength ◽  
Analysis System ◽  
Wavelength Detection

This study presents a new micromachine-based cell counting and sorting system capable of multi-wavelength detection for biological applications. Chip-based flow cytometers have been extensively investigated recently. Several unique features have been integrated on this new cell-analysis system. First, a series of new serpentine-shape pneumatic micro-pumps were used to drive sample and sheath flows and generate a hydrodynamic focusing effect. The control of fluids could be achieved with ease by using this approach. Multiple embedded optical fibers were then used to transmit the light source and collect induced fluorescence signals in and out of the chip device. Cells labeled with different fluorescent dyes could be then individually detected by corresponding fibers using lasers with different wavelengths. Finally, three pneumatic micro-valves downstream were used for cell sorting. The developed micro flow cytometer could be used for fast analysis of cell-related bio-medical applications.

Loss of Thrombin-Induced Ca2+ Mobilization in a Subpopulation of Platelets during Storage

1991 ◽  
Vol 66 (03) ◽  
pp. 350-354 ◽  
Author(s):  
Rob Fijnheer ◽  
Christa H E Homburg ◽  
Berend Hooibrink ◽  
Martine N Boomgaard ◽  
Dirk de Korte ◽  
...  
Keyword(s):  
Human Platelets ◽  
Flow Cytometer ◽  
Maximal Concentration ◽  
Gradual Decline ◽  
Platelet Storage ◽  
Functional Defect ◽  
Total Fluorescence ◽  
Induced Changes

SummaryThrombin-induced changes in cytosolic free Ca2+ ([Ca2+]i) were studied in human platelets that had been stored for up to 6 days. Changes in [Ca2+]i were measured with Indo-1-loaded platelets and quantitated with two different methods: (i) measurement of the changes in total fluorescence; (ii) measurement of the [Ca2+]i changes in individual platelets in a flow cytometer, allowing the detection of non-responding platelets. The maximal concentration of [Ca2+]i after stimulation with 0.5 U of thrombin/ml decreased from 544 ± 58 nM (mean ± SEM, n = 6) on day 0, to 276 ± 9 nM on day 3 and to 203 ± 23 nM on day 6. The percentage of platelets responding to 0.5 U of thrombin/ml declined from 90 ± 2% on day 0 to 72 ± 4% on day 3, and to 47 ± 8% on day 6. Nevertheless, also the responding platelets showed a decreased rise in [Ca2+]i.The study shows that during platelet storage a decrease in the rise in [Ca2+]i upon thrombin stimulation occurs. This decrease is partly due to the formation of a subpopulation of platelets that is completely unresponsive and partly due to a decreased responsiveness in the remainder of the platelets; it is not due to a gradual decline in [Ca2+]i rise in all platelets. This phenomenon provides new insight in the functional defect of stored platelets.

Observations for the Role of Flux rope Eruption in a Geoeffective Solar Flare

2014 ◽  
Vol 4 (2) ◽  
pp. 555-564
Author(s):  
A.M Aslam
Keyword(s):  
Solar Flare ◽  
Flux Rope ◽  
Magnetic Configuration ◽  
Solar Dynamics Observatory ◽  
Multi Wavelength ◽  
Solar Dynamics ◽  
Halo Coronal Mass Ejection ◽  
Mass Ejection ◽  
The Waves

On September 24, 2011 a solar flare of M 7.1 class was released from the Sun. The flare was observed by most of the space and ground based observatories in various wavebands. We have carried out a study of this flare to understand its causes on Sun and impact on earth. The flare was released from NOAA active region AR 11302 at 12:33 UT. Although the region had already produced many M class flares and one X- class flare before this flare, the magnetic configuration was not relaxed and still continued to evolve as seen from HMI observations. From the Solar Dynamics Observatory (SDO) multi-wavelength (131 Ã…, 171 Ã…, 304 Ã… and 1600Ã…) observations we identified that a rapidly rising flux rope triggered the flare although HMI observations revealed that magnetic configuration did not undergo a much pronounced change. The flare was associated with a halo Coronal Mass Ejection (CME) as recorded by LASCO/SOHO Observations. The flare associated CME was effective in causing an intense geomagnetic storm with minimum Dst index -103 nT. A radio burst of type II was also recorded by the WAVES/WIND. In the present study attempt is made to study the nature of coupling between solar transients and geospace.

Multi-wavelength imaging and its application as a plasma torch health monitor

1997 ◽  
Author(s):  
C. Winstead ◽  
W. Wang ◽  
R. Cook ◽  
G. Miller ◽  
C. Winstead ◽  
...  
Keyword(s):  
Plasma Torch ◽  
Multi Wavelength ◽  
Health Monitor

Identification of antibiotics in meat. Flow cytometry capabilities

Vsyo o myase ◽  
2020 ◽  
pp. 56-60
Author(s):  
Zayko E.V. ◽  
◽  
Kuznetsova O.A. ◽  
Bataeva D.S. ◽  
Grudistova M.A. ◽  
...  
Keyword(s):  
Raw Materials ◽  
Animal Husbandry ◽  
Flow Cytometer ◽  
Poultry Meat ◽  
Meat Processing ◽  
Beta Lactams ◽  
Antimicrobial Substances ◽  
Chemotherapy Drugs ◽  
Processing Plants ◽  
Meat Samples

The problem of the uncontrolled use of antibiotics currently remains unresolved. Step-by-step monitoring of meat using modern methods will reduce the risk of using contaminated meat raw materials for food production. Qualitative monitoring will identify samples containing residual antimicrobial substances. The use of methods for identifying groups of antibiotics will help narrow the search for antibiotics by expensive chromatographic methods. A study was carried out of beef, pork and poultry meat, which is used in meat processing plants in the production of raw smoked sausages, using two methods. At the first stage, using a qualitative microbiological method, the raw meat was evaluated for the presence of antimicrobial substances, then their group was determined using a NovoCyte flow cytometer. According to the results of a study on a flow cytometer, it was found that out of 10 groups of antibiotics that can be determined by the tested method, the group of lincosamides was not found in all meat samples. The most common groups of chemotherapy drugs in pork were sulfonamides – 29.6 %, tetracycline group – 18.5 % and beta-lactams – 14.8 %, and in beef aminoglycosides – 36.7 %, phenicols – 30 % and beta-lactams – 13.3 %. In poultry meat samples, the most common were sulfonamides – 23.2 %, fenicols – 23.2 %, and beta-lactams – 16 %. Five groups of antibiotics were found in all studied types of meat: fenicols, β-lactams, macrolides, polypeptide antibiotics, and quinolones. This indicates their widespread use in animal husbandry and poultry farming.

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