A low-voltage electrostatically actuated MEMS scanner for in vivo biomedical imaging

2003 ◽  
Author(s):  
T.W. Yeow ◽  
K.Y. Lim ◽  
B. Wilson ◽  
A.A. Goldenberg
Keyword(s):  
Biomedical Imaging ◽  
Low Voltage ◽  
Electrostatically Actuated

UV-Trained and Metal-Enhanced Fluorescence of Biliverdin and Biliverdin Nanoparticles

Nanoscale ◽  
2021 ◽  
Author(s):  
Parinaz Fathi ◽  
Ayman Roslend ◽  
Kritika Mehta ◽  
Parikshit Moitra ◽  
Kai Zhang ◽  
...  
Keyword(s):  
Quantum Yield ◽  
Fluorescence Quantum Yield ◽  
Biomedical Imaging ◽  
Enhanced Fluorescence ◽  
Metal Enhanced Fluorescence

Increasing the fluorescence quantum yield of fluorophores is of great interest for in vitro and in vivo biomedical imaging applications. At the same time, photobleaching and photodegradation resulting from continuous...

Metal chelate grafting at the surface of mesoporous silica nanoparticles (MSNs): physico-chemical and biomedical imaging assessment

2015 ◽  
Vol 3 (5) ◽  
pp. 748-758 ◽  
Author(s):  
Myriam Laprise-Pelletier ◽  
Meryem Bouchoucha ◽  
Jean Lagueux ◽  
Pascale Chevallier ◽  
Roger Lecomte ◽  
...  
Keyword(s):  
Mesoporous Silica ◽  
Silica Nanoparticles ◽  
Biomedical Imaging ◽  
Mesoporous Silica Nanoparticles ◽  
Metal Chelate ◽  
Chemical Characterization ◽  
Physico Chemical

A physico-chemical characterization and dual in vivo imaging (PET/MRI) of MSNs functionalized with DTPA and labeled with Gd3+ and 64Cu2+.

Low-voltage and high-voltage TEM observations on MWCNTs of rat in vivo

2009 ◽  
Vol 19 (2-3) ◽  
pp. 93-99
Author(s):  
Norihito Sakaguchi ◽  
Fumio Watari ◽  
Atsuro Yokoyama ◽  
Yoshinobu Nodasaka ◽  
Hideki Ichinose
Keyword(s):  
High Voltage ◽  
Low Voltage

scholarly journals Voltage–Amplitude Response of Superharmonic Resonance of Second Order of Electrostatically Actuated MEMS Cantilever Resonators

2019 ◽  
Vol 14 (3) ◽  
Author(s):  
Dumitru I. Caruntu ◽  
Martin A. Botello ◽  
Christian A. Reyes ◽  
Julio S. Beatriz
Keyword(s):  
Numerical Integration ◽  
Multiple Scales ◽  
Low Voltage ◽  
Second Order ◽  
Voltage Amplitude ◽  
Amplitude Response ◽  
Superharmonic Resonance ◽  
Bifurcation Points ◽  
Electrostatically Actuated ◽  
Modes Of Vibration

This paper investigates the voltage–amplitude response of superharmonic resonance of second order (order two) of alternating current (AC) electrostatically actuated microelectromechanical system (MEMS) cantilever resonators. The resonators consist of a cantilever parallel to a ground plate and under voltage that produces hard excitations. AC frequency is near one-fourth of the natural frequency of the cantilever. The electrostatic force includes fringe effect. Two kinds of models, namely reduced-order models (ROMs), and boundary value problem (BVP) model, are developed. Methods used to solve these models are (1) method of multiple scales (MMS) for ROM using one mode of vibration, (2) continuation and bifurcation analysis for ROMs with several modes of vibration, (3) numerical integration for ROM with several modes of vibration, and (4) numerical integration for BVP model. The voltage–amplitude response shows a softening effect and three saddle-node bifurcation points. The first two bifurcation points occur at low voltage and amplitudes of 0.2 and 0.56 of the gap. The third bifurcation point occurs at higher voltage, called pull-in voltage, and amplitude of 0.44 of the gap. Pull-in occurs, (1) for voltage larger than the pull-in voltage regardless of the initial amplitude and (2) for voltage values lower than the pull-in voltage and large initial amplitudes. Pull-in does not occur at relatively small voltages and small initial amplitudes. First two bifurcation points vanish as damping increases. All bifurcation points are shifted to lower voltages as fringe increases. Pull-in voltage is not affected by the damping or detuning frequency.

