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  • richardmitnick 10:43 pm on June 6, 2017 Permalink | Reply
    Tags: , Index of refraction, Nanometric disorder, , , Sensing the Nanoscale with Visible Light, Technion, Wave localization   

    From Technion: “Sensing the Nanoscale with Visible Light” 

    Technion bloc

    Israel Institute of Technology

    06/06/2017
    No writer credit found

    1
    (Comparison) – scale of magnitude: two nearly-identical structures and a Flu virus.

    Sensing the nanoscale with visible light, and the fundamentals of disordered waves

    A general rule in optics is that light is insensitive to features which are much smaller than the optical wavelength. In fact, the whole concept of “index of refraction” arises from the fact that light experiences a medium as a whole, not responding to the individual atoms. However, a new experiment at the Technion-Israel Institute of Technology shows that even features that are more than 100 times smaller than the wavelength can still be sensed by light.

    Published last Thursday in Science, the work – conducted by Hanan Herzig Sheinfux and Dr. Yaakov Lumer from the group of Distinguished Professor Mordechai (Moti) Segev from the Technion, in collaboration with Dr. Guy Ankonina and Prof. Guy Bartal (Technion), and Prof. Azriel Genack (City University of New York), examines a stack of nanometrically thin layers – each layer is on average 20,000 times thinner than a sheet of paper. The exact thickness of the layers is purposely random. Ordinarily, this nanometric disorder should bear no physical importance: light just experiences the average properties, as if this were a homogeneous medium. But, in this experiment, a 2nm (~6 atoms) thickness increase to one single layer somewhere inside the structure is enough to change the amount of light reflected at a specific angle of incidence. Furthermore, the combined effect of all the random variations in all the layers manifests an important physical phenomenon called Anderson localization, but in a regime where it was believed to have vanishingly small effects.

    Wave localization was first discovered in 1958 by Philip W. Anderson, who was awarded the Nobel Prize for it in 1977. Anderson localization is a notoriously difficult effect to demonstrate in the lab. In particular, when the random features of a sample are much smaller than the wavelength, Anderson localization has practically no effect. Indeed, the random arrangement of the atoms in a material such as glass is not observable with visible light: the glass looks completely homogeneous, even under the best optical microscope. But the localization effect seen in this recent experiment is surprisingly potent.

    How is this possible? Imagine being pushed by a mosquito. Normally, mosquitos are too weak to push anything as heavy as a grown person. However, if you happen to be walking on a tightrope, even a relatively small shove can have a large effect – all the other forces are balanced and the effect of the mosquito is still effectively amplified (technically, a mosquito’s shove is so weak, that this amplification would likely be ineffective, but the principle remains). In a crude analogue, while nanometric disorder is very weak, this experiment was conducted near the threshold of total internal reflection – a point of fragile stability, analogous to standing on the tight-rope – and the influence of disorder was effectively amplified.

    These findings are a proof-of-concept which may pave the way for major new applications in sensing. This approach may allow the use of optical methods to make measurements of nanometric defects in computer chips and photonic devices. Since such an optical approach is expected to be faster and less expensive than measurements using electrons or X-rays, these results have a significant potential impact for manufacturing technology and basic science.

    See the full article here .

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    dedicated to the creation of knowledge and the development of human capital and leadership,
    for the advancement of the State of Israel and all humanity.

     
  • richardmitnick 4:39 pm on June 4, 2017 Permalink | Reply
    Tags: , Angle of incidence, , CUNY, Discovery of electron localization in 1958, Disorder turns a system from a conductor to an insulator, Features that are even 100 times smaller than the wavelength can still be sensed by light, , , Science Daily, Sensing the nanoscale with visible light and the fundamentals of disordered waves, Technion   

    From Technion via Science Daily: “Sensing the nanoscale with visible light, and the fundamentals of disordered waves” 

    Technion bloc

    Technion

    1

    Science Daily

    2
    The multilayer stack is grown on a prism and covered with an absorbing Pt layer. A laser beam is incident at angle q on the prism, and the output reflection is measured by a charge-coupled device. Credit: Azriel Genack

    June 1, 2017
    No writer credit found

    We cannot see atoms with the naked eye because they are so small relative to the wavelength of light. This is an instance of a general rule in optics — light is insensitive to features which are much smaller than the optical wavelength. However, a new experiment appearing in Science shows that features that are even 100 times smaller than the wavelength can still be sensed by light.

    Features that are even 100 times smaller than the wavelength can still be sensed by light, a new experiment shows.

