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Journal of Dairy Science Oct 2020Elevated temperature is often an indicator of an immune response and used in the diagnosis of illness in dairy calves; however, measuring rectal temperature is labor...
Elevated temperature is often an indicator of an immune response and used in the diagnosis of illness in dairy calves; however, measuring rectal temperature is labor intensive and often not measured daily on the farm. The objective of this study was to measure body temperature using a microchip and determine an appropriate implant site that would passively read body temperature in dairy calves. First, the precision of the temperature microchips and the rectal thermometer were tested ex vivo. Then, Holstein bull calves (n = 12) at 14 ± 12 d (mean ± SD) of age were implanted with microchips subcutaneously by the scutulum of the ear, subcutaneously in the upper scapula (SCAP), and intramuscularly in the trapezius muscle of the neck. One week after implantation, a temperature reading was taken for every microchip implant site using a radiofrequency ID (RFID) reader, as well as rectally and in the tympanic membrane using a digital thermometer every 60 min for 24 h in each calf (hereafter, the hourly study). Additionally, microchip readings and rectal temperatures were taken daily at 0800 h from 8 wk of age (n = 9; 57 ± 12 d of age) until 2 wk postweaning for a subset of the bull calves used in the hourly study (hereafter, the daily study). In the ex vivo trial, the microchip readings were very highly correlated with the rectal thermometer (r = 0.96), and the average coefficient of variation between microchip readings was very low (0.12 ± 0.03%). The relationships between the microchip readings within ear, SCAP, and neck and rectal and tympanic temperatures were analyzed using Pearson correlations and Bland-Altman plots. The ear and neck readings were strongly correlated for the hourly study [individual animal correlation; median (Q1, Q3), r = 0.78 (0.73, 0.84)] and for the daily study [r = 0.79 (0.73, 0.89)] across calves. However, rectal temperature was not significantly correlated with ear, SCAP, neck, or tympanic temperature for the daily and hourly studies. Results suggest that temperature microchips measure temperature appropriately, but temperature is dependent upon the implant site in calves, and temperature measured at ear, SCAP, and neck implant sites cannot be used to estimate rectal temperature. Future research should determine thresholds for fever that are specific to implant sites in calves.
Topics: Animals; Cattle; Male; Body Temperature; Cattle Diseases; Dairying; Fever; Implants, Experimental; Lab-On-A-Chip Devices; Neck; Rectum; Thermometers
PubMed: 32828511
DOI: 10.3168/jds.2019-17999 -
Journal of Diabetes and Metabolic... Dec 2019In this paper, the effect of the position of the inlet and outlet microchannels on the flow profile and the geometry of the recognition chamber for sample pre-treatment...
OBJECTIVES
In this paper, the effect of the position of the inlet and outlet microchannels on the flow profile and the geometry of the recognition chamber for sample pre-treatment in an electrochemical biosensor to be used in osteoporosis management were investigated.
METHODS
All numerical computation presented in this work were performed using COMSOL Multiphysics and Fluent. Simulation was performed for a three-dimensional, incompressible Navier-Stokes flow and so explicit biphasic volume of fluid (VOF) equations were used.
RESULTS
In the designed microfluidic system, a pressure-driven laminar flow with no-slip boundary condition was responsible for fluid actuation through microchannels in a reproducible approach. Based on the simulation results, the number of outlets was increased and the angel through which the inlets and outlets were attached to the microchamber was changed so that the dead volume would be eliminated and the fluid flow trajectory, the velocity field and pressure were evenly distributed across the chamber. The Re number in the inlets was equal to 4.41, suggesting a laminar flow at this site.
CONCLUSION
The simulation results along with the fact that the design change was tested using laser ablated tape and a color dye at different steps provided the researchers with the opportunity to study the changes in a fast and accurate but cheap method. The absence of backflow helps with the cross-talk concern in the channels and the lack of bubbles and complete coverage of the chamber helps with a better surface modification and thus better sensing performance.
PubMed: 31890659
DOI: 10.1007/s40200-019-00418-x -
Scientific Reports Oct 2019While microfluidic systems model aspects of metastasis, they are limited to artificially created tissues of limited complexity. We set out to develop an in vitro model...