Controlling Assembly of Paired Gold Clusters within Apoferritin Nanoreactor for in Vivo Kidney Targeting and Biomedical Imaging

2011 ◽  
Vol 133 (22) ◽  
pp. 8617-8624 ◽  
Author(s):  
Cuiji Sun ◽  
Hui Yang ◽  
Yi Yuan ◽  
Xin Tian ◽  
Liming Wang ◽  
...  
Keyword(s):  
Biomedical Imaging ◽  
Gold Clusters

scholarly journals Electrical Stimulation Activates Fibroblasts through the Elevation of Intracellular Free Ca2+: Potential Mechanism of Pelvic Electrical Stimulation Therapy

2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Suting Li ◽  
Danhua Lu ◽  
Jianming Tang ◽  
Jie Min ◽  
Ming Hu ◽  
...  
Keyword(s):  
Electrical Stimulation ◽  
Nuclear Translocation ◽  
Low Voltage ◽  
Second Messenger ◽  
Vaginal Wall ◽  
Downstream Signaling ◽  
Physiological Processes ◽  
L929 Fibroblast ◽  
Intracellular Ca

Ca2+ is an important ion in response to electrical stimulation (ES) and acts as second messenger in the regulation of various physiological processes. Pelvic floor electrical stimulation (PES) is a low-voltage clinical application, available for urinary incontinence (UI) treatment. Fibroblasts, as the main cellular component of vaginal wall and pelvic ligament, play an important role in the maintenance of pelvic health. We studied the effect of ES on fibroblasts in this study. ES was conducted with electrotaxis chambers on L929 fibroblast and the ES parameter was 100 mV/mm×2h. The results showed that ES increased intracellular Ca2+ concentration, promoted the expression of PCNA, CyclinB1, and CyclinD1, and increased the proportion of cells in S and G2 phages. After ES, fibroblasts get activated and proliferated. Besides, BAPTA-AM, a membrane permeated chelator for intracellular free Ca2+, partially inhibited the effect of ES on fibroblasts activation and proliferation promotion. Furthermore, we elucidated that Ca2+, as a second messenger and upstream signal for Smads and Akt signaling, regulated ES-induced nuclear translocation of smad2/3, phosphorylation of smad2/3, Akt, and GSK3β. Finally, we validated the effect of ES on PES mouse model. The results indicated that PES promoted the activation and proliferation of fibroblasts in vivo. In conclusion, we verify that ES can elevate the concentration of intracellular Ca2+ and activate its downstream signaling and then promote the activation of fibroblasts, which may be one of the mechanisms of PES therapy.

scholarly journals Handheld nonlinear microscope system comprising a 2 MHz repetition rate, mode-locked Yb-fiber laser for in vivo biomedical imaging

2016 ◽  
Vol 7 (9) ◽  
pp. 3531 ◽  
Author(s):  
Ádám Krolopp ◽  
Attila Csákányi ◽  
Dóra Haluszka ◽  
Dániel Csáti ◽  
Lajos Vass ◽  
...  
Keyword(s):  
Fiber Laser ◽  
Repetition Rate ◽  
Biomedical Imaging

Multifunctional nanoprobes based on upconverting lanthanide doped CaF2: towards biocompatible materials for biomedical imaging

2014 ◽  
Vol 2 (9) ◽  
pp. 1158-1171 ◽  
Author(s):  
Irene Xochilt Cantarelli ◽  
Marco Pedroni ◽  
Fabio Piccinelli ◽  
Pasquina Marzola ◽  
Federico Boschi ◽  
...  
Keyword(s):  
Mr Imaging ◽  
Biomedical Imaging ◽  
Inflammatory Cytokine ◽  
Biocompatible Materials ◽  
Cytokine Secretion

Lanthanide doped CaF2 nanoparticles are useful for in vivo optical and MR imaging and as nanothermometer probes, which do not induce pro-inflammatory cytokine secretion.

scholarly journals Electrochemistry as a surrogate for protein phosphorylation: voltage-controlled assembly of reflectin A1

2020 ◽  
Vol 17 (173) ◽  
pp. 20200774
Author(s):  
Sheng-Ping Liang ◽  
Robert Levenson ◽  
Brandon Malady ◽  
Michael J. Gordon ◽  
Daniel E. Morse ◽  
...  
Keyword(s):  
Low Voltage ◽  
Selective Reduction ◽  
Structure And Function ◽  
Fine Tuning ◽  
Primary Amines ◽  
Environmental Signals ◽  
Instrument Measuring ◽  
And Function

Phosphorylation is among the most widely distributed mechanisms regulating the tunable structure and function of proteins in response to neuronal, hormonal and environmental signals. We demonstrate here that the low-voltage electrochemical reduction of histidine residues in reflectin A1, a protein that mediates the neuronal fine-tuning of colour reflected from skin cells for camouflage and communication in squids, acts as an in vitro surrogate for phosphorylation in vivo , driving the assembly previously shown to regulate its function. Using micro-drop voltammetry and a newly designed electrochemical cell integrated with an instrument measuring dynamic light scattering, we demonstrate selective reduction of the imidazolium side chains of histidine in monomers, oligopeptides and this complex protein in solution. The formal reduction potential of imidazolium proves readily distinguishable from those of hydronium and primary amines, allowing unequivocal confirmation of the direct and energetically selective deprotonation of histidine in the protein. The resulting ‘electro-assembly’ provides a new approach to probe, understand, and control the mechanisms that dynamically tune protein structure and function in normal physiology and disease. With its abilities to serve as a surrogate for phosphorylation and other mechanisms of charge neutralization, and to potentially isolate early intermediates in protein assembly, this method may be useful for analysing never-before-seen early intermediates in the phosphorylation-driven assembly of other proteins in normal physiology and disease.

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