    Hanan Sheinfux and Dr. Yaakov Lumer, from the group of Prof. Moti Segev at the Technion -Technical Institute of Israel, carried out this study in collaboration with Dr. Guy Ankonina and Prof. Guy Bartal (Technion) and Prof. Azriel Genack (City University of New York).

    Their work examines a stack of nanometrically thin layers — each layer is on average 20,000 times thinner than a sheet of paper. The exact thickness of the layers is purposely random, and ordinarily this nanometric disorder should bear no physical importance. But this experiment shows that even a 2nm (~6 atoms) thickness increase to one single layer somewhere inside the structure can be sensed if light illuminates the structure at a very specific angle of incidence. Furthermore, the combined effect of all the random variations in all of the layers manifests an important physical phenomenon called Anderson localization, but in a regime where it was believed to have vanishingly small effects.

    “This work demonstrates that light can be trapped in structures much thinner than the wavelength of light and that minute changes in this structure are observable,” said Dr. Genack. “This makes the structure highly sensitive to the environment.”

    The discovery of electron localization in 1958, for which Anderson was awarded the Nobel Prize in 1977, is the phenomenon where disorder turns a system from a conductor to an insulator. The phenomenon has been shown to be a general wave phenomenon and to apply to light and sound as well as to electrons. Anderson localization is a notoriously difficult effect to demonstrate in the lab. Generally, localization has practically no effect when random features of a sample are much smaller than the wavelength. Indeed, the random arrangement of the atoms in a disordered medium such as glass is not observable with visible light: the glass looks completely homogeneous, even under the best optical microscope. However, the localization effect seen in this recent experiment is surprisingly potent.

    As a crude analogue to the physics enabling these results, try speaking to a friend in the same room with a loud engine. One way to be heard is to raise your voice above the sound of the engine. But it might also be possible to speak if you can find a quiet spot in the noise, where the engine’s sound is relatively weak. The engine’s sound is analogue to the “average” influence of the layers and raising your voice is the same as using “strong” disorder with wavelength-sized components. However, this experiment has demonstrated such structures exhibit an “exceptional point” which is equivalent to the quiet spot in the room. It is a point where, even if the disorder is weak (nanometric), the average effect of the structure is even weaker. The parts of the experiment performed in the vicinity of this point therefore show an enhanced sensitivity to disorder and exhibit Anderson localization.

    These findings are a proof-of-concept which may pave the way for major new applications in sensing. This approach may allow the use of optical methods to make high-speed measurements of nanometric defects in computer chips and photonic devices.

    See the full article here .

    Please help promote STEM in your local schools.

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    Technion Campus

    A science and technology research university, among the world’s top ten,
    dedicated to the creation of knowledge and the development of human capital and leadership,
    for the advancement of the State of Israel and all humanity.

     
  • richardmitnick 7:35 pm on August 15, 2016 Permalink | Reply
    Tags: , , Technion   

    From Technion: “Technion Scientist is First to Observe Hawking Radiation” 

    Technion bloc

    Technion

    August 15, 2016
    Kevin Hattori

    The eminent British scientist Stephen Hawking made predictions, 42 years ago, about elusive radiation emanating from black holes.

    Known as Hawking radiation, this phenomenon is too weak to observe with current techniques, and remained a “holy grail” for the fields of atomic physics, nonlinear optics, solid state physics, condensed matter superfluids, astrophysics, cosmology, and particle physics. It remained as such until Prof. Jeff Steinhauer’s observations of Hawking radiation in an analogue (model) black hole created at his Atomic Physics Lab in the Technion-Israel institute of Technology Faculty of Physics.

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    Technion-Israel Institute of Technology Professor Jeff Steinhauer

    Steinhauer’s latest findings, published today in Nature Physics, describe the first observation of thermal, quantum Hawking radiation in any system. “We observe a thermal distribution of Hawking radiation, stimulated by quantum vacuum fluctuations, emanating from an analogue black hole,” says Steinhauer. “This confirms Hawking’s prediction regarding black hole thermodynamics.”

    Pairs of phonons (particles of sound) appear spontaneously in the void at the event horizon (in layman’s terms, this is “the point of no return” in spacetime, beyond which events cannot affect an outside observer) of the analogue black hole. One of the phonons travels away from the black hole as Hawking radiation, and the other partner phonon falls into the black hole. The pairs have a broad spectrum of energies. It is the correlations between these pairs that allow for the detection of the Hawking radiation.

    The Hawking and partner particles within a pair can have a quantum connection called “entanglement.” Steinhauer explains: “Using a technique we developed, we saw that high energy pairs were entangled, while low energy pairs were not. This entanglement verifies an important element in the discussion of the information paradox (the idea that information that falls into a black hole is destroyed or lost) as well as the firewall controversy (the theory that a wall of fire – resulting from the breaking of the entanglement between the Hawking particles and their partners – exists at the event horizon of a black hole).”

