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Devices that bypass the hair cells in the inner ear and directly stimulate the auditory nerve are called cochlear implants. Cochlear implants are used to treat deafness caused by the loss of hair cells in the cochlea. The hair cells are the sensory cells that convert sound vibrations into electric neural signals (Purves et al., 2001). With state-of-the-art ...


8

Nice question. I must say it took me many hours to get satisfactory answer. Hairs are made of keratin molecules, which contain cysteine. Cysteine has thiol (-SH) group, by which it can form disulfide (-S-S-) bond with another cysteine of another keratin, causing bending of hair. See this image from here: Curling of hair can be justified on both microscopic ...


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As @AliceD mentioned, cochlear implant is one of the earliest achievements of neural engineering. However, there are orders of magnitude more inner hair cells (IHC) and even more auditory nerve fibers (AN) in human cochlear than the current cochlear implants offer electrodes. If you are interested in a more detailed model of IHC to AN signal transmission, ...


6

Interesting question! You ask 3 questions if I am correct: What is tDCS; What are the adverse effects of tDCS (at 0.1 - 2 mA); What are the health benefits (enhanced focus); I will answer your questions one by one: (1) What is tDCS: tDCS devices are TransCranial Direct Current Stimulation (tDCS) devices. They send direct current through (trans) the ...


5

No, there is no safe place. Devices in contact with blood are subject to thrombosis and embolism. Even devices designed for bio/hemocompatibility are not 100% safe: they are used because the illnesses and diseases they treat are more dangerous than the side effects. Immune responses and platelet activation that occur in the vicinity of a device could also ...


5

It gets diffused out, like you expected. Grist (2013) writes about this in relation to "the bends," which has already been mentioned by user1136. He writes: Cavitation of blood containing normal oxygen and nitrogen levels by mechanical heart valves after implantation generates bubbles that can be detected in the brain using transcranial Doppler ...


5

In a PNAS paper by Palti's group (2007) they explain the hypothesis behind the technique: They reason alternating currents of 100 kHz to 1 MHz specifically affects dividing cells and thereby targets cancer cells. Note that this is the same basic idea as chemotherapy and radiotherapy, which also target dividing cells mostly. The mechanism of action of ...


4

The problem of off-targets in CRISPR/Cas is often discussed. It was shown that the system allows mismatches up to five basepairs. For your question, if it is helpful to elongate the gRNA: it was shown that truncating the RNA enhances the specificity more than elongating (see also here). So what can we do? Well, there are different methods to improve the ...


2

The question you are asking is an ethical problem rather than a biological one. This particular nature article highlights the problem I am speaking about. In brief, children afflicted with SCID were subjected to what at the time was termed as a pioneering retroviral treatment. The idea being you replace the defective gene with the real one, in case of the ...


1

Biologically, the notion of a "perfect predator" isn't well-defined, because it isn't clear what is being perfected. Predators are just organisms that eat other organisms. What would it mean to be "perfect" at being a predator? Would it mean: Fastest possible at chasing its prey? But it just needs to be faster than the prey, if it even ...


1

I think biomedical applications are not an absurd perspective. More specifically, regarding your concerns: (1) Unless the DNA is first internalized by cells, and then somehow enters the nucleus (both are not very likely, especially considering the small concentrations we're talking about here after dilution in a human body), you would still need the DNA ...


1

I believe the best place for this sort of implant would be the femoral vein in the upper leg. It's one of the larger blood vessels, and on the return trip so you don't have to be as concerned about oxygen removal from the blood on whatever apparatus you have. You're far away from all non-peripheral organs as well. I would also question whether such an ...


1

PDMS in fact is established to be a reliable material for cell culture in many microfluidic devices. Here are several papers (Titles) including reviews on microfluidic devices using PDMS: Microfluidic devices for cell cultivation and proliferation Here Adhesion patterns in the microvasculature are dependent on bifurcation angle Here (Microvascular Research)...


1

The number of antibiotics that remain undiscovered is huge, but is estimated to be tens of thousands of compounds. The number of bacteria that remain undiscovered is also huge, but is estimated to be perhaps millions of species. Resistance to antibiotics is developed by bacteria in response to other bacteria and human antibiotic use, but in theory all ...


1

I believe you're referring to this 2013 announcement from King's College, Biological tooth replacement -- a step closer. So called "BioTeeth" are sought after because Current implant-based methods of whole tooth replacement fail to reproduce a natural root structure and as a consequence of the friction from eating and other jaw movement, loss of jaw bone ...


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