While microfluidic systems model aspects of metastasis, they are limited to artificially created tissues of limited complexity. We set out to develop an in vitro model of tumor cell migration from a primary tumor to a distant site that allows use of tissue. Accordingly, we created a macrofluidic model using culture plate wells connected with type I collagen-coated large bore tubing and has recirculating media. Green fluorescent protein-positive prostate carcinoma cells in a hydrogel or excised tumor xenografts from mice were placed into primary tumor sites and either human bone stromal cells (HS-5) in a hydrogel or human-derived bone chips were seeded into metastatic sites. Cells from the primary sites migrated to and grew in metastatic sites. Bone enhanced growth at metastatic sites and established a CXCL12 gradient that was higher in metastatic versus primary sites. AMD3100-mediated inhibition of CXCL12 function reduced the number of cells targeting the bone at the metastatic sites. In summary, we have developed a macrofluidic metastasis model that allows incorporation of tumor and metastatic microenvironment tissues and models chemotaxis. This system allows for incorporation of tumor heterogeneity and inclusion of an intact microenvironment. These features will facilitate identification of mechanisms and therapeutics for bone metastasis.
Topics: Animals; Bone Neoplasms; Cancellous Bone; Cell Movement; Chemokine CXCL12; Femur Head; Green Fluorescent Proteins; Heterografts; Humans; Hydrogels; Lab-On-A-Chip Devices; Male; Mice; Mice, Nude; Microchip Analytical Procedures; PC-3 Cells; Prostatic Neoplasms; Stromal Cells; Transduction, Genetic; Tumor Microenvironment
PubMed: 31628348
DOI: 10.1038/s41598-019-50577-3 -
Micromachines Sep 2019The rapid and reliable detection of chemical and biological agents in the field is important for many applications such as national security, environmental monitoring,...
The rapid and reliable detection of chemical and biological agents in the field is important for many applications such as national security, environmental monitoring, infectious diseases screening, and so on. Current commercially available devices may suffer from low field deployability, specificity, and reproducibility, as well as a high false alarm rate. This paper reports the development of a portable lab-on-a-chip device that could address these issues. The device integrates a polymer multiplexed microchip system, a contactless conductivity detector, a data acquisition and signal processing system, and a graphic/user interface. The samples are pre-treated by an on-chip capillary electrophoresis system. The separated analytes are detected by conductivity-based microsensors. Extensive studies are carried out to achieve satisfactory reproducibility of the microchip system. Chemical warfare agents soman (GD), sarin (GB), O-ethyl S-[2-diisoproylaminoethyl] methylphsophonothioate (VX), and their degradation products have been tested on the device. It was demonstrated that the device can fingerprint the tested chemical warfare agents. In addition, the detection of ricin and metal ions in water samples was demonstrated. Such a device could be used for the rapid and sensitive on-site detection of both chemical and biological agents in the future.
PubMed: 31527486
DOI: 10.3390/mi10090617 -
Scientific Reports May 2019The demand to perform forensic DNA profiling outside of centralized laboratories and on the crime scene is increasing. Several criminal investigations would benefit...
The demand to perform forensic DNA profiling outside of centralized laboratories and on the crime scene is increasing. Several criminal investigations would benefit tremendously from having DNA based information available in the first hours rather than days or weeks. However, due to the complexity and time-consuming nature of standard DNA fingerprinting methods, rapid and automated analyses are hard to achieve. We here demonstrate the implementation of an alternative DNA fingerprinting method in a single microchip. By combining PCR amplification and HyBeacon melting assays in a silicon Lab-on-a-chip (LoC), a significant step towards rapid on-site DNA fingerprinting is taken. The small form factor of a LoC reduces reagent consumption and increases portability. Additional miniaturization is achieved through an integrated heating element covering 24 parallel micro-reactors with a reaction volume of 0.14 µl each. The high level of parallelization allows the simultaneous analysis of 4 short tandem repeat (STR) loci and the amelogenin gender marker commonly included in forensic DNA analysis. A reference and crime scene sample can be analyzed simultaneously for direct comparison. Importantly, by using industry-standard semiconductor manufacturing processes, mass manufacturability can be guaranteed. Following assay design and optimization, complete 5-loci profiles could be robustly generated on-chip that are on par with those obtained using conventional benchtop real-time PCR thermal cyclers. Together, our results are an important step towards the development of commercial, mass-produced, portable devices for on-site testing in forensic DNA analysis.
Topics: DNA; DNA Fingerprinting; Equipment Design; Forensic Genetics; Humans; Lab-On-A-Chip Devices; Nucleic Acid Denaturation; Polymerase Chain Reaction; Silicon
PubMed: 31089203
DOI: 10.1038/s41598-019-43946-5 -
Theranostics 2019A common form of treatment for patients with hepatocellular carcinoma (HCC) is transarterial radioembolization (TARE) with non-degradable glass or resin microspheres...
