Dynamic Light Scattering Microrheology for Soft and Living Materials

AbstractAlthough, many conventional approaches have been used to measure viscosity of fluids, most methods do not allow non-contact, rapid measurements on small sample volume and have universal applicability to all fluids. Here, we demonstrate a simple yet universal viscometer, as proposed by Stokes more than a century ago, exploiting damping of capillary waves generated electrically and probed optically with sub-nanoscale precision. Using a low electric field local actuation of fluids we generate quasi-monochromatic propagating capillary waves and employ a pair of single-lens based compact interferometers to measure attenuation of capillary waves in real-time. Our setup allows rapid measurement of viscosity of a wide variety of polar, non-polar, transparent, opaque, thin or thick fluids having viscosity values varying over four orders of magnitude from $$10^{0}{-}10^{4}~\text{mPa} \, \text{s}$$ 10 0 - 10 4 mPa s . Furthermore, we discuss two additional damping mechanisms for nanomechanical capillary waves caused by bottom friction and top nano-layer appearing in micro-litre droplets. Such self-stabilized droplets when coupled with precision interferometers form interesting microscopic platform for picomechanical optofluidics for fundamental, industrial and medical applications.

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Ultrasensitive quantification of drug-metabolizing enzymes and transporters in small sample volume by microflow LC-MS/MS

Journal of Pharmaceutical Sciences ◽

10.1016/j.xphs.2021.03.020 ◽

2021 ◽

Author(s):

Deepak Suresh Ahire ◽

Abdul Basit ◽

Matthew Karasu ◽

Bhagwat Prasad

Keyword(s):

Sample Volume ◽

Small Sample ◽

Drug Metabolizing Enzymes ◽

Metabolizing Enzymes ◽

Small Sample Volume

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Aptamer-Based Detection of Ampicillin in Urine Samples

Antibiotics ◽

10.3390/antibiotics9100655 ◽

2020 ◽

Vol 9 (10) ◽

pp. 655

Author(s):

Matthew D. Simmons ◽

Lisa M. Miller ◽

Malin O. Sundström ◽

Steven Johnson

Keyword(s):

Health Care ◽

General Population ◽

Bacterial Resistance ◽

Sample Volume ◽

Small Sample ◽

Urine Samples ◽

Drug Resistant ◽

Relevant Range ◽

Small Sample Volume

The misuse of antibiotics in health care has led to increasing levels of drug resistant infections (DRI’s) occurring in the general population. Most technologies developed for the detection of DRI’s typically focus on phenotyping or genotyping bacterial resistance rather than on the underlying cause and spread of DRI’s; namely the misuse of antibiotics. An aptameric based assay has been developed for the monitoring of ampicillin in urine samples, for use in determining optimal antibiotic dosage and monitoring patient compliance with treatment. The fluorescently labelled aptamers were shown to perform optimally at pH 7, ideal for buffered clinical urine samples, with limits of detection as low as 20.6 nM, allowing for determination of ampicillin in urine in the clinically relevant range of concentrations (100 nM to 100 µM). As the assay requires incubation for only 1 h with a small sample volume, 50 to 150 µL, the test would fit within current healthcare pathways, simplifying the adoption of the technology.

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Automated HPLC screening of newborns for sickle cell anemia and other hemoglobinopathies

Clinical Chemistry ◽

10.1093/clinchem/42.5.704 ◽

1996 ◽

Vol 42 (5) ◽

pp. 704-710 ◽

Cited By ~ 41

Author(s):

J W Eastman ◽

R Wong ◽

C L Liao ◽

D R Morales

Keyword(s):

Quality Control ◽

Detection Limit ◽

Sickle Cell Anemia ◽

Sample Volume ◽

Small Sample ◽

Peak Resolution ◽

Automated Hplc ◽

Hb S ◽

Blood Spot ◽

Small Sample Volume

Abstract Automated HPLC is used to test dried blood-spot specimens from newborns for hemoglobins (Hb) F, A, S, C, E, and D. We present the method and report on its performance determined during >4 years of testing 2.5 x 10(6) newborns. The method features automated derivation of presumptive phenotypes; quantitative quality control and proficiency testing; throughput of one specimen per minute; small sample volume; hemoglobin concentrations quantified with an interlaboratory CV of 14-18%; retention times with interlaboratory CV of <2% and matching, within +/- 0.03 min, of laboratories and reagent lots; control of peak resolution; 0.5% detection limit for Hb S and C, and 1.0% for Hb F, A, E, and D; few interferences; and negligible background and carryover. Shortcomings of the method are the absence of microplate barcode identification and the need for manually pipetting the sample eluate into the microplate.