    This observation of Hawking radiation, performed in a Bose-Einstein condensate (a quantum state of matter where a clump of super-cold atoms behaves like a single atom), verifies Hawking’s semiclassical calculation, which is viewed as a milestone in the quest for quantum gravity. The observation of its entanglement verifies important elements in the discussion of information loss in a real black hole.

    Steinhauer has been working exclusively on the proof since 2009 in his hand-assembled lab, replete with lasers and dozens of mirrors, lenses, and magnetic coils to simulate a black hole. Motivated by an overriding curiosity regarding the laws of physics since he was a child, Steinhauer says that evidence for the existence of quantum Hawking radiation brings us one step further in our endless journey of discovering the laws of the universe. This understanding itself is important to human beings, as is the applications of the laws of physics in society.

    Through the Wormhole, a Science Channel TV show hosted and narrated by Academy Award winner Morgan Freeman, featured Steinhauer back in 2012. Here, he discussed his creation of an analogue black hole in the lab and his hopes of using it to observe Hawking radiation. The analogue black hole takes advantage of his pioneering ultra-high resolution imaging system.

    In 2014, Steinhauer succeeded in doing this, publishing his results in a top science journal of the first observation of Hawking radiation in any system. This earlier work demonstrated self-amplifying Hawking radiation, which reflected from the inner horizon, returned to the outer horizon, and caused additional Hawking radiation. In contrast, his latest research endorses the existence of quantum Hawking radiation, the spontaneous appearance of Hawking pairs.

    See the full article here .

    Please help promote STEM in your local schools.

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    Technion Campus

    A science and technology research university, among the world’s top ten,
    dedicated to the creation of knowledge and the development of human capital and leadership,
    for the advancement of the State of Israel and all humanity.

     
  • richardmitnick 3:12 pm on August 2, 2016 Permalink | Reply
    Tags: , , Innovative oral targeted treatment for gastric tumors, , Technion   

    From Technion via Israel 21c: “A new nanotech approach for treating stomach cancer” 

    Technion bloc

    Technion

    1`

    Israel 21c

    July 27, 2016
    Abigail Klein Leichman

    Israeli study introduces innovative oral targeted treatment for gastric tumors.

    A potential oral nanomedicine treatment for stomach cancer has been developed at the Technion-Israel Institute of Technology using a combination of anti-cancer drugs and a chemo-resistance reversal agent, which eliminates gastric tumors’ resistance to chemotherapy drugs.

    The treatment could be self-administered at home by the patient — eliminating the need for hospitalization, which is dangerous for immunocompromised cancer patients due to drug-resistant pathogens widespread in hospitals.

    The new treatment modality is based on a transport platform developed as part of Maya Bar-Zeev’s doctoral dissertation at the Russell Berrie Nanotechnology Institute, under the joint supervision of Prof. Yoav Livney of the Faculty of Biotechnology Engineering, and Prof. Yehuda Assaraf, Dean of the Faculty of Biology and Director of the Fred Wyszkowski Cancer Research Laboratory at the Technion.

    Their study proving the effectiveness of this regimen was published in the journal Oncotarget, earlier this year.

    The unique transport platform packages the drugs in beta-casein. Caseins are the main proteins found in milk, in structures called micelles. The natural role of casein micelles is the transfer of calcium, phosphorus and protein from mother to baby through breast milk. Beta-casein’s spatial structure allows it to encapsulate substances that are not water-soluble.

    Previous studies in Livney’s lab first presented the potential of casein micelles for oral delivery of vitamins and drugs. A series of joint studies carried out with Assaraf examined beta-casein as a nanometric delivery vehicle for anti-cancer chemotherapy drugs.

    Since this platform effectively carries the drug to the stomach and releases it there for easy digestion, the researchers believe that it will be particularly effective in gastric diseases and gastric cancer in particular — one of the most aggressive and deadly types of cancer.

    Following a series of successful laboratory experiments that proved the system’s effectiveness in drug-resistant human gastric cancer cells, the research group will next experiment on lab animals.

    Their expectation is that the nanometric platform will achieve a dramatic improvement in the treatment of stomach cancer, including in cells that have developed resistance to a broad spectrum of anti-cancer drugs.

    See the full article here .

    Please help promote STEM in your local schools.

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    Technion Campus

    A science and technology research university, among the world’s top ten,
    dedicated to the creation of knowledge and the development of human capital and leadership,
    for the advancement of the State of Israel and all humanity.

