A floating 5-µm-diameter needle-electrode on the tissue for damage-reduced chronic neuronal recording in mice

Lab on a Chip ◽  
2022 ◽  
Author(s):  
Koji Yamashita ◽  
Hirohito Sawahata ◽  
Shota Yamagiwa ◽  
Shohei Yokoyama ◽  
Rika Numano ◽  
...  

Microelectrode technology is essential in electrophysiology and has made contributions to neuroscience as well as to medical applications. However, it is necessary to minimize tissue damage associated with needle-like electrode...

Author(s):  
Naresh V. Datla ◽  
Mohammad Honarvar ◽  
Tuan M. Nguyen ◽  
Bardia Konh ◽  
Kurosh Darvish ◽  
...  

Surgical needles, for safe and accurate percutaneaous interventions, need to be navigated accurately through the tissue and placed precisely at the targets. A novel active needle, using Nitinol wires as actuators, has been proposed to navigate the needle within the tissue. In this design, when temperature of Nitinol wire was increased by Joule heating, the material undergoes a phase transformation that produces relatively large actuating forces and strains. Using both experimental and numerical simulations, the force-temperature response of the Nitinol wires were characterized. The results indicate that increasing the applied current decreases the response time to reach maximum force, but increases the maximum temperature reached. Therefore, the chosen applied current should be high enough to produce sufficient actuation force and shorter response time, but not too high such that the lower actuator temperatures are maintained to minimize tissue damage.


2021 ◽  
Vol 5 (01) ◽  
pp. 19-22
Author(s):  
Miranda Jemyma Mas'ulun ◽  
Arifa Mustika ◽  
Ema Qurnianingsih

Changes in kidney homeostasis due to diabetes can cause oxidative stress which then caused tissue damage that leads to diabetic nephropathy. Clinacanthus nutans extract is known to contain antioxidants that are reported to play an important role in the body’s defense system against oxidative stress to minimize tissue damage. This study aims to know the effect of Clinacanthus nutans leaf extract administration on kidney histopathological features of the diabetic rats model. A total of 35 rats were induced by streptozotocin which then divided into 5 groups and given Clinacanthus nutans extract with a dose of 75 mg/kgBW, 150 mg/kgBW and 300 mg/kgBW then compare with CMC-Na as control and metformin as standard drug for 14 days. The kidney histopathology was evaluated under a light microscope against the damage criteria that occurred in the proximal tubules of the kidney. As the result the least amout of kidney damage was on treatment group at dose 300 mg/kgBW, followed by extract with dose 75 mg/kgBW, 150 mg/kgBW, and metformin. In conclusion Clinacanthus nutans extract with a dose of 75 mg/kgBW, 150 mg/kgBW, and 300 mg/kgBW can improve the kidney histopathological feature of the diabetic rats model. Keywords: diabetes mellitus; histopathology; diabetic nephropathy; Clinacanthus nutans


2021 ◽  
Vol 22 (9) ◽  
pp. 4726
Author(s):  
Ashley A. Stegelmeier ◽  
Maedeh Darzianiazizi ◽  
Kiersten Hanada ◽  
Shayan Sharif ◽  
Sarah K. Wootton ◽  
...  

Interferons (IFNs) are induced by viruses and are the main regulators of the host antiviral response. They balance tissue tolerance and immune resistance against viral challenges. Like all cells in the human body, neutrophils possess the receptors for IFNs and contribute to antiviral host defense. To combat viruses, neutrophils utilize various mechanisms, such as viral sensing, neutrophil extracellular trap formation, and antigen presentation. These mechanisms have also been linked to tissue damage during viral infection and inflammation. In this review, we presented evidence that a complex cross-regulatory talk between IFNs and neutrophils initiates appropriate antiviral immune responses and regulates them to minimize tissue damage. We also explored recent exciting research elucidating the interactions between IFNs, neutrophils, and severe acute respiratory syndrome-coronavirus-2, as an example of neutrophil and IFN cross-regulatory talk. Dissecting the IFN-neutrophil paradigm is needed for well-balanced antiviral therapeutics and development of novel treatments against many major epidemic or pandemic viral infections, including the ongoing pandemic of the coronavirus disease that emerged in 2019.


2021 ◽  
Vol 118 (16) ◽  
pp. e2008233118
Author(s):  
Yuto Kita ◽  
Shuhei Tsuruhara ◽  
Hiroshi Kubo ◽  
Koji Yamashita ◽  
Yu Seikoba ◽  
...  

Microscale needle-electrode devices offer neuronal signal recording capability in brain tissue; however, using needles of smaller geometry to minimize tissue damage causes degradation of electrical properties, including high electrical impedance and low signal-to-noise ratio (SNR) recording. We overcome these limitations using a device assembly technique that uses a single needle-topped amplifier package, called STACK, within a device of ∼1 × 1 mm2. Based on silicon (Si) growth technology, a <3-µm-tip-diameter, 400-µm-length needle electrode was fabricated on a Si block as the module. The high electrical impedance characteristics of the needle electrode were improved by stacking it on the other module of the amplifier. The STACK device exhibited a voltage gain of >0.98 (−0.175 dB), enabling recording of the local field potential and action potentials from the mouse brain in vivo with an improved SNR of 6.2. Additionally, the device allowed us to use a Bluetooth module to demonstrate wireless recording of these neuronal signals; the chronic experiment was also conducted using STACK-implanted mice.


1997 ◽  
Vol 5 (3) ◽  
pp. 179-180 ◽  
Author(s):  
C Lukinuk ◽  
R Dasgupta ◽  
Jl Mahoney

Hydrofluoric (HF) acid has numerous uses both in industry and the home. HF burns are characterized by intense pain, progressive tissue damage and significant systemic effects. Pain may be prolonged because the fluoride ion remains active despite irrigation of the burn. Subcutaneous infiltration of calcium gluconate is the local treatment of choice. We present a case of hydrofluoric acid burn from rust remover that was effectively treated by topical calcium gluconate baths. A calcium gluconate solution can be prepared with material available in most hospitals and may be readily administered in this fashion. Early recognition and appropriate treatment of hydrofluoric acid burns will provide symptomatic relief and minimize tissue damage.


Author(s):  
Hilton H. Mollenhauer

Various means have been devised to preserve biological specimens for electron microscopy, the most common being chemical fixation followed by dehydration and resin impregnation. It is intuitive, and has been amply demonstrated, that these manipulations lead to aberrations of many tissue elements. This report deals with three parts of this problem: specimen dehydration, epoxy embedding resins, and electron beam-specimen interactions. However, because of limited space, only a few points can be summarized.Dehydration: Tissue damage, or at least some molecular transitions within the tissue, must occur during passage of a cell or tissue to a nonaqueous state. Most obvious, perhaps, is a loss of lipid, both that which is in the form of storage vesicles and that associated with tissue elements, particularly membranes. Loss of water during dehydration may also lead to tissue shrinkage of 5-70% (volume change) depending on the tissue and dehydrating agent.


Author(s):  
R. W. Cole ◽  
J. C. Kim

In recent years, non-human primates have become indispensable as experimental animals in many fields of biomedical research. Pharmaceutical and related industries alone use about 2000,000 primates a year. Respiratory mite infestations in lungs of old world monkeys are of particular concern because the resulting tissue damage can directly effect experimental results, especially in those studies involving the cardiopulmonary system. There has been increasing documentation of primate parasitology in the past twenty years.


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