The Unseen Impact of Physics In Healthcare

This is a nice news article that provides a basic summary of the applications of physics in healthcare and medicine. It's another one of those where if someone thinks physics only deals with esoteric and useless ideas, show him/her this. I've mentioned many examples of similar medical/health/etc. applications and concepts that came directly from physics, such as this one.

As someone who often teaches general physics to life science/premed/bio/kinesiology major, this is definitely another useful evidence to get them to realize that the physics class they are taking has a direct relevance to their area of study.

Zz.

Three Ways You Use Quantum Physics Everyday

Most of you know this already, but it is always helpful to remind people on how quantum physics, as esoteric of a subject as it is, is the key to understanding many of the devices that we use everyday and take for granted.

The only drawback here is that the article listed only three, when there could be plenty more.

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Solid State Sensors To Detect COVID Virus?

First of all, I'm not sure why this is called "Quantum sensor". Maybe it is because it is using solid-state physics principles?

This is an interesting report, and if the simulation is valid, I'm hoping that such devices will be made real soon because it has the ability to detect other types of viruses. It really is a solid state sensor that makes use of solid state physics principles.

In the presence of viral RNA, these pairs will detach from the nanodiamond surface thanks to a process called c-DNA and virus RNA hybridization. The newly formed c-DNA-Gd³⁺/RNA compound will then freely diffuse in solution, thereby increasing the distance between the magnetic Gd and the nanodiamond. As a result of this increased distance, the NV centres will sense less magnetic “noise” and thus have a longer T₁ time, which manifests itself in a larger fluorescence intensity.

By optically monitoring the change in relaxation time using a laser-based sensor, the researchers say they could identify the presence of viral RNA in a sample and even quantify the number of RNA molecules. Indeed, according to their simulations, Cappellaro, Kohandel and colleagues, who report their work in Nano Letters, say that their technique could detect as few as a few hundred strands of viral RNA and boast an FNR of less than 1%, which is much lower than RT-PCR even without the RNA amplification step. The device could also be scaled up so that it could measure many samples at once and could detect RNA viruses other than SARS-CoV-2, they add.

I find this interesting because as students in solid-state physics, one of the first thing that the students encounter in such a course is the study of solid-state crystal lattice. This includes the type of defects in a crystal lattice, such as vacancies and impurities. So this diamond NV center is exactly those two types of defect in the lattice. Imagine that something you learned during the first couple of weeks of a course in school actually has a humongous application to human well-being!

Chalk this one up as another invaluable application from condensed matter physics.

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Combining The Best Of Both Worlds

This is a fascinating and important advancement in the physics of light sources. It seems that it has been shown experimentally how one can get the short, intense light pulses that one gets from a FEL source, and combine it with the repetition that one gets from a synchrotron light source.

Now a Sino-German team has shown that a pattern of pulses can be generated in a synchrotron radiation source that combines the advantages of both systems. The synchrotron source delivers short, intense microbunches of electrons that produce radiation pulses having a laser-like character (as with FELs), but which can also follow each other closely in sequence (as with synchrotron light sources). 

Another review of this work, from Nature where it was published, can be found here.

While this is an important step, it really is a proof-of-principle experiment, and it requires a bit more experimental work to show that this can be viable.

Although this paper represents a crucial step towards generating high-power, small-bandwidth light pulses in a particle accelerator, steady-state microbunching has not yet been demonstrated. Deng et al. have shown that, after one turn in the synchrotron, the microbunched beam can produce coherent radiation. The next challenge is to prove that this scheme can achieve such a feat over many turns. This will be difficult to accomplish experimentally for at least three reasons.

But if this can be demonstrated, a lot of things that are done at a FEL can be performed even more at an "ordinary" synchrotron light source, a facility that is a lot more plentiful.

An important point that I want to point out here is that, these are all "tools" that allow us to study things. Without these tools, we have no ability to experimentally detect, see, or measure things. It enables us to do things that we could not do before. So the advancement in science, technology, medicine, etc, depend on not only having these tools, but also the continual improvement of these tools. Advancement in science requires all of these things to occur to able to explore more difficult and complex ideas and scenarios.

This advancement in accelerator-based light source has nothing to do with high-energy physics. In fact, if you look at the type of applications that are being mentioned, there's nothing about particle physics at all!

.....on an accelerator that could extend the capabilities of these machines even further, potentially yielding applications in a next-generation chip-etching technology called extreme-ultraviolet lithography and an advanced imaging method known as angle-resolved photoemission spectroscopy.