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Mechanical and Heterogeneous Properties of Coal and Rock Quantified and Mapped at the Microscale

Applied Sciences ◽

10.3390/app10010342 ◽

2020 ◽

Vol 10 (1) ◽

pp. 342 ◽

Cited By ~ 2

Author(s):

Changlun Sun ◽

Guichen Li ◽

Suhui Zhang ◽

Jiahui Xu ◽

Houqiang Yang

Keyword(s):

Mechanical Properties ◽

Fracture Toughness ◽

Convenient Method ◽

Elastic Moduli ◽

Averaging Method ◽

Sample Volume ◽

Small Sample ◽

Mechanical Parameters ◽

Experimental Technology ◽

Small Sample Volume

Due to the impossibility of obtaining intact standard experimental samples, it is difficult to test the mechanical properties of soft and broken coal and rock obtained from deep coal mines. So, an advanced experimental technology based on a small sample volume, nanoindentation technology, was introduced and used to measure the mechanical parameters of them. By using the averaging method, the hardness of shale, mudstone and coal are 1191.90 MPa, 674.95 MPa and 424.30 MPa, respectively; their elastic moduli are 20.39 GPa, 11.72 GPa and 5.47 GPa; and their fracture toughness were 1.66 MPa·m0.5, 1.28 MPa·m0.5 and 0.77 MPa·m0.5. These three mechanical parameters were used to quantify and map the heterogeneous properties of coal and rock for convenience and accuracy. For example, the inter quartile range (IQR) of the hardness of shale, mudstone, and coal are 1502.10 MPa, 1016.20 MPa and 54.64 MPa, respectively, meaning that coal has the best homogeneity among them. Nanoindentation technology provides researchers with a convenient method to conduct mechanical experiments at the microscale.

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Liquid chromatography in open tubes.

Clinical Chemistry ◽

10.1093/clinchem/30.9.1473 ◽

1984 ◽

Vol 30 (9) ◽

pp. 1473-1476 ◽

Cited By ~ 1

Author(s):

M P Maskarinec ◽

M J Sepaniak ◽

A T Balchunas ◽

J D Vargo

Keyword(s):

Liquid Chromatography ◽

Clinical Analysis ◽

Sample Volume ◽

Small Sample ◽

Separation Power ◽

Wide Applicability ◽

Further Development ◽

High Separation ◽

Detector Technology ◽

Small Sample Volume

Abstract Liquid chromatography in open tubes is evaluated for applicability to clinical analysis. The principal advantages of this technique include high separation power, reduced solvent consumption, and small sample volume requirements. Technology for the production of columns as small as 8 micron (i.d.) is described. Preliminary results are encouraging and, with further development in column and detector technology, the technique should find wide applicability in clinical analysis.

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Development of Micro Optical Diffusion Sensor Based on Laser Induced Dielectrophoresis

ASME 2009 Second International Conference on Micro/Nanoscale Heat and Mass Transfer, Volume 2 ◽

10.1115/mnhmt2009-18384 ◽

2009 ◽

Author(s):

Yoshihiro Taguchi ◽

Koichi Itani ◽

Akira Ebisui ◽

Yuji Nagasaka

Keyword(s):

Concentration Distribution ◽

High Speed ◽

High Efficiency ◽

Sample Volume ◽

Small Sample ◽

Micro Electro Mechanical Systems ◽

Measurement Principle ◽

Sinusoidal Pattern ◽

Chemical Fields ◽

Small Sample Volume

Micro-electro mechanical systems (MEMS) biochips realizing high-speed and high-efficiency of reaction and analysis attract much attention in medical as well as chemical fields. Especially, the miniaturized devices enabling small sample volume, arrayed, and portable measurement may become a powerful tool for material analysis and process control. We have proposed a novel micro optical diffusion sensor (MODS) which enables small sample volume, highspeed and non-contact measurement of diffusion coefficient of liquid sample. MODS consists of a pair of transparent electrodes (Al-doped Zinc oxide: AZO), a photoconductive layer (amorphous silicon: a-Si:H), two MEMS mirrors and excitation and probing fibers for inducing and detecting concentration distribution. The initial concentration distribution of sample is created by an opto-dielectrophoretic (opto-DEP) manipulation along with a sinusoidal pattern of irradiated beam on a photoconductive layer. In the present paper, the measurement principle is proposed, and the preliminary experiment using a bench top apparatus is reported.

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Liquid-chromatographic analysis for cyclosporine with use of a microbore column and small sample volume.

Clinical Chemistry ◽

10.1093/clinchem/32.7.1407 ◽

1986 ◽

Vol 32 (7) ◽

pp. 1407-1409 ◽

Cited By ~ 15

Author(s):

T Annesley ◽

K Matz ◽

L Balogh ◽

L Clayton ◽

D Giacherio

Keyword(s):

Chromatographic Analysis ◽

Glass Tube ◽

Sample Volume ◽

Small Sample ◽

Butyl Ether ◽

Microbore Columns ◽

Liquid Chromatographic Analysis ◽

Liquid Chromatographic ◽

Microbore Column ◽

Small Sample Volume

Abstract This liquid-chromatographic assay requires 0.2 to 0.5 mL of whole blood, avoids the use of diethyl ether, and consumes only 10 to 20% of the solvents used in prior methods. Sample preparation involves an acidic extraction with methyl-t-butyl ether, performed in a 13 X 100 mm disposable glass tube, then a short second extraction of the organic phase with sodium hydroxide. After evaporation of the methyl-t-butyl ether, chromatography is performed on an "Astec" 2.0-mm (i.d.) octyl column. We compared results by this procedure with those by use of earlier larger-scale extractions and their respective 4.6-mm (i.d.) columns; analytical recoveries of cyclosporins A and D were comparable with previous findings and results for patients' specimens were equivalent, but the microbore columns provided greatly increased resolution and sensitivity.

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