     
  • richardmitnick 7:08 pm on July 31, 2016 Permalink | Reply
    Tags: , Carbon nanotubes, Technion   

    From Technion: “Watch Out, Silicon Chips. Molecular Electronics Are Coming” 

    Technion bloc

    Technion

    July 11, 2016 [Just now in social media by American Technion Society]
    Kevin Hattori

    Technion breakthrough could replace silicon chips in the world of electronics

    Technion researchers have developed a method for growing carbon nanotubes that could lead to the day when molecular electronics replace the ubiquitous silicon chip as the building block of electronics. The findings are published this week in Nature Communications.

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    Professor Yuval Yaish

    Carbon nanotubes (CNTs) have long fascinated scientists because of their unprecedented electrical, optical, thermal and mechanical properties, and chemical sensitivity. But significant challenges remain before CNTs can be implemented on a wide scale, including the need to produce them in specific locations on a smooth substrate, in conditions that will lead to the formation of a circuit around them.

    Led by Prof. Yuval Yaish of the Viterbi Faculty of Electrical Engineering and the Zisapel Nanoelectronics Center at the Technion, the researchers have developed a technology that addresses these challenges. Their breakthrough also makes it possible to study the dynamic properties of CNTs, including acceleration, resonance (vibration), and the transition from softness to hardness.

    The method could serve as an applicable platform for the integration of nano-electronics with silicon technologies, and possibly even the replacement of these technologies in molecular electronics.

    “The CNT is an amazing and very strong building block with remarkable electrical, mechanical and optical properties,” said Prof. Yaish. “Some are conductors, and some are semiconductors, which is why they are considered a future replacement for silicon. But current methods for the production of CNTs are slow, costly, and imprecise. As such, they generally cannot be implemented in industry.”

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    Preferential adsorption of p-nitrobenzoic acid on carbon nanotubes. (a) Top: Chemical structure of p-nitrobenzoic acid (pNBA). Bottom: Schematic illustration of the monoclinic unit cell of pNBA powder as extracted from X-ray diffraction analysis. (b,c) Dark field optical microscopy images of pNBA nanocrystals adsorbed along CVD grown carbon nanotubes (CNTs). Scale bar, 50 and 20 µm, respectively. (d) Amplitude image of AFM of a single CNT with a few pNBA nanocrystals along. Scale bar, 1 µm. Inset: height cross sections along the marked lines of the main figure. (e) Dark field optical microscopy image of pNBA nanocrystals after intensive deposition. Note the black voids along the CNT. Scale bar, 20 µm. (f) Dark field optical microscopy image of pNBA nanocrystals adsorb onto commercial dispersed CNTs. Scale bar, 20 µm. No image credit.

    Due to the nanometer size of the CNTs (100,000 times smaller in diameter than the thickness of a human hair) it is extremely difficult to find or locate them at specific locations. Prof. Yaish, and graduate students Gilad Zeevi and Michael Shlafman, developed a simple, rapid, non-invasive and scalable technique that enables optical imaging of CNTs. Instead of depending upon the CNT chemical properties to bind marker molecules, the researchers relied on the fact that the CNT is both a chemical and physical defect on the otherwise flat and uniform surface. It can serve as a seed for the nucleation and growth of small, but optically visible nanocrystals, which can be seen and studied using a conventional optical microscope (CNTs, because of their small size, are too small to be seen in this way). Since the CNT surface is not used to bind the molecules, they can be removed completely after imaging, leaving the surface intact, and preserving the CNT’s electrical and mechanical properties.

    “Our approach is the opposite of the norm,” he continued. “We grow the CNTs directly, and with the aid of the organic crystals that coat them, we can see them under a microscope very quickly. Then image identification software finds and produces the device (transistor). This is the strategy. The goal is to integrate CNTs in an integrated circuit of miniaturized electronic components (mainly transistors) on a single chip (VLSI). These could one day serve as a replacement for silicon electronics.”

    Prof. Yaish also noted that the ability to demonstrate this principle and create world-class devices was made possible by the unique infrastructures available at the Technion clean room facilities in the Wolfson Microelectronics Center, headed by Prof. Nir Tessler.

    See the full article here .

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    dedicated to the creation of knowledge and the development of human capital and leadership,
    for the advancement of the State of Israel and all humanity.