So once again, this is my continuing attempt at trying to make people aware that "accelerators" do not automatically mean "particle collider" or "high energy physics". In fact, the majority of particle accelerators in this world are not involved in high energy physics experiments.

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Table-Top Laser Ablation Unit

I was at the Chicago's Field Museum Members Night last night. Of course, there were lots of fascinating things to see, and wonderful scientists and museum staff to talk to. But inevitably, the experimentalist in me can't stop itself from geeking out over neat gadgets.

This was one such gadget. It is, believe it or not, a table-top laser ablation unit. It is no more bigger than shoe box. I was surprised when I was told what it was, and of course, I wanted to learn more. It appears that this is still a prototype, invented by the smart folks at ETH Zurich (of course!). The scientist at Field Museum uses it to do chemical analysis on trace elements in various objects in the field, where the trace elements are just too minute in quantity that x-ray fluorescence would not be effective.

Now, you have to understand that typically, laser ablation systems tend to occupy whole rooms! It's job is to shoot laser pulses at a target, causing the evaporation of that material. The vapor then typically will migrate to a substrate where it will form a thin film, or coat another object. People use this technique often to make what is known as epitaxial films, where, if suitably chosen, the new film will have the same crystal structure as the substrate, usually up to a certain thickness.

So that was why I was fascinated to see a laser ablation kit that is incredibly small. Granted, they don't need to do lots of ablating. They only need to sample the vapor enough to do elemental analysis. The laser source is commercially bought, but the unit that is in the picture directs the laser to the target, collects the vapor, and then siphon it to a mass spectrometer or something to do its analysis. The whole thing, with the laser and the analyzer, fits on a table top, making it suitable to do remote analysis on items that can't be moved.

And of course, as always, I like to tout of the fact that many of these techniques originate out of physics research, and that eventually, they trickle down to applications elsewhere. But you already know that, don't you?

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Negative Capacitance in Ferroelectric Material Finally Found

I love this sort of reports, because it is based on a material that has been discovered for a long time and rather common, it is based on a consequence of a theory, it has both direct applications and a rich physics, and finally, it has an amazing resemblance to what many physics students have seen in textbooks.

A group of researchers have finally confirmed the existence of negative capacitance in ferroelectric material haffnium zirconium oxide Hf_0.5Zr_0.5O₂. (You may access the Nature paper here or from that news article).

Researchers led by Michael Hoffmann have now measured the double-well energy landscape in a thin layer of ferroelectric Hf_0.5Zr_0.5O₂ for the first time and so confirmed that the material indeed has negative capacitance. To do this, they first fabricated capacitors with a thin dielectric layer on top of the ferroelectric. They then applied very short voltage pulses to the electrodes of the capacitor, while measuring both the voltage and the charge on it with an oscilloscope.

“Since we already knew the capacitance of the dielectric layer from separate experiments, we were then able to calculate the polarization and electric field in the ferroelectric layer,” Hoffmann tells Physics World. “We then calculated the double-well energy landscape by integrating the electric field with respect to the polarization.”

Of course, there are plenty of potential applications for something like this.

One of the most promising applications utilising negative capacitance are electronic circuits with much lower power dissipation that could be used to build more energy efficient devices than any that are possible today, he adds. “We are working on making such devices, but it will also be very important to design further experiments to probe the negative capacitance region in the structures we made so far to help improve our understanding of the fundamental physics of ferroelectrics.”

But the most interesting part for me is that, if you look at Fig. 1 of the Nature paper, the double-well structure is something that many of us former and current physics students may have seen. I know that I remember solving this double-well problem in my graduate level QM class. Of course, we were solving it energy-versus-space dimension, instead of the energy-versus-polarization dimension as shown in the figure.

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University Research Made Your Smartphone

A lot of people are ignorant of the fact that a smartphone, or any device, for that matter, is a result of research work done by many people and organization and over a very long time. The iPhone was not solely the work of Apple. Apple benefited from all the scientific and technological progress and accumulation of knowledge to be able to produce such a device. These knowledge and progress are often done many years ago by researchers who work on a particular topic that eventually found an application in a smartphone.

I found this interesting website that highlights how research that originated out of universities under various funding agencies, resulted in the smartphone that we currently have. It lists one aspect of each of the major component of a smartphone that had it initial incubation in university research. A lot of these research work is physics-related. It is why I continue to say that physics isn't just the LHC or the Higgs or the blackhole. It is also your MRI, your iPhone, your GPS, etc...

If you need more background info on this, check out this page.

