3PC-031 The influence of dead volume on reconstitution of injectable drugs

The design of a free piston compressor and an analysis on integrating an external combustion engine into the compressor design are presented in this article. A free piston compressor is a device which converts chemical energy to work on a volume of air through the kinetic energy of an inertia driven piston, which is not rigidly attached to a ground. An external combustion engine serves as in intermediate chamber which transfers combustion gases to a device to perform some work. The following discusses the design and experiments on an external combustion engine, with a focus on eliminating an injection holding force on a free piston compressor’s elastomeric membranes. The efficiency of the external combustion engine to transfer energy without significant losses due to heat, dead volume, air/fuel mixtures, and actuated valve speed are also presented.

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Integrated impedance sensing of liquid sample plug flow enables automated high throughput NMR spectroscopy

Microsystems & Nanoengineering ◽

10.1038/s41378-021-00253-2 ◽

2021 ◽

Vol 7 (1) ◽

Cited By ~ 1

Author(s):

Omar Nassar ◽

Mazin Jouda ◽

Michael Rapp ◽

Dario Mager ◽

Jan G. Korvink ◽

...

Keyword(s):

Nmr Spectroscopy ◽

High Throughput ◽

Plug Flow ◽

Microfluidic System ◽

High Resolution Spectroscopy ◽

Dead Volume ◽

Absolute Difference ◽

Immiscible Fluid ◽

Flow Sensors ◽

Novel Approach

AbstractA novel approach for automated high throughput NMR spectroscopy with improved mass-sensitivity is accomplished by integrating microfluidic technologies and micro-NMR resonators. A flow system is utilized to transport a sample of interest from outside the NMR magnet through the NMR detector, circumventing the relatively vast dead volume in the supplying tube by loading a series of individual sample plugs separated by an immiscible fluid. This dual-phase flow demands a real-time robust sensing system to track the sample position and velocities and synchronize the NMR acquisition. In this contribution, we describe an NMR probe head that possesses a microfluidic system featuring: (i) a micro saddle coil for NMR spectroscopy and (ii) a pair of interdigitated capacitive sensors flanking the NMR detector for continuous position and velocity monitoring of the plugs with respect to the NMR detector. The system was successfully tested for automating flow-based measurement in a 500 MHz NMR system, enabling high resolution spectroscopy and NMR sensitivity of 2.18 nmol s1/2 with the flow sensors in operation. The flow sensors featured sensitivity to an absolute difference of 0.2 in relative permittivity, enabling distinction between most common solvents. It was demonstrated that a fully automated NMR measurement of nine individual 120 μL samples could be done within 3.6 min or effectively 15.3 s per sample.

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Experimental and modeling based dead-volume detection for externally stirred tanks

Chemical Engineering Communications ◽

10.1080/00986445.2021.1903449 ◽

2021 ◽

pp. 1-15

Author(s):

Bálint Levente Tarcsay ◽

Janka Bobek-Nagy ◽

Attila Egedy

Keyword(s):

Dead Volume ◽

Stirred Tanks

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Impact of resistance to first-line and injectable drugs on treatment outcomes in MDR-TB

European Respiratory Journal ◽

10.1183/09031936.00099608 ◽

2009 ◽

Vol 33 (3) ◽

pp. 581-585 ◽

Cited By ~ 16

Author(s):

S. S. Hwang ◽

H-R. Kim ◽

H. J. Kim ◽

M. J. Kim ◽

S. M. Lee ◽

...

Keyword(s):

Treatment Outcomes ◽

First Line ◽

Injectable Drugs ◽

Mdr Tb

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On-Chip Fabrication of None-Dead-Volume Microtips for ESI-MS Applications

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.121-123.611 ◽

2007 ◽

Vol 121-123 ◽

pp. 611-614

Author(s):

Che Hsin Lin ◽

Jen Taie Shiea ◽

Yen Lieng Lin

Keyword(s):

Surface Tension ◽

Low Cost ◽

Microfluidic Channel ◽

Dead Volume ◽

Esi Ms ◽

Rapid Fabrication ◽

Chip Fabrication ◽

Novel Method ◽

On Chip ◽

Highly Uniform

This paper proposes a novel method to on-chip fabricate a none-dead-volume microtip for ESI-MS applications. The microfluidic chip and ESI tip are fabricated in low-cost plastic based materials using a simple and rapid fabrication process. A constant-speed-pulling method is developed to fabricate the ESI tip by pulling mixed PMMA glue using a 30-μm stainless wire through the pre-formed microfluidic channel. The equilibrium of surface tension of PMMA glue will result in a sharp tip after curing. A highly uniform micro-tip can be formed directly at the outlet of the microfluidic channel with minimum dead-volume zone. Detection of caffeine, myoglobin, lysozyme and cytochrome C biosamples confirms the microchip device can be used for high resolution ESI-MS applications.

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Increasing prevalence of resistance to second-line drugs among multidrug-resistant Mycobacterium tuberculosis isolates in Kuwait

Scientific Reports ◽

10.1038/s41598-021-87516-0 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Noura M. Al-Mutairi ◽

Suhail Ahmad ◽

Eiman Mokaddas

Keyword(s):

Drug Resistance ◽

Mycobacterium Tuberculosis ◽

Mutation Detection ◽

Susceptibility Testing ◽

Multidrug Resistant ◽

Genetic Mutations ◽

Second Line ◽

Injectable Drugs ◽

Mdr Tb ◽

Phenotypic Susceptibility

AbstractMolecular methods detect genetic mutations associated with drug resistance. This study detected resistance-conferring mutations in gyrA/gyrB for fluoroquinolones and rrs/eis genes for second-line injectable drugs (SLIDs) among multidrug-resistant Mycobacterium tuberculosis (MDR-TB) isolates in Kuwait. Fifty pansusceptible M. tuberculosis and 102 MDR-TB strains were tested. Phenotypic susceptibility testing was performed by MGIT 960 system using SIRE drug kit. GenoType MTBDRsl version 1 (gMTBDRslv1) and GenoType MTBDRsl version 2 (gMTBDRslv2) tests were used for mutation detection. Results were validated by PCR-sequencing of respective genes. Fingerprinting was performed by spoligotyping. No mutations were detected in pansusceptible isolates. gMTBDRslv1 detected gyrA mutations in 12 and rrs mutations in 8 MDR-TB isolates. gMTBDRsl2 additionally detected gyrB mutations in 2 and eis mutation in 1 isolate. Mutations in both gyrA/gyrB and rrs/eis were not detected. gMTBDRslv1 also detected ethambutol resistance-conferring embB mutations in 59 isolates. Although XDR-TB was not detected, frequency of resistance-conferring mutations for fluoroquinolones or SLIDs was significantly higher among isolates collected during 2013–2019 versus 2006–2012. Application of both tests is warranted for proper management of MDR-TB patients in Kuwait as gMTBDRslv2 detected resistance to fluoroquinolones and/or SLIDs in 3 additional isolates while gMTBDRslv1 additionally detected resistance to ethambutol in 58% of MDR-TB isolates.

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