5 research outputs found
A multiple modulation synthesis method with high spatial resolution for noninvasive neurostimulation.
Noninvasive neurostimulation plays a pivotal role in the direct control of neural circuits and the modulation of neuronal function. However, it is difficult to balance both spatial resolution and penetration depth when stimulating deep neurons. Here, we designed a multiple (time-division, frequency and polarity) modulation synthesis (MMS) method for noninvasively stimulating deep neurons with low-frequency envelopes. Compared to conventional transcranial electrical stimulation, we demonstrated that it can stimulate deep neurons at the desired firing rate (beat frequency) with higher spatial resolution via a computational model combining finite element analysis and Hodgkin-Huxley action potential model. Additionally, we measured the distribution of stimulus waveforms in saline solution to validate its effect. Taken together, the results of this study indicate that MMS stimulation with higher spatial resolution is steerable and might be a potential alternative to traditional implanted electrodes
Three-Dimensional Inverse Opal Photonic Crystal Substrates toward Efficient Capture of Circulating Tumor Cells
Artificial fractal
structures have attracted considerable scientific interest in circulating
tumor cells (CTCs) detection and capture, which plays a pivotal role
in the diagnosis and prognosis of cancer. Herein, we designed a bionic
TiO<sub>2</sub> inverse opal photonic crystal (IOPC) structure for
highly efficient immunocapture of CTCs by combination of a magnetic
Fe<sub>3</sub>O<sub>4</sub>@C6@silane nanoparticles with anti-EpCAM
(antiepithelial cell adhesion molecule) and microchannel structure.
Porous structure and dimension of IOPC TiO<sub>2</sub> can be precisely
controlled for mimicking cellular components, and anti-EpCAM antibody
was further modified on IOPC interface by conjugating with polydopamine
(PDA). The improvement of CTCs capture efficiency reaches a surprising
factor of 20 for the IOPC interface compared to that on flat glass,
suggesting that the IOPCs are responsible for the dramatic enhancement
of the capture efficiency of MCF-7 cells. IOPC substrate with pore
size of 415 nm leads to the optimal CTCs capture efficiency of 92%
with 1 mL/h. Besides the cell affinity, IOPCs also have the advantage
of light scattering property which can enhance the excitation and
emission light of fluorescence labels, facilitating the real-time
monitoring of CTCs capture. The IOPC-based platform demonstrates excellent
performance in CTCs capture, which will take an important step toward
specific recognition of disease-related rare cells