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First Human Scanned By Spectral X-Ray Scanner

Chalk this up to an application of high-energy physics in the medical diagnostic field. The first human has been scanned by a new type of x-ray scanner (registration required to read article at this moment).

The MARS scanner uses Medipix3 technology developed at CERN to produce multi-energy images with high spatial resolution and low noise. Medipix is a family of read-out chips originally developed for the Large Hadron Collider and modified for medical applications.

The Medipix3 detector measures the energy of each X-ray photon as it is detected. This spectral information is used to produce 3D images that show the individual constituents of the imaged tissue, providing significantly improved diagnostic information.

I'll repeat this, maybe to those not in the choir, that many of the esoteric experiments that you think have no relevance to your everyday lives, may turn out to be the ones that might save your lives, or the lives of your loved ones, down the road. So think about this when you talk to your elected political representatives when it comes to funding basic science.

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Graphene Might Could Kill Off Cancer Cells

Here's another example of how something that came out of physics is now finding an application in other fields, namely the medical field. Graphene, which was discovered quite a while back and won its two discoverers the Nobel Prize in Physics, has now found a possible application at fighting cancer.

It began with a theory -- scientists at the University of California knew graphene could convert light into electricity, and wondered whether that electricity had the capacity to stimulate human cells. Graphene is extremely sensitive to light (1,000 times more than traditional digital cameras and smartphones) and after experimenting with different light intensities, Alex Savchenko and his team discovered that cells could indeed be stimulated via optical graphene stimulation."

I was looking at the microscope's computer screen and I'm turning the knob for light intensity and I see the cells start beating faster," he said. "I showed that to our grad students and they were yelling and jumping and asking if they could turn the knob. We had never seen this possibility of controlling cell contraction."

The source paper can be found here, and it is open-access.

Again, this is why it is vital that funding in basic physics continues at a healthy pace. Even if you do not see the immediate application or benefit from many of these seemingly esoteric research, you just never know when any of the discovery and knowledge that are gained from such areas will turn into something that could save people's lives. We have seen such examples NUMEROUS times throughout history. Unfortunately, people are often ignorant at the origin of many of the benefits that they now take for granted.

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An Overview of CLIC at CERN

This is the lesser known effort at CERN among the general public, and yet, it may have one of the most significant impacts coming out of this high-energy physics lab.

CLIC, or the Compact Linear Collider research project at CERN has been studying accelerator science for many years. This is one of a few prominent research centers on accelerator physics throughout the world. Both they and many other accelerator research centers are making advancements in accelerator science that have a direct benefit and application to the general public.

So my intention in highlighting this article is not simply for you to learn what the people at CLIC do. Some of the description may even be beyond your understanding. What you should focus on is all the applications that are already in use, or can be possible in the near future, on the advancements made in this area of physics/engineering. These applications are not just within physics/engineering.

Unfortunately, as I've stated a few times in this blog, funding for accelerator science is often tied to funding in high energy physics, and for the US, the funding profile in this sector has been abysmal. So while accelerator science is actually independent of HEP, its funding has gone downhill with HEP funding over the last few years, especially after the shutdown of the Tevatron at Fermilab.

Whether you support funding, or increase in funding, of this area of study is a different matter, but you should at least be aware and have the knowledge of what you are supporting or not supporting, and not simply make a decision based on ignorance of what it is and what it's implication can be.

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SQUID: History and Applications

No, this is not the squid that you eat. It is the Superconducting Quantum Interference Device, which is really a very clear application of quantum mechanics via the use of superconductors.

This is a lecture presented by UC-Berkeley's John Clarke at the 2018 APS March Meeting.



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Magnon Transistors

A number of papers appear almost simultaneously on the invention of "magnon transistors". Instead of a transistor that directs the direction of electronic current flow, these are transistor that direct magnetic spin current flow, i.e. magnon flow.

Magnonic devices run exclusively on spin currents. (Spintronic devices, another electronics alternative, include both charge and spin currents.) To picture a magnon, imagine a row of spins pointing up, representing a magnetic material, and then imagine briefly flipping the spin at one end. This motion leads to a propagating wave that moves through the material as each spin influences its neighbor. Magnons can travel quickly and efficiently over long distances—up to about a centimeter in the best materials—without significantly losing energy or heating up the material, a feat not possible for electrons. But before building fast and efficient magnonic circuits, researchers need components that can regulate magnon currents.

I know I have been repeating this over and over again, but this is another example where basic research in condensed matter/solid state physics is now finding application in modern electronics.

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"Quantum Materials"

This news report highlights the discover of a semimetal known as they Weyl-Kondo semimetals. I've mentioned something similar in a previous post.