     
  • richardmitnick 2:49 pm on July 31, 2016 Permalink | Reply
    Tags: , , , Technion   

    From Technion: “Lethal Sequences” 

    Technion bloc

    Technion

    31/07/2016
    No writer credit found

    1
    Underrepresented sequences (URSs) inhibit protein translation and can be lethal. Top, The genetic information is transferred to the protein synthesis machine, the ribosome, by messenger RNA. Amino acids (colored circles) are added one by one and the newly synthesized protein is pushed out of the ribosome. On the left is a normal sequence. On the right is a sequence with the strong URS – CMYW, which slows translation and prevents ribosome recycling. Middle, left, proteins fold and assemble correctly. On the right, fewer full-length proteins are produced and truncated proteins are also produced due to the URS effect on the ribosome. Bottom, E. coli cells grown on plates in the absence (-) or presence (+) of the protein translation signal molecule IPTG. On the left, cells grow normally with or without IPTG. On the right, cells grow normally when the URS containing protein is not synthesized (no IPTG). When IPTG is added, the URS containing protein synthesis is initiated (+), ribosomes are inhibited, and fewer colonies of the bacteria grow. No image credit

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    Prof. Noam Adir, Dean of the Schulich Faculty of Chemistry.

    A study from the lab of Prof. Noam Adir of the Schulich Faculty of Chemistry at Technion – Israel Institute of Technology: natural evolutionary processes prevent the presence of dangerous and potentially lethal molecular interactions by avoiding the presence of specific protein sequences in microorganisms. They found these sequences by a novel method – looking for what is missing in biological data sets. The group then experimentally showed that when these sequences are present in a protein, bacterial growth is indeed inhibited. The study was recently published in the Proceedings of the National Academy of Sciences, USA.

    Evolution is an ongoing process, whereby those individuals of species that are the most fit for their environment have more offspring and thus out-compete less fit individuals. The individual’s fitness is a product of the quality of its cellular biochemistry, made possible by the thousands of enzymes that allow its physiology to perform all of the necessary chemical reactions that allow the cell to live. Deficiency in these molecular functions can lead to disease, loss of adaptability to environmental changes, or weakness against other organisms. The molecular machines that make life possible are large polymers made up of linear sequences of building blocks that contain different chemical functions: proteins, DNA, and RNA. Biological variety is a result of the evolutionary changes in these polymers, first and foremost the result of the astronomic number of possible permutations in the order of the 20 naturally occurring amino acid (AA) residues that are the building blocks of proteins. There are 8,000 possible sequences of three AAs, 160,000 sequences of four AAs, over 3 million sequences of five AAs and so on. Since proteins can contain between hundreds to thousands of AAs, the possibilities are endless.

    The millions of different protein sequences found in all organisms determine the three-dimensional structures that give proteins the ability to function correctly. Proteins in cells can work alone or associate correctly with other cellular components, while avoiding incorrect and harmful associations with other components. Changes to the sequences naturally occur due to mutations (single site, or larger changes due to more dramatic sequence shuffling) of an organism’s DNA – the genetic material. Changes due to mutations can lead to new positive characteristics, or they may have negative consequences to the organism’s viability. A mutation that has a negative effect may prevent the organism from competing with other organisms in its environment, eventually leading to its demise. One could predict that over time, evolutionary pressure would work against the presence of organisms containing these internally lethal sequences and they would disappear.

    Over the past few years, there has been a world-wide effort to obtain the entire DNA sequences (the entire genomes) of many organisms. These data have given us the ability to predict all of the possible protein sequences (the proteome) that might exist in organisms as simple as bacteria or as complicated as humans. Prof. Adir and his students, Dr. Sharon Penias-Navon and Ms. Tali Schwartzman, hypothesized that the huge amount of data made available by modern genomics would allow them to look for short sequences that occur less often than expected or are completely missing in the organism’s proteome. They developed a computer program that searched the many existing data sets to identify short sequences that are underrepresented (URSs). While they found that most of the sequences of three or four AAs indeed do exist at their expected frequency in the proteins of different organisms, URSs do exist. They used the program to search for URSs in the proteomes of many different organisms (especially pathogenic microorganisms) and found that different organisms have different URSs. Adir and Penias-Navon wanted to prove that these URSs are indeed harmful, and they hypothesized that protein synthesis (translation) by the ribosome is the function that URSs might harm.

    They embedded bacterial URSs (identified in the proteome of the gut bacterium E. coli) comprised of three or four AAs in a normal protein sequence, and showed that no matter where they put the URS, protein translation was inhibited. They showed that these same E. coli URSs had no effect on protein translation in human cells, showing that the effect is species specific. They further showed that one four-AA URS was powerful enough to inhibit translation completely to the point where the growth of the bacterial cells was significantly reduced: these are indeed lethal sequences. Adir and Navon suggested that URSs could be used as highly specific anti-microbial agents, and a patent, together with the Technion, was submitted.

