scholarly journals On-Chip Selective Capture and Detection of Magnetic Fingerprints of Malaria

Sensors ◽  
2020 ◽  
Vol 20 (17) ◽  
pp. 4972
Author(s):  
Francesca Milesi ◽  
Marco Giacometti ◽  
Lorenzo Pietro Coppadoro ◽  
Giorgio Ferrari ◽  
Gianfranco Beniamino Fiore ◽  
...  
Keyword(s):  
Magnetic Field Gradient ◽  
Optimum Conditions ◽  
Physical Concept ◽  
Multiphysics Simulations ◽  
Microfluidic Chamber ◽  
Impedance Variation ◽  
Close Proximity ◽  
Malaria Species ◽  
On Chip ◽  
Magnetophoretic Separation

The development of innovative diagnostic tests is fundamental in the route towards malaria eradication. Here, we discuss the sorting capabilities of an innovative test for malaria which allows the quantitative and rapid detection of all malaria species. The physical concept of the test exploits the paramagnetic property of infected erythrocytes and hemozoin crystals, the magnetic fingerprints of malaria common to all species, which allows them to undergo a selective magnetophoretic separation driven by a magnetic field gradient in competition with gravity. Upon separation, corpuscles concentrate at the surface of a silicon microchip where interdigitated electrodes are placed in close proximity to magnetic concentrators. The impedance variation proportional to the amount of attracted particles is then measured. The capability of our test to perform the selective detection of infected erythrocytes and hemozoin crystals has been tested by means of capture experiments on treated bovine red blood cells, mimicking the behavior of malaria-infected ones, and suspensions of synthetic hemozoin crystals. Different configuration angles of the chip with respect to gravity force and different thicknesses of the microfluidic chamber containing the blood sample have been investigated experimentally and by multiphysics simulations. In the paper, we describe the optimum conditions leading to maximum sensitivity and specificity of the test.

scholarly journals Transient microfluidic compartmentalization using actionable microfilaments for biochemical assays, cell culture and organs-on-chip

Lab on a Chip ◽  
2016 ◽  
Vol 16 (24) ◽  
pp. 4691-4701 ◽  
Author(s):  
Ayako Yamada ◽  
Renaud Renault ◽  
Aleksandra Chikina ◽  
Bastien Venzac ◽  
Iago Pereiro ◽  
...  
Keyword(s):  
Cell Culture ◽  
Biochemical Assays ◽  
Microfluidic Chamber ◽  
On Chip

Microfilaments are employed as removable partitions to divide a microfluidic chamber along centimeter lengths.

scholarly journals Label-free, real-time on-chip sensing of living cancer cell via grating-coupled surface plasmon resonance

2019 ◽  
Author(s):  
Giulia Borile ◽  
Stefano Rossi ◽  
Andrea Filippi ◽  
Enrico Gazzola ◽  
Pietro Capaldo ◽  
...  
Keyword(s):  
Surface Plasmon Resonance ◽  
Real Time ◽  
Surface Plasmon ◽  
Plasmon Resonance ◽  
Cell Number ◽  
Label Free ◽  
Cellular Processes ◽  
Spr Sensor ◽  
Microfluidic Chamber ◽  
On Chip

ABSTRACTThe application of nanotechnologies to address biomedical questions is a key strategy for innovation in biomedical research. Among others, a key point consists in the availability of nanotechnologies for monitoring cellular processes in a real-time and label-free approach. Here, we focused on a grating-coupled Surface Plasmon Resonance (GC-SPR) sensor exploiting phase interrogation. This sensor can be integrated in a microfluidic chamber that ensures cell viability and avoids cell stress. We report the calibration of the sensor response as a function of cell number and its application to monitor cell adhesion kinetics as well as cell response to an external stimulus. Our results show that GC-SPR sensors can offer a valuable alternative to prism-coupled or imaging SPR devices, amenable for microfluidic implementation.

scholarly journals Effective Control of the Optical Bistability of a Three-Level Quantum Emitter near a Nanostructured Plasmonic Metasurface

