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Millimeter waves alter DNA secondary structures and modulate the transcriptome in human fibroblasts.Biomedical Optics Express May 2022As millimetre wave (MMW) frequencies of the electromagnetic spectrum are increasingly adopted in modern technologies such as mobile communications and networking,...
As millimetre wave (MMW) frequencies of the electromagnetic spectrum are increasingly adopted in modern technologies such as mobile communications and networking, characterising the biological effects is critical in determining safe exposure levels. We study the exposure of primary human dermal fibroblasts to MMWs, finding MMWs trigger genomic and transcriptomic alterations. In particular, repeated 60 GHz, 2.6 mW cm, 46.8 J cm d MMW doses induce a unique physiological response after 2 and 4 days exposure. We show that high dose MMWs induce simultaneous non-thermal alterations to the transcriptome and DNA structural dynamics, including formation of G-quadruplex and i-motif secondary structures, but not DNA damage.
PubMed: 35774325
DOI: 10.1364/BOE.458478 -
Optics Letters Aug 2021Integrated optical antennas are key components for on-chip light detection and ranging technology (LIDAR). In order to achieve a highly collimated far field with reduced...
Integrated optical antennas are key components for on-chip light detection and ranging technology (LIDAR). In order to achieve a highly collimated far field with reduced beam divergence, antenna lengths on the order of several millimeters are required. In the high-index contrast silicon photonics platform, achieving such long antennas typically demands weakly modulated gratings with lithographic minimum feature sizes below 10 nm. Here, we experimentally demonstrate a new, to the best of our knowledge, strategy to make long antennas in silicon waveguides using a metamaterial subwavelength grating (SWG) waveguide core loaded with a lateral periodic array of radiative elements. The mode field confinement is controlled by the SWG duty cycle, and the delocalized propagating mode overlaps with the periodic perturbations. With this arrangement, weak antenna radiation strength can be achieved while maintaining a minimum feature size as large as 80 nm. Using this strategy, we experimentally demonstrate a 2-millimeter-long, single-etched subwavelength-engineered optical antenna on a conventional 220 nm SOI platform, presenting a measured far-field beam divergence of 0.1° and a wavelength scanning sensitivity of 0.13°/nm.
PubMed: 34329268
DOI: 10.1364/OL.431983 -
Annual International Conference of the... Jul 2022Breast cancer is one of the most diagnosed forms of cancer among women worldwide. However, the survival rate is very high when the tumor is diagnosed early. The search...
Breast cancer is one of the most diagnosed forms of cancer among women worldwide. However, the survival rate is very high when the tumor is diagnosed early. The search for diagnostic techniques increasingly able to detect lesions of the order of a few millimeters and to overcome the limitations of current diagnostic techniques (e.g., the X-ray mammography, currently used as standard for screening campaigns) is always active. Among the main emerging techniques, microwave and millimeter-wave imaging systems have been proposed, using either radar or tomographic approaches. In this paper, a novel dual-step millimeter-wave imaging which combines the advantages of tomographic and radar approaches is proposed. The goal of this work is to reconstruct the dielectric profile of suspicious regions by exploiting the morphological information from the radar maps as a priori information within quantitative tomographic techniques. Promising preliminary dielectric reconstruction results against simulated data are shown in both single- and dual-target scenarios, in which high-density healthy and tumor tissues are present. The reconstruction results were compared to the dielectric characteristics of human breast exvivo tissues used in the simulated models. The proposed dual-step approach allows to distinguish the nature of the targets also in the most challenging case represented by the co-presence of high-density healthy tissues and a malignant lesion, thus paving the way for a deeper investigation of this approach in experimental scenarios. Clinical Relevance-The proposed dual-step approach in the millimeter-wave regime allows to improve the reliability of the diagnostic technique, increasing its specificity.
Topics: Breast Neoplasms; Female; Humans; Mammography; Radar; Reproducibility of Results; Tomography, X-Ray Computed
PubMed: 36085729
DOI: 10.1109/EMBC48229.2022.9871999 -
AJNR. American Journal of Neuroradiology Mar 2009Aneurysms need accurate millimeters (mm). Direct millimeters were lost with digital subtraction angiography (DSA) years ago, with measurements in pixels. Advances in DSA... (Review)
Review
Aneurysms need accurate millimeters (mm). Direct millimeters were lost with digital subtraction angiography (DSA) years ago, with measurements in pixels. Advances in DSA can now give inherent millimeters. The Cerecyte aneurysm coiling trial's angiographic core lab assesses images from compact disc (CD). External fiducials for millimeter calibration are required. Of 25 cases with two 10 mm fiducials, near and far from the intensifier, the midline mean is between 9 "mm" to 15 "mm". Yet 10 mm must be 10 mm. This variance is potentially dangerous. Proprietary software seems to prohibit calibration transfer via CD to another vendor's system.