    In order to obtain even more precise molecular details on the action of the URS, they initiated a collaboration with Prof. Joseph Puglisi and his student Dr. Guy Kornberg of Stanford University, who are experts in following protein translation in single ribosomes, thereby obtaining direct information on the translation reaction mechanism. Using these single molecule methods, the inhibitory effect of the existence of a URS on translation was confirmed. Their methods enabled a precise determination of the site of inhibition. They found that as soon as the URS AAs enter the entrance to the ribosomal nascent protein exit tunnel, translation is inhibited.

    See the full article here .

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    Technion Campus

    A science and technology research university, among the world’s top ten,
    dedicated to the creation of knowledge and the development of human capital and leadership,
    for the advancement of the State of Israel and all humanity.

     
  • richardmitnick 6:29 am on July 15, 2016 Permalink | Reply
    Tags: , Noninvasive brain stimulation through ultrasound, Technion   

    From Technion via Israel 21c: “Noninvasive brain stimulation through ultrasound” 

    Technion bloc

    Technion

    1
    Israel 21c

    July 10, 2016
    Abigail Klein Leichman

    Israelis reveal a mechanism for accurate and individualized control of brain activity using ultrasonic waves.

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    Image via Shutterstock.com

    Accurate and noninvasive artificial brain stimulation is one of the holy grails for neuroscientists looking to advance brain research and treatment.

    Ultrasonic neuromodulation – exciting the neurons using ultrasound waves – shows great promise as a way to complement or even replace treatments that require risky surgical insertion of electrodes through the skull.

    Researchers from the Russell Berrie Nanotechnology Institute at Technion-Israel Institute of Technology in Haifa have added critical new insights to the understanding of the mechanisms that enable ultrasonic neuromodulation to activate and suppress brain cells.

    In a study just published in the journal eNeuro, professors Shy Shoham and Eitan Kimmel and PhD student Misha Plaksin reveal that the ultrasound’s waveform pattern dramatically affects its interaction with neurons, and consequently certain ultrasound patterns have a different effect on different types of neurons.

    This understanding makes it possible to predict the outcome of complex interactions in realistic brain neural networks and to improve the use of ultrasonic neuromodulation in the noninvasive medical treatment of neurological diseases.

    “Right now, the brain is still something of a closed box,” said Shoham. “Ultrasound could help to pry open that box.”

    “Now, for example, for the first time at the Technion and in cooperation with InSightec [a pioneer in using ultrasound beams instead of scalpels] and Prof. Itamar Kahn of the Technion’s Rappaport Faculty of Medicine, we are using functional MRI technology to examine the effect of ultrasound on brain activity, so that we can both excite and monitor it without recourse to electrodes and other invasive means.”

    See the full article here .

    Please help promote STEM in your local schools.

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    Technion Campus

    A science and technology research university, among the world’s top ten,
    dedicated to the creation of knowledge and the development of human capital and leadership,
    for the advancement of the State of Israel and all humanity.

     
  • richardmitnick 7:57 am on July 14, 2016 Permalink | Reply
    Tags: , , Placebos physically boost immunity Israeli study shows, Technion   

    From Technion: “Placebos physically boost immunity, Israeli study shows” 

    Technion bloc

    Technion

    July 5, 2016
    Marlowe Hood

    Technion researchers find stimulating brain’s feel-good center in mice creates cells twice as effective in killing bacteria

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    A lab mouse. (photo credit: Flash90)

    Artificially stimulating the brain’s feel-good center boosts immunity in mice in a way that could help explain the power of placebos, a study reported Monday.

    “Our findings indicate that activation of areas of the brain associated with positive expectations can affect how the body copes with diseases,” said senior author Asya Rolls, an assistant professor at the Technion-Israel Institute of Technology’s Faculty of Medicine.

    The findings, reported in Nature Medicine, “might one day lead to the development of new drugs that utilize the brain’s potential to cure,” she said.

    It has long been known that the human brain’s reward system, which mediates pleasure, can be activated with a dummy pill devoid of any active ingredients — known as a placebo — if the person taking it thinks it’s real medicine.

    “But it was not clear whether this could impact physical well-being,” Rolls told AFP.

    Nor did scientists know — if, indeed, an immune response was strengthened — exactly how the signal travelled through the body.

    Rolls and colleagues incubated immune cells from mice exposed to deadly E. coli bacteria after specific cells in the animals’ reward centre had been stimulated.

    These immune cells were at least twice as effective in killing bacteria than ordinary ones, they reported.

    In a second test, the scientists vaccinated different mice with the same immune cells.