Photonics ◽  
2021 ◽  
Vol 8 (7) ◽  
pp. 285
Author(s):  
Hamid R. Hamedi ◽  
Emmanuel Paspalakis ◽  
Vassilios Yannopapas
Keyword(s):  
Quantum Interference ◽  
Optical Bistability ◽  
Information Science ◽  
Ring Cavity ◽  
Photonic Devices ◽  
Effective Control ◽  
Quantum Emitter ◽  
Close Proximity ◽  
On Chip ◽  
Optical Ring

We study, theoretically, the phenomena optical bistability and multistability of a hybrid quantum-plasmonic system immersed within an optical ring cavity. The hybrid quantum-plasmonic system consists of a three-level V-type quantum emitter and a two-dimensional plasmonic metasurface of gold nanoshells. The quantum emitter and the plasmonic metasurface are placed in close proximity to each other so that a strong quantum interference of spontaneous emission occurs, which enables the strong modification of optical-bistability/ multistability hysteresis curves. Along with this, the strong interaction between the emitter and the plasmonic metasurface allows for active control of the corresponding bistable threshold intensity. Furthermore, we show that by varying the metasurface-emitter separation, a transition from bistability to multistability of the hybrid system is observed. Lastly, by introducing an additional incoherent pumping in the system, we have the emergence of phenomena, such as probe absorption and gain, with or without population inversion. The results may find technological application in on-chip nanoscale photonic devices, optoelectronics and solid-state quantum information science.

A Silicon Nitride Based Shallow Trench Isolation with Side-Gate for CMOS Integration with MEMS Components for System-On-Chip Applications

2004 ◽  
Vol 833 ◽  
Author(s):  
Ali Gokirmak ◽  
Sandip Tiwari
Keyword(s):  
Silicon Nitride ◽  
System On Chip ◽  
Leakage Currents ◽  
Shallow Trench Isolation ◽  
Mems Resonators ◽  
High Temperature Anneal ◽  
Close Proximity ◽  
Trench Isolation ◽  
Electrostatic Control ◽  
On Chip

ABSTRACTWe have developed a hydrofluoric acid (HF) resistant, composite shallow trench isolation (STI) process for MOSFETs utilizing silicon nitride as isolation material for on-chip integration of micro-electro-mechanical (MEMS) resonators and CMOS devices. Peripheral leakage currents in silicon nitride isolated MOSFETs are suppressed by employing an independently controlled polysilicon side-gate, surrounding the active area of the devices. Electrostatic control of the threshold voltage at the device periphery alleviates the need for edge implants, resulting in increased thermal budget. Compatibility with HF release processes and high temperature anneal cycles allows integration of MEMS components in close proximity to CMOS devices for system-on-chip applications. nMOSFET devices fabricated using this composite STI process show excellent device characteristics.

scholarly journals Rapid prototyping of a multilayer microphysiological system for primary human intestinal epithelial culture

2018 ◽  
Author(s):  
Sanjin Hosic ◽  
Marissa L. Puzan ◽  
Will Lake ◽  
Fanny Zhou ◽  
Ryan A. Koppes ◽  
...  
Keyword(s):  
3D Cell Culture ◽  
Water Vapor Permeability ◽  
Flow Chamber ◽  
Vapor Permeability ◽  
Intestinal Epithelial ◽  
Proof Of Concept ◽  
Epithelial Culture ◽  
Close Proximity ◽  
On Chip ◽  
Basal Flow

Here we report benchtop fabrication of multilayer thermoplastic organs-on-chips via laser cut and assembly of double sided adhesives. Biocompatibility was evaluated with Caco-2 cells and primary human intestinal organoids. Chips with Luer fluidic interfaces were economical ($2 per chip) and were fabricated in just hours without use of specialized bonding techniques. Compared with control static Transwell™ cultures, Caco-2 and organoids cultured on chips formed confluent monolayers expressing tight junctions with low permeability. Caco-2 cells on chip differentiated ∼4 times faster compared to controls and produced mucus. To demonstrate the robustness of laser cut and assembly, we fabricated a dual membrane, tri-layer gut chip integrating 2D monolayers, 3D cell culture, and a basal flow chamber. As proof of concept, we co-cultured a human, differentiated monolayer and intact organoids in a chip with multi-layered contacting compartments. The epithelium exhibited 3D tissue structure and organoids formed in close proximity to the adjacent monolayer. The favorable features of thermoplastics, such as low gas and water vapor permeability, in addition to rapid, facile, and economical fabrication of multilayered devices, make laser cut and assembly an ideal fabrication technique for developing organs-on-chips and studying multicellular tissues.

