Micrometer and nanometer grooved surfaces have been determined to influence cellular orientation, morphology, and migration through contact guidance. Cells typically elongate along the direction of an underlying groove and often migrate with guidance provided by constraints of the pattern. This phenomenon has been studied primarily using linear grooves, post, or well patterns. We investigated the behavior of mouse embryonic fibroblasts on non-linear, sinusoidal wave grooves created via electron beam lithography on a polymethyl methacrylate (PMMA) substrate that was spin-coated onto a positively charged glass surface. Three different wave patterns, with varying wavelengths and amplitudes, and two different line patterns were created. Cell orientation and adhesion was examined after 4, 24, and 48 h after cell seeding. Attachment strength was studied via subjecting cells on substrates to centrifugal force following a 24-h incubation period. For all wave patterns studied, it was noted that cells did not reside within the groove, rather they were observed to cross over each groove, residing both inside and outside of each wave pattern, aligning linearly along the long axis of the pattern. For the linear patterns, we observed that cells tended to reside within the grooves, consistent with previous observations. The ability to add texture to a surface to manipulate cell adhesion strength and growth with only localized attachment, maintaining free space in curvilinear microtopography underlying the cell, may be a useful addition for tissue engineering and the fabrication of novel biomedical devices.
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http://dx.doi.org/10.1016/j.colsurfb.2012.11.035 | DOI Listing |
Elife
January 2025
Department of Brain Sciences, Daegu Gyeongbuk Institute of Science and Technology, Daegu, Republic of Korea.
Recent experimental studies showed that electrically coupled neural networks like in mammalian inferior olive nucleus generate synchronized rhythmic activity by the subthreshold sinusoidal-like oscillations of the membrane voltage. Understanding the basic mechanism and its implication of such phenomena in the nervous system bears fundamental importance and requires preemptively the connectome information of a given nervous system. Inspired by these necessities of developing a theoretical and computational model to this end and, however, in the absence of connectome information for the inferior olive nucleus, here we investigated interference phenomena of the subthreshold oscillations in the reference system for which the structural anatomical connectome was completely known recently.
View Article and Find Full Text PDFSensors (Basel)
December 2024
Internal Medicine, Kanai Hospital, 612-12, Yodokizu-cho, Fushimi-ku, Kyoto 613-0911, Japan.
Diabetes is known to reduce blood circulation in capillaries and arterioles; however, no devices can easily measure this on a daily basis. In this study, we developed a tool for measuring finger photoplethysmograms using green light and near-infrared LEDs. Thereafter, photoplethysmography was conducted on 25 inpatients/outpatients with diabetes and 21 adult males and females who had not been diagnosed with or treated for diabetes, hypertension, or cardiovascular disease (control group).
View Article and Find Full Text PDFMicromachines (Basel)
December 2024
School of Electro-Mechanical Engineering, Xidian University, Xi'an 710071, China.
This paper constructs a numerical simulation model for the deformation of droplets in a variable cross-section groove of a liquid droplet MEMS switch under different directions, amplitudes, frequencies, and waveforms of acceleration. The numerical simulation utilizes the level set method to monitor the deformation surface boundary of the metal droplets. The simulation outcomes manifest that when the negative impact acceleration on the -axis is 12.
View Article and Find Full Text PDFMaterials (Basel)
December 2024
Faculty of Mechanical Engineering, Lublin University of Technology, ul. Nadbystrzycka 38, 20-618 Lublin, Poland.
Recently, steel girders with sinusoidal corrugations have become increasingly popular compared to those with traditional flat webs. This paper presents the second part of the research on the application of corrugated plates with different sinusoidal profiles as webs in girders. Parametric studies have been carried out in both linear and nonlinear domains, based on a representative numerical model developed and validated by experimental results.
View Article and Find Full Text PDFBrain Sci
November 2024
Brain.Space, Tel Aviv 58855, Israel.
Background: Electroencephalogram (EEG) biomarkers with adequate sensitivity and specificity to reflect the brain's health status can become indispensable for health monitoring during prolonged missions in space. The objective of our study was to assess whether the basic features of the posterior dominant rhythm (PDR) change under microgravity conditions compared to earth-based scalp EEG recordings.
Methods: Three crew members during the 16-day AXIOM-1 mission to the International Space Station (ISS), underwent scalp EEG recordings before, during, and after the mission by means of a dry-electrode self-donning headgear designed to support long-term EEG recordings in space.
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