A common form of treatment for patients with hepatocellular carcinoma (HCC) is transarterial radioembolization (TARE) with non-degradable glass or resin microspheres (MS) labeled with Y (Y-MS). To further simplify the dosimetry calculations in the clinical setting, to have more control over the particle size and to change the permanent embolization to a temporary one, we developed uniformly-sized, biodegradable Re-labeled MS (Re-MS) as a new and easily imageable TARE agent. MS made of poly(-lactic acid) were produced in a flow focusing microchip. The MS were labeled with Re using a customized kit. An orthotopic HCC animal model was developed in male Sprague Dawley rats by injecting N1-S1 cells directly into the liver using ultrasound guidance. A suspension of Re-MS was administered via hepatic intra-arterial catheterization 2 weeks post-inoculation of the N1-S1 cells. The rats were imaged by SPECT 1, 24, 48, and 72 h post-radioembolization. The spherical Re-MS had a diameter of 41.8 ± 6.0 µm ( = 14.5%). The site and the depth of the injection of N1-S1 cells were controlled by visualization of the liver in sonograms. Single 0.5 g tumors were grown in all rats. Re-MS accumulated in the liver with no deposition in the lungs. Re decays to stable Os by emission of β particles with similar energy to those emitted by Y while simultaneously emitting γ photons, which were imaged directly by single photon computed tomography (SPECT). Using Monte Carlo methods, the dose to the tumors was calculated to be 3-6 times larger than to the healthy liver tissue. Re-MS have the potential to become the next generation of β-emitting MS for TARE. Future work revolves around the investigation of the therapeutic potential of Re-MS in a large-scale, long-term preclinical study as well as the evaluation of the clinical outcomes of using Re-MS with different sizes, from 20 to 50 µm.
Topics: Animals; Carcinoma, Hepatocellular; Disease Models, Animal; Drug Carriers; Embolization, Therapeutic; Humans; In Vivo Dosimetry; Liver Neoplasms; Microspheres; Polyesters; Radioisotopes; Radiotherapy; Rats, Sprague-Dawley; Rhenium; Treatment Outcome
PubMed: 30809314
DOI: 10.7150/thno.29381 -
ACS Sensors Oct 2018Rapid detection of bacteria and their susceptibility to specific antibiotics plays a vital role in microbial infection treatments. Antimicrobial susceptibility testing...
Rapid detection of bacteria and their susceptibility to specific antibiotics plays a vital role in microbial infection treatments. Antimicrobial susceptibility testing (AST) is a common measure to select effective drugs. However, the conventional practices, such as broth dilution, E-test, and disk diffusion, in clinical applications require a long turnaround time (∼3 days), thereby compromising treatments and increasing mortality. This study presents self-powered sensors for on-site microorganism monitoring and rapid AST based on functionalized microbeads. The microbead sensors are driven by Brownian motion, rendering external power unnecessary. Fluorescent microbeads ( d = 2 μm) were coated with vancomycin to capture bacteria. The growth and responses of Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus under antibiotic treatment were evaluated. The method showed stable selective binding despite the presence of some interferential substances, such as proteins and cells. Diffusivity change was strongly related to bacterial concentration. Accordingly, the diffusivity values of microbeads bound with motile and nonmotile bacteria exhibited specific patterns because of extra motility from microbes and increased particle diameter. Only a drop of microbead-bacteria suspension (∼5 μL) was needed in a microchip for each measurement. The microchip provided a steady environment for measurement over a few hours. By distinguishing the slope of the last four data points in the temporal diffusivity curve, bacterial susceptibility or resistance to specific antibiotics could be determined within a time frame of 2 h. The study provides insights into saving more lives by using a fast and robust AST technique in future clinical practice.
Topics: Anti-Bacterial Agents; Escherichia coli; Magnetics; Microbial Sensitivity Tests; Microchip Analytical Procedures; Microspheres; Staphylococcus aureus; Vancomycin
PubMed: 30221509
DOI: 10.1021/acssensors.8b00790 -
Analytical Chemistry Aug 2018Protein catalyzed capture agents (PCCs) are synthetic antibody surrogates that can target a wide variety of biologically relevant proteins. As a step toward developing a...
Protein catalyzed capture agents (PCCs) are synthetic antibody surrogates that can target a wide variety of biologically relevant proteins. As a step toward developing a high-throughput PCC pipeline, we report on the preparation of a barcoded rapid assay platform for the analysis of hits from PCC library screens. The platform is constructed by first surface patterning a micrometer scale barcode composed of orthogonal ssDNA strands onto a glass slide. The slide is then partitioned into microwells, each of which contains multiple copies of the full barcode. Biotinylated candidate PCCs from a click screen are assembled onto the barcode stripes using a complementary ssDNA-encoded cysteine-modified streptavidin library. This platform was employed to evaluate candidate PCC ligands identified from an epitope targeted in situ click screen against the two conserved allosteric switch regions of the Kirsten rat sarcoma (KRas) protein. A single microchip was utilized for the simultaneous evaluation of 15 PCC candidate fractions under more than a dozen different assay conditions. The platform also permitted more than a 10-fold savings in time and a more than 100-fold reduction in biological and chemical reagents relative to traditional multiwell plate assays. The best ligand was shown to exhibit an in vitro inhibition constant (IC) of ∼24 μM.