Effects of Vincristine on Endothelial Microtubules in the Spinal Cord

1976 ◽  
Vol 34 ◽  
pp. 58-59
Author(s):  
John L. Beggs ◽  
John D. Waggener ◽  
Wanda Miller
Keyword(s):  
Spinal Cord ◽  
Biological Activity ◽  
Horseradish Peroxidase ◽  
Transport Mechanism ◽  
Vasogenic Edema ◽  
Vesicular Transport ◽  
Close Proximity

Microtubules (MT) are versatile organelles participating in a wide variety of biological activity. MT involvement in the movement and transport of cytoplasmic components has been well documented. In the course of our study on trauma-induced vasogenic edema in the spinal cord we have concluded that endothelial vesicles contribute to the edema process. Using horseradish peroxidase as a vascular tracer, labeled endothelial vesicles were present in all situations expected if a vesicular transport mechanism was in operation. Frequently,labeled vesicles coalesced to form channels that appeared to traverse the endothelium. The presence of MT in close proximity to labeled vesicles sugg ested that MT may play a role in vesicular activity.

Experiments with a scanning tunneling microscope (STM) mounted in a scanning electron microscope (SEM)

1986 ◽  
Vol 44 ◽  
pp. 636-639
Author(s):  
Oliver C. Wells ◽  
Mark E. Welland
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Mechanical Stability ◽  
Tunneling Current ◽  
Feedback System ◽  
Scanning Tunneling ◽  
Surface Profiling ◽  
Close Proximity ◽  
Metal Tip ◽  
Scanning Electron

Scanning tunneling microscopes (STM) exist in two versions. In both of these, a pointed metal tip is scanned in close proximity to the specimen surface by means of three piezos. The distance of the tip from the sample is controlled by a feedback system to give a constant tunneling current between the tip and the sample. In the low-end STM, the system has a mechanical stability and a noise level to give a vertical resolution of between 0.1 nm and 1.0 nm. The atomic resolution STM can show individual atoms on the surface of the specimen.A low-end STM has been put into the specimen chamber of a scanning electron microscope (SEM). The first objective was to investigate technological problems such as surface profiling. The second objective was for exploratory studies. This second objective has already been achieved by showing that the STM can be used to study trapping sites in SiO2.

Ultrastructure and Senescence in an Achloroplastic Mutant of Hordeum vulgare L. cv. Dyan

1992 ◽  
Vol 50 (1) ◽  
pp. 844-845
Author(s):  
R.H.M. Cross ◽  
C.E.J. Botha ◽  
A.K. Cowan ◽  
B.J. Hartley
Keyword(s):  
Cell Wall ◽  
Hordeum Vulgare ◽  
Leaf Tissue ◽  
Ultrastructural Changes ◽  
Hordeum Vulgare L ◽  
Mesophyll Cells ◽  
Lethal Mutant ◽  
Cytoplasmic Matrix ◽  
Close Proximity ◽  
Pinocytotic Vesicles