Topics: Angiography, Digital Subtraction; Calibration; Cerebral Angiography; Humans; Image Processing, Computer-Assisted; Intracranial Aneurysm; Software
PubMed: 19039047
DOI: 10.3174/ajnr.A1381 -
Science Robotics Aug 2022The limited force or torque outputs of miniature magnetic actuators constrain the locomotion performances and functionalities of magnetic millimeter-scale robots. Here,...
The limited force or torque outputs of miniature magnetic actuators constrain the locomotion performances and functionalities of magnetic millimeter-scale robots. Here, we present a magnetically actuated gearbox with a maximum size of 3 millimeters for driving wireless millirobots. The gearbox is assembled using microgears that have reference diameters down to 270 micrometers and are made of aluminum-filled epoxy resins through casting. With a magnetic disk attached to the input shaft, the gearbox can be driven by a rotating external magnetic field, which is not more than 6.8 millitesla, to produce torque of up to 0.182 millinewton meters at 40 hertz. The corresponding torque and power densities are 12.15 micronewton meters per cubic millimeter and 8.93 microwatt per cubic millimeter, respectively. The transmission efficiency of the gearbox in the air is between 25.1 and 29.2% at actuation frequencies ranging from 1 to 40 hertz, and it lowers when the gearbox is actuated in viscous liquids. This miniature gearbox can be accessed wirelessly and integrated with various functional modules to repeatedly generate large actuation forces, strains, and speeds; store energy in elastic components; and lock up mechanical linkages. These characteristics enable us to achieve a peristaltic robot that can crawl on a flat substrate or inside a tube, a jumping robot with a tunable jumping height, a clamping robot that can sample solid objects by grasping, a needle-puncture robot that can take samples from the inside of the target, and a syringe robot that can collect or release liquids.
Topics: Equipment Design; Locomotion; Needles; Robotics; Torque
PubMed: 36044558
DOI: 10.1126/scirobotics.abo4401 -
Chemical & Biomedical Imaging Dec 2023Fluorescence nanoscopy has become increasingly powerful for biomedical research, but it has historically afforded a small field-of-view (FOV) of around 50 μm × 50 μm...
Fluorescence nanoscopy has become increasingly powerful for biomedical research, but it has historically afforded a small field-of-view (FOV) of around 50 μm × 50 μm at once and more recently up to ∼200 μm × 200 μm. Efforts to further increase the FOV in fluorescence nanoscopy have thus far relied on the use of fabricated waveguide substrates, adding cost and sample constraints to the applications. Here we report PRism-Illumination and Microfluidics-Enhanced DNA-PAINT (PRIME-PAINT) for multiplexed fluorescence nanoscopy across millimeter-scale FOVs. Built upon the well-established prism-type total internal reflection microscopy, PRIME-PAINT achieves robust single-molecule localization with up to ∼520 μm × 520 μm single FOVs and 25-40 nm lateral resolutions. Through stitching, nanoscopic imaging over mm sample areas can be completed in as little as 40 min per target. An on-stage microfluidics chamber facilitates probe exchange for multiplexing and enhances image quality, particularly for formalin-fixed paraffin-embedded (FFPE) tissue sections. We demonstrate the utility of PRIME-PAINT by analyzing ∼10 caveolae structures in ∼1,000 cells and imaging entire pancreatic cancer lesions from patient tissue biopsies. By imaging from nanometers to millimeters with multiplexity and broad sample compatibility, PRIME-PAINT will be useful for building multiscale, Google-Earth-like views of biological systems.
PubMed: 38155726
DOI: 10.1021/cbmi.3c00060 -
Medical Physics 1981Two new types of thermographic instruments sensitive to millimeter-wave electromagnetic radiation have been designed, constructed, and tested. These instruments utilize... (Comparative Study)
Comparative Study
Two new types of thermographic instruments sensitive to millimeter-wave electromagnetic radiation have been designed, constructed, and tested. These instruments utilize wavelengths that are three orders of magnitude longer and much more penetrating than those used in conventional infrared thermography. The instruments are capable of detecting apparent thermal variations as small as a fraction of a degree existing at tissue depths of several millimeters below the skin. By comparison, conventional IR thermographic units are limited to sampling radiation emitted only from the surface. The millimeter wave thermographic units are designed to contribute to the clinical detection of breast abnormalities with the specific aim of accurately and noninvasively detecting breast cancer.