However, it should be noted that there are already a lot of material whose properties "... cannot be explained by classical physics...", and many of them are now considered to be common materials, mostly used in our modern electronics.

In fact, early on in the development of quantum mechanics, superconductivity was discovered. We now know that, as stated by Carver Mead, superconductivity is the clearest manifestation of quantum mechanics. People at that time just didn't realize it back then because they don't have the QM tools yet at their disposal.

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Muons, The Little Particles That Could

These muons are becoming the fashionable particles of the moment.

I mentioned at the beginning of this year (2017) of the use of muon tomography to image the damaged core at Fukushima. Now, muons are making headlines in two separate applications.

The first is the use of cosmic muons imaging that discovered hidden chambers inside Khufu's Pyramid at Giza. The second is more use of muons to probe the status of nuclear waste safely.

The comment I wrote in the first link still stands. We needed to know the fundamental properties of muons FIRST before we could actually use then to all these applications. And that fundamental knowledge came from high-energy/elementary particle physics.

So chalk this up to another application of such an esoteric field of study.

Zz.

How Does Proton Radiation Therapy Work?

Here's a video from Don Lincoln on a physicist's view of proton radiation therapy in attacking a tumor.



If you want a more detailed and technical information on proton therapy, you may access a more in-depth paper here. This, btw, is another example of the application of accelerator physics and elementary particle physics, in case you didn't know.

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Hot Atoms Interferometer

This work will not catch media attention because it isn't "sexy", but damn, it is astonishing nevertheless.

Quantum behavior are clearly seen at the macroscopic level because of the problem in maintaining coherence over a substantial length and time scales. One of the ways one can extend such scales is by cooling things down to extremely low temperatures so that decoherence due to thermal scattering is minimized.

So it is with great interest that I read this new paper on atoms interferometer that has been accomplished with "warm" atomic vapor[1]! You also have access to the actual paper from that link.

While the sensitivity of this technique is significantly and unsurprisingly low when compared to cold atoms, it has 2 major advantages:

However, sensitivity is not the only parameter of relevance for applications, and the new scheme offers two important advantages over cold schemes. The first is that it can acquire data at a rate of 10 kHz, in contrast to the typical 1-Hz rate of cold-atom LPAIs. The second advantage is the broader range of accelerations that can be measured with the same setup. This vapor-cell sensor remains operational over an acceleration range of 88g, several times larger than the typical range of cold LPAIs.

The large bandwidth and dynamic range of the instrument built by Biedermann and co-workers may enable applications like inertial navigation in highly vibrating environments, such as spacecraft or airplanes. What’s more, the new scheme, like all LPAIs, has an important advantage over devices like laser or electromechanical gyroscopes: it delivers acceleration measurements that are absolute, without requiring a reference signal. This opens new possibilities for drift-free inertial navigation devices that work even when signals provided by global satellite positioning systems are not available, such as in underwater navigation.

And again, let me highlight the direct and clear application of something that started out as simply appearing to be a purely academic and knowledge-driven curiosity. This really is an application of the principle of superposition in quantum mechanics, i.e. the Schrodinger Cat.

This is an amazing experimental accomplishment.

Zz.

[1] G. W. Biedermann et al., Phys. Rev. Lett. 118, 163601 (2017).

Raman Spectroscopy Used To Detect Skin Cancer

I found this piece of news while reading the Flash Physics section on Physics World. And if you've followed this blog for a while, you know that I will highlight this without any shame.

Chalk this up to another important application of something that came out of physics research and subsequently finds a usefulness in medical diagnostics. Many of us in Material Science/Condensed Matter Physics/Chemistry are aware of Raman spectroscopy techniques in the study of molecules and materials. It has been a common technique in these areas of study for many, many years since its first proposal in.... get this.... 1929![1]

So already it is a very useful technique in chemistry and material science. But now it has found another application, in medical diagnostics. It turns out that this same technique can be used to find hard-to-detect skin cancer.[2]