Senescence is an ordered degenerative process leading to death of individual cells, organs and organisms. The detection of a conditional lethal mutant (achloroplastic) of Hordeum vulgare has enabled us to investigate ultrastructural changes occurring in leaf tissue during foliar senescence.Examination of the tonoplast structure in six and 14 day-old mutant tissue revealed a progressive degeneration and disappearance of the membrane, apparently starting by day six in the vicinity of the mitochondria associated with the degenerating proplastid (Fig. 1.) where neither of the plastid membrane leaflets is evident (arrows, Fig. 1.). At this stage there was evidence that the mitochondrial membranes were undergoing retrogressive changes, coupled with disorganization of cristae (Fig. 2.). Proplastids (P) lack definitive prolamellar bodies. The cytoplasmic matrix is largely agranular, with few endoplasmic reticulum (ER) cisternae or polyribosomal aggregates. Interestingly, large numbers of actively-budding dictysomes, associated with pinocytotic vesicles, were observed in close proximity to the plasmalemma of mesophyll cells (Fig. 3.). By day 14 however, mesophyll cells showed almost complete breakdown of subcellular organelle structure (Fig. 4.), and further evidence for the breakdown of the tonoplast. The final stage of senescence is characterized by the solubilization of the cell wall due to expression and activity of polygalacturonase and/or cellulose. The presence of dictyosomes with associated pinocytotic vesicles formed from the mature face, in close proximity to both the plasmalemma and the cell wall, would appear to support the model proposed by Christopherson for the secretion of cellulase. This pathway of synthesis is typical for secretory glycoproteins.

Spectroscopic imaging of human disease

1996 ◽  
Vol 54 ◽  
pp. 884-885
Author(s):  
D.J. Meyerhoff
Keyword(s):  
Magnetic Field ◽  
Magnetic Resonance ◽  
Field Gradient ◽  
Human Disease ◽  
Morphological Changes ◽  
Magnetic Field Gradient ◽  
Spectroscopic Imaging ◽  
Resonance Spectroscopy ◽  
Tissue Water

Magnetic Resonance Imaging (MRI) observes tissue water in the presence of a magnetic field gradient to study morphological changes such as tissue volume loss and signal hyperintensities in human disease. These changes are mostly non-specific and do not appear to be correlated with the range of severity of a certain disease. In contrast, Magnetic Resonance Spectroscopy (MRS), which measures many different chemicals and tissue metabolites in the millimolar concentration range in the absence of a magnetic field gradient, has been shown to reveal characteristic metabolite patterns which are often correlated with the severity of a disease. In-vivo MRS studies are performed on widely available MRI scanners without any “sample preparation” or invasive procedures and are therefore widely used in clinical research. Hydrogen (H) MRS and MR Spectroscopic Imaging (MRSI, conceptionally a combination of MRI and MRS) measure N-acetylaspartate (a putative marker of neurons), creatine-containing metabolites (involved in energy processes in the cell), choline-containing metabolites (involved in membrane metabolism and, possibly, inflammatory processes),

Gut microbiome a promising target for management of respiratory diseases

2020 ◽  
Vol 477 (14) ◽  
pp. 2679-2696
Author(s):  
Riddhi Trivedi ◽  
Kalyani Barve
Keyword(s):  
Respiratory Diseases ◽  
New Technology ◽  
Bacterial Flora ◽  
Systemic Circulation ◽  
The Body ◽  
Lung Pathology ◽  
Promising Target ◽  
Current Therapies ◽  
Intestinal Microbial Flora ◽  
On Chip

The intestinal microbial flora has risen to be one of the important etiological factors in the development of diseases like colorectal cancer, obesity, diabetes, inflammatory bowel disease, anxiety and Parkinson's. The emergence of the association between bacterial flora and lungs led to the discovery of the gut–lung axis. Dysbiosis of several species of colonic bacteria such as Firmicutes and Bacteroidetes and transfer of these bacteria from gut to lungs via lymphatic and systemic circulation are associated with several respiratory diseases such as lung cancer, asthma, tuberculosis, cystic fibrosis, etc. Current therapies for dysbiosis include use of probiotics, prebiotics and synbiotics to restore the balance between various species of beneficial bacteria. Various approaches like nanotechnology and microencapsulation have been explored to increase the permeability and viability of probiotics in the body. The need of the day is comprehensive study of mechanisms behind dysbiosis, translocation of microbiota from gut to lung through various channels and new technology for evaluating treatment to correct this dysbiosis which in turn can be used to manage various respiratory diseases. Microfluidics and organ on chip model are emerging technologies that can satisfy these needs. This review gives an overview of colonic commensals in lung pathology and novel systems that help in alleviating symptoms of lung diseases. We have also hypothesized new models to help in understanding bacterial pathways involved in the gut–lung axis as well as act as a futuristic approach in finding treatment of respiratory diseases caused by dysbiosis.

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