    Thirty days later, the new set of rodents was likewise twice as likely to be able to fight off infection.

    The immune-boosting information emanated from a part of the brain called the ventral tegmental area, home to a reward system powered by the mood-modifying chemical dopamine.

    This area lights up in brain scans when a mouse — or a human — knows that a tasty meal, or a sexual encounter, is in the offing.

    From there, the study found, the message is routed via the sympathetic nervous system, which is responsible for snap responses in a crisis situation, until it triggers the bacteria-fighting immune response.

    Evolutionary pressures may play a key role in the observed association, the researchers speculated.

    “Feeding and sex expose one to bacteria,” explained Rolls said.

    “It would give one an evolutionary advantage if — when the reward system is activated — immunity is also boosted.”

    The next step will be mice experiments to find molecules — potential drugs — that could reproduce this cause-and-effect.

    “Maybe they could be used as new therapeutic targets,” Rolls said.

    The breakthrough was made possible thanks to a pair of new technologies, said the study’s other lead author, Shai Shen-Orr, also from the Technion-Israel Institute of Technology.

    One enables neurons to be switched on an off. The second gives scientists high-resolution profiles of hundreds of thousands of cells in the immune system.

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    Technion Campus

    A science and technology research university, among the world’s top ten,
    dedicated to the creation of knowledge and the development of human capital and leadership,
    for the advancement of the State of Israel and all humanity.

     
  • richardmitnick 5:13 am on July 13, 2016 Permalink | Reply
    Tags: , Technion, Technology for Tissue Graft Success   

    From Technion: “Technology for Tissue Graft Success” 

    Technion bloc

    Technion

    July 13, 2016
    Georgi

    1
    No image caption. No image credit.

    Technion breakthrough improves chances tissue grafts will survive and thrive

    A better understanding of the effect of mechanical forces on blood vessel assembly in engineered tissues aids optimal growth of new blood vessels after tissue transplantation.

    Researchers from the Technion-Israel Institute of Technology and colleagues in the U.S. have developed technology to tailor grafted tissues that can respond to certain natural forces affecting blood vessels. The researchers also found that matching the structure of the engineered vessels to the structure of the host tissues at the site of implantation helps the tissue implant integration, improving the chances that grafted tissues will survive better. The findings were published recently in The Proceedings of the National Academy of Sciences (PNAS).

    “Developing functional and mature three-dimensional (3D) blood vessel networks in implantable tissues is critical when using these engineered tissues to treat a number of conditions, such as cardiovascular disease and trauma injuries,” said lead researcher Prof. Shulamit Levenberg of the Technion Department of Biomedical Engineering. “Matching the tissue structures will improve the long term viability and strength of tissue grafts when new blood vessel growth – called ‘angiogenesis’ – can be manipulated and exploited for the purpose of attaining optimal blood supply.”

    The team’s laboratory studies were aimed at determining just how vascular networks are regulated by various kinds of “tensile forces”- by stretching the constructs (3D engineered tissues).

    “Although mechanical forces play a central role in all biological processes as well as influence the shape and organization of cells, mechanical forces had not been previously investigated in relation to vascular networks in 3D,” explained Prof. Levenberg. “Our study used a number of techniques to monitor the impact of tensile forces on vascular network construction and properties.”

    The researchers examined the effects of cell-induced forces on vascular networks by applying variety of stretching forces, both cyclic (on-and-off) and static (constant) forces. The researchers found that the vessels aligned in response to the stretch.

    To test the effects vessel alignments on tissue integration, the researchers grafted engineered tissues into mouse abdominal muscles with the vessel direction placed both parallel and vertically to the natural mouse muscle fibers (host tissues). They found that tissues with vertically implanted blood vessels had greater stiffness and strength when they corresponded to the vertical direction of the host tissue fibers.

    This study was conducted in collaboration with Professor Dave Mooney, of Harvard University, who hosted Prof. Levenberg during her sabbatical year. The project was carried out by Dr. Dekel Dado-Rosenfeld as part of her PhD thesis, under the mentorship of Prof. Levenberg. Dr. Dado-Rosenfeld is currently a postdoc at the Massachusetts Institute of Technology, under the auspices of the MIT-Technion Post-Doctoral Fellowship.

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    Technion Campus

    A science and technology research university, among the world’s top ten,
    dedicated to the creation of knowledge and the development of human capital and leadership,
    for the advancement of the State of Israel and all humanity.