Topics: Allosteric Regulation; Allosteric Site; Biotinylation; DNA, Single-Stranded; Drug Evaluation, Preclinical; Enzyme Inhibitors; Humans; Microarray Analysis; Proto-Oncogene Proteins p21(ras); Streptavidin
PubMed: 29979578
DOI: 10.1021/acs.analchem.8b00706 -
Scientific Reports Jun 2018The demand for solutions to perform forensic DNA profiling outside of centralized laboratories is increasing. We here demonstrate highly sensitive STR amplification...
The demand for solutions to perform forensic DNA profiling outside of centralized laboratories is increasing. We here demonstrate highly sensitive STR amplification using a silicon micro-PCR (µPCR) chip. Exploiting industry-standard semiconductor manufacturing processes, a device was fabricated that features a small form factor thanks to an integrated heating element covering three parallel micro-reactors with a reaction volume of 0.5 µl each. Diluted reference DNA samples (1 ng-31 pg) were amplified on the µPCR chip using the forensically validated AmpFISTR Identifier Plus kit, followed by conventional capillary electrophoresis. Complete STR profiles were generated with input DNA quantities down to 62 pg. Occasional allelic dropouts were observed from 31 pg downward. On-chip STR profiles were compared with those of identical samples amplified using a conventional thermal cycler for direct comparison of amplification sensitivity in a forensic setting. The observed sensitivity was in line with kit specifications for both µPCR and conventional PCR. Finally, a rapid amplification protocol was developed. Complete STR profiles could be generated in less than 17 minutes from as little as 125 pg template DNA. Together, our results are an important step towards the development of commercial, mass-produced, relatively cheap, handheld devices for on-site testing in forensic DNA analysis.
Topics: DNA Fingerprinting; Forensic Genetics; Genetic Markers; Genotype; Humans; Microsatellite Repeats; Polymerase Chain Reaction; Silicon
PubMed: 29959383
DOI: 10.1038/s41598-018-28229-9 -
Journal of Neurophysiology Jul 2018Optogenetic manipulations are widely used for investigating the contribution of genetically identified cell types to behavior. Simultaneous electrophysiological...
Optogenetic manipulations are widely used for investigating the contribution of genetically identified cell types to behavior. Simultaneous electrophysiological recordings are less common, although they are critical for characterizing the specific impact of optogenetic manipulations on neural circuits in vivo. This is at least in part because combining photostimulation with large-scale electrophysiological recordings remains technically challenging, which also poses a limitation for performing extracellular identification experiments. Currently available interfaces that guide light of the appropriate wavelength into the brain combined with an electrophysiological modality suffer from various drawbacks such as a bulky size, low spatial resolution, heat dissipation, or photovoltaic artifacts. To address these challenges, we have designed and fabricated an integrated ultrathin neural interface with 12 optical outputs and 24 electrodes. We used the device to measure the effect of localized stimulation in the anterior olfactory cortex, a paleocortical structure involved in olfactory processing. Our experiments in adult mice demonstrate that because of its small dimensions, our novel tool causes far less tissue damage than commercially available devices. Moreover, optical stimulation and recording can be performed simultaneously, with no measurable electrical artifact during optical stimulation. Importantly, optical stimulation can be confined to small volumes with approximately single-cortical layer thickness. Finally, we find that even highly localized optical stimulation causes inhibition at more distant sites. NEW & NOTEWORTHY In this study, we establish a novel tool for simultaneous extracellular recording and optogenetic photostimulation. Because the device is built using established microchip technology, it can be fabricated with high reproducibility and reliability. We further show that even very localized stimulation affects neural firing far beyond the stimulation site. This demonstrates the difficulty in predicting circuit-level effects of optogenetic manipulations and highlights the importance of closely monitoring neural activity in optogenetic experiments.
Topics: Animals; Brain-Computer Interfaces; Electrodes; Evoked Potentials; Female; Mice; Mice, Inbred C57BL; Neurons; Optogenetics; Sensorimotor Cortex
PubMed: 29589813
DOI: 10.1152/jn.00888.2017