Abstract: Melanoma is the most deadly form of skin cancer with a yearly global incidence over 232,000 patients. Individuals with fair skin and red hair exhibit the highest risk for developing melanoma, with evidence suggesting the red/blond pigment known as pheomelanin may elevate melanoma risk through both UV radiation-dependent and -independent mechanisms. Although the ability to identify, characterize, and monitor pheomelanin within skin is vital for improving our understanding of the underlying biology of these lesions, no tools exist for real-time, in vivo detection of the pigment. Here we show that the distribution of pheomelanin in cells and tissues can be visually characterized non-destructively and noninvasively in vivo with coherent anti-Stokes Raman scattering (CARS) microscopy, a label-free vibrational imaging technique. We validated our CARS imaging strategy in vitro to in vivo with synthetic pheomelanin, isolated melanocytes, and the Mc1r^e/e, red-haired mouse model. Nests of pheomelanotic melanocytes were observed in the red-haired animals, but not in the genetically matched Mc1r^e/e; Tyr^c/c (“albino-red-haired”) mice. Importantly, samples from human amelanotic melanomas subjected to CARS imaging exhibited strong pheomelanotic signals. This is the first time, to our knowledge, that pheomelanin has been visualized and spatially localized in melanocytes, skin, and human amelanotic melanomas.

This is another example where experimental technique in physics EVENTUALLY finds applications elsewhere. I've highlighted other examples of this, with this being the most recent one before this post. Also note the "gestation" period between when this method was first proposed, and then when it became common in physics, to when it found other applications outside of its original main use. This is not new. Look at how long between when NMR became a common technique to when it evolved into MRI. Medical technology would not have evolved and advanced without a much earlier advancement in physics and physics experiments!

What I'm trying to emphasize here is that you may not feel the pain NOW when you cut funding to basic science research. But the pain WILL be felt later, by your children and grandchildren, because it takes years for what we work on now to become a useful technique elsewhere. That physics that we used to detect some esoteric particles that you don't care about may just one day be the diagnostic tool that saves someone's life!

Zz.

[1]C.V. Raman and K.S. Krishnan, The optical analog of the Compton effect, Nature 121, 711 (1928); G. Landsberg and L. Mandelstam, A novel effect of light scattering in crystals, Naturwissenschaften 16, 557 (1928); C.V. Raman and K.S. Khrishnan, The production of new radiations by light scattering, Proc. Roy. Soc. (London) 122, 23, (1929).
[2] H. Wang et al., Scientific Reports 6, Article number: 37986 (2016). Paper is open access.

Gamma-Ray Imaging At Fukushima Plant

I mentioned earlier of the muon tomography imaging that was done at the damaged reactor at Fukushima, and tried to highlight this as an example of an application that came out of high energy physics. This time a gamma-ray imaging spectroscopy was performed at the same location to pin-point contamination sites.

But as with the muon tomography case, I want to highlight an important fact that many people might miss.

To address these issues of existing methods and visualize the Cs contamination, we have developed and employed an Electron-Tracking Compton Camera (ETCC). ETCCs were originally developed to observe nuclear gammas from celestial objects in MeV astronomy, but have been applied in wider  fields, including medical imaging and environmental monitoring.

So now we have an example of a device that was first developed for astronomical observation, but has found applications elsewhere.

This is extremely important to keep in mind. Experimental physics often pushes the boundaries of technology. We need better detectors, more sensitive devices, better handling of huge amount of data very quickly, etc...etc. Hardware have to be developed to do all this, and the technology from these scientific experiments often trickle down other applications. Look at all of medical technology, which practically owes everything to physics.

This impact from physics must be repeated over and over again to the public, because a significant majority of them are ignorant of it. It is why I will continue to pick out application like this and highlight it in case it is missed.

Zz.

Imaging Fukushima Reactor Core Using Muons

If you are in the US, did you see the NOVA episode on PBS last night titled "The Nuclear Option"? If you did, did you miss, or not miss, the technique of imaging the Fukushima reactor core using the muon tomography developed at Los Alamos?

You see, whenever I see something like this, I want to shout out loud to the public on another example where our knowledge from high energy physics/elementary particle physics can produce a direct practical benefit. A lot of people still question whether our efforts in these so-called esoteric areas are worth funding. So whenever I see something like this, there should be a conscious and precise effort to point out that:

1. We had to first understand the physics of muons from our knowledge of the Standard Model of elementary particle.

2. Then those who do understand this often will start to figure out, often with collaboration of those in other areas of physics, of what could possibly be done with such knowledge.

3. And finally, they come up with a practical application of that knowledge, which originated out of an area that often produces no immediate and obvious application.

Things like this must be pointed out in SIMPLE TERMS to both the public and the politicians, because that is the only level that they can comprehend. I've pointed out previously many examples of the benefits that we get, directly or indirectly, from such field of study. It should be a requirement that any practical application should present a short "knowledge genealogy" of where the idea came from. It will be an eye-opener to many people.

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What Good Is Particle Physics?

I've tackled this issue a few times on here, such as in this blog post. In this video, Don Lincoln decides to address this issue.



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