Topics: Adult; Breast Neoplasms; Electromagnetic Phenomena; Female; Humans; Infrared Rays; Middle Aged; Skin Temperature; Thermography
PubMed: 7322066
DOI: 10.1118/1.594991 -
Sensors (Basel, Switzerland) Mar 2020The millimeter-wave band is an ideal part of the electromagnetic radiation to diagnose human skin conditions because this radiation interacts only with tissue down to a...
The millimeter-wave band is an ideal part of the electromagnetic radiation to diagnose human skin conditions because this radiation interacts only with tissue down to a depth of a millimetre or less over the band range from 30 GHz to 300 GHz. In this paper, radiometry is used as a non-contact sensor for measuring the human skin reflectance under normal and wet skin conditions. The mean reflectance of the skin of a sample of 50 healthy participants over the (80-100) GHz band was found to be ~0.615 with a standard deviation of ~0.088, and an experimental measurement uncertainty of ±0.005. The thinner skin regions of the back of the hand, the volar forearms and the inner wrist had reflectances 0.068, 0.068 and 0.062 higher than the thicker skin regions of the palm of the hand, the dorsal forearm and the outer wrist skin. Experimental measurements of human skin reflectance in a normal and a wet state on the back of the hand and the palm of the hand regions indicated that the mean differences in the reflectance before and after the application of water were ~0.078 and ~0.152, respectively. These differences were found to be statistically significant as assessed using -tests (34 paired -tests and six independent -tests were performed to assess the significance level of the mean differences in the reflectance of the skin). Radiometric measurements in this paper show the quantitative variations in the skin reflectance between locations, sexes, and individuals. The study reveals that these variations are related to the skin thickness and water content, a capability that has the potential to allow radiometry to be used as a non-contact sensor to detect and monitor skin conditions such as eczema, psoriasis, malignancy, and burn wounds.
Topics: Adult; Electromagnetic Radiation; Equipment Design; Female; Humans; Male; Radiometry; Skin; Skin Diseases; Skin Physiological Phenomena; Upper Extremity; Water
PubMed: 32182667
DOI: 10.3390/s20051480 -
Current Biology : CB Jun 2017Plankton comprises unicellular plants - phytoplankton - and generally small (millimetres or less) animals - zooplankton - that are adrift on the currents. Phytoplankton...
Plankton comprises unicellular plants - phytoplankton - and generally small (millimetres or less) animals - zooplankton - that are adrift on the currents. Phytoplankton are responsible for about 45% of global annual primary production and are grazed by zooplankton, which in turn are suitably sized food items for predators including commercially important fish and great whales. Plankton are vital components of marine and freshwater water-column ecosystems. They also make major contributions to global biogeochemical cycling, and ameliorate atmospheric accumulation of carbon dioxide by 'pumping' carbon to the deep sea. The integrity of these roles is under threat from climate-related physiological impacts on individual organisms and on the wide-scale distribution of plankton communities.
Topics: Animals; Climate; Fishes; Food Chain; Fresh Water; Plankton; Plants; Seawater; Whales
PubMed: 28586683
DOI: 10.1016/j.cub.2017.02.045 -
Soft Robotics Apr 2024Insects and animals in nature generally have powerful muscles to guarantee their complex motion, such as crawling, running, and jumping. It is challenging for...
Insects and animals in nature generally have powerful muscles to guarantee their complex motion, such as crawling, running, and jumping. It is challenging for insect-sized robots to achieve controlled crawling and jumping within the scale of millimeters and milligrams. This article proposes a novelty bionic muscle actuator, where an electrical pulse is applied to generate joule heat to expand the actuator's chamber. Under the restoring force of the spring element, the chamber contracts back to the initial state to finish a complete cycle. The actuator can obtain high-frequency vibration under the high-frequency electrical signal. We propose a microrobot based on the novelty actuator to achieve controlled crawling and jumping over the obstacle of the millimeter-sized robot. The robot is fabricated with two actuators as a crawling module and one actuator as a jumping module, with a mass of 52 mg, length of 9.3 mm, width of 9.1 mm, and height of 4 mm. The microrobot has a maximum crawling turning velocity of 0.73 rad/s, a maximum jump height of 42 mm (10.5 times body height), and a maximum jump velocity of 0.91 m/s. This study extends the potential for applying the novelty bionic-muscle actuator to the microrobot.
PubMed: 38190294
DOI: 10.1089/soro.2023.0025