     
  • richardmitnick 10:26 am on March 8, 2016 Permalink | Reply
    Tags: , , Technion   

    From The Technion: “Cancer research: dramatic improvement in the efficiency of gene therapy” 

    Technion bloc

    Israel Institute of Technology

    07/03/2016
    No writer credit found

    The journal Nano Letters reports on innovative technology developed at the Technion: safe delivery of particles that leads to the production of the anti-cancer drug inside the target cell. In animal model experiments, the technology doubled life expectancy after the development of the disease.

    Fruitfly eye signals about cancer
    Fruitfly eye signals about cancer

    New technology for the delivery of targeted anti-cancer therapeutics in the body has been developed at the laboratory of Prof. Marcelle Machluf of the Technion. This technology dramatically increases the therapy’s efficacy and prevents the side effects associated with existing chemotherapy. In animal model experiments, the system doubled life expectancy after the development of the prostate cancer.

    Although treatment of symptoms is an important medical goal, the ultimate goal of medical practice is the eradication of the disease itself by treating its root causes. This is true, of course, for cancer medicine, which aims to eliminate the tumor and its metastases. Two problems in this area are the side effects of chemotherapy and the ability of cancer cells to develop resistance to these drugs.

    The good news is that gene therapy, which has enjoyed a research and clinical boom in recent decades, has already proven to be effective in treating tumors and metastases. The tool of genetic therapy is the insertion of genes, i.e., nucleic acid sequences that are coded for the production of proteins. This tool enables one of two things: (a) the creation of proteins that replace damaged or missing proteins in the target cell, or (b) the insertion of genes leading to the creation of anti-cancer proteins in the target cell. This can prevent the development of resistance to chemotherapy and reduce the side effects caused by dispersion of the toxic load on its way to the tumor.

    However, despite gene therapy’s great inherent potential for cancer therapy, its clinical application is still very limited. The widespread method in gene therapy – inserting genes into target cells using viruses – arouses a harsh response of the immune system in some cases. In addition, current treatments involve ‘seeping out’ of the drug on its way to the cancer target, resulting in damage to healthy tissue causing serious side effects.

    An article published on February 24 in the journal Nano Letters heralds a breakthrough in the accurate delivery of genes to the target without the use of viruses. The new technology, developed at the laboratory of Prof. Marcelle Machluf of the Technion Faculty of Biotechnology and Food Engineering, is an innovative delivery platform called Nano-Ghost. The Nano-Ghosts are tiny particles made from the outer membrane of a certain type of cells, called Mesenchymal Stem Cells. These cells are able to selectively target various cancers.

    With the technology developed by Prof. Machluf, together with doctoral student Limor Kaneti, these cells may be produced in large quantities in the laboratory, emptied of their contents and turned into empty packages – Nano-Ghosts. Specific genes are inserted into these packages and begin to produce an anti-cancer protein only upon reaching the tumor. Therefore they do not harm healthy tissue on their way to the target. Moreover, the anti-cancer protein affects not only the target cells into which the gene is inserted, but also the adjacent cancer cells and the blood vessels that support the tumor and are essential for its survival.

    The clinical use of this technology is simple: after the genetic material is loaded, the Nano-Ghosts are injected directly into the bloodstream, through which they navigate to the tumor. Since outwardly these are mesenchymal stem cells, the system detects these particles as friendly and does not harm them; and since the particles do not release their cargo en route, they cannot harm healthy tissues. Only after they have reached the malignant tissue and homed in on it do they insert the gene into the tumor cells and initiate the production of the anti-cancer protein. It should be noted that since these particles do not generate any immune rejection, there is no need to produce the mesenchymal stem cells from the patient himself.

    Animal model experiments have yielded very encouraging data: the new technology doubled the animal’s life expectancy after the development of prostate cancer, leading to a delay of over 75% in the development of prostate cancer, and of over 50% in the case of non-small cell lung carcinoma. No side effects and toxicity were observed in these animals, indicating the safety of the system.

    Prof. Marcelle Machluf is a world-renowned researcher in the fields of drug delivery, gene therapy, cell therapy and tissue engineering. Her lab is developing and engineering nano systems and micro systems for the delivery of drugs and genes (as in the present study); encapsulation (“packing”) of cellular systems for treating cancer and diabetes; and the development of scaffolds for cardiac, vascular and pancreatic tissue engineering. Prof. Machluf has published over 60 articles and book chapters, and seven of her patents in the process of registration.

    Link to the article: http://pubs.acs.org/doi/pdfplus/10.1021/acs.nanolett.5b04237

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    Technion Campus

    A science and technology research university, among the world’s top ten,
    dedicated to the creation of knowledge and the development of human capital and leadership,
    for the advancement of the State of Israel and all humanity.

     
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