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BiophotonicsWorld’s article

For the first time, light-inducible microRNA inhibitors are used as local therapeutic agents.

MicroRNAs are small gene fragments which bond onto target structures in cells and in this way prevent certain proteins from forming. As they play a key role in the occurrence and manifestation of various diseases, researchers have developed what are known as antimiRs, which block microRNA function. The disadvantage of this approach is, however, that the blockade can lead to side effects throughout the entire body since microRNAs can perform different functions in various organs. Researchers at Goethe University Frankfurt have now solved this problem.

The research groups led by Professor Alex Heckel and Professor Stefanie Dimmeler of the Cluster of Excellence Frankfurt Macromolecular Complexes have developed antimiRs that can be activated very effectively over a limited local area by using light of a specific wavelength. To this purpose, the antimiRs were locked in a cage of light-sensitive molecules that disintegrate as soon as they are irradiated with light of a specific wavelength.

As a means of testing the therapeutic effect of these new antimiRs, the researchers chose microRNA-92a as the target structure. This is frequently found in diabetes patients with slow-healing wounds. They injected the antimiRs in the light-sensitive cage into the skin of mice and then released the therapeutic agent into the tissue with the help of light. Together the research groups were able to prove that pinpointed activation of an antimiR against microRNA-92a helps wounds to heal.

"Apart from these findings, which prove for the first time that wound healing can be improved by using antimiRs to block microRNA-92a, our data also confirms that microRNA-92a function is indeed only locally inhibited. Other organs, such as the liver, were not affected", says Professor Stefanie Dimmeler, underlining the trials' clinical significance. 

The researchers now want to see whether they can also expand the use of light-inducible antimiRs to the treatment of other diseases. In particular they want to examine whether toxic antimiRs can attack tumors locally as well.

The article titled Light-inducible antimiR-92a as a therapeutic strategy to promote skin repair in healing-impaired diabetic mice by Tina Lucas, Florian Schäfer, Patricia Müller, Sabine A. Eming, Alexander Heckel & Stefanie Dimmeler: was published in Nature Communications, 2017, doi: 10.1038/ncomms15162

Press release of Goethe University Frankfurt/Main.
The new FISH-Flow protocol could lead to faster, more accurate diagnoses.

Rutgers researchers have developed a new way to analyze hundreds of thousands of cells at once, which could lead to faster and more accurate diagnoses of illnesses, including tuberculosis and cancers.

With the new FISH-Flow protocol, researchers are able to evaluate multitudes of cells at once for telltale mRNA species and proteins. The blended procedure provides a chance to see how multiple kinds of immune cells are responding to a foreign substance, making it possible to detect the presence of disease faster and earlier. 

"This new process allows us to see how individual immune cells are reacting in real time without using artificial reagents that alter what the cells are doing when they respond to a foreign substance," said Maria Laura Gennaro, a professor of medicine at Rutgers' Public Health Research Institute (PHRI). 

Gennaro is the lead author of a paper published in the journal Nature Protocols, which details the new method to observe how cells respond to antigens. The protocol could be used to identify telltale indicators of other illnesses. Gennaro said researchers plan to study applying it to early diagnosis and treatment of other infectious and non-infectious lung diseases and certain cancers.

"This powerful diagnostic technology exploits a person's own immune system to assess their potential for developing a wide range of acute and chronic diseases - including those caused by infectious agents and those resulting from host dysfunction like cancer, asthma or autoimmune disorders," said David Perlin, executive director of Rutgers New Jersey Medical School's Public Health Research Institute.

The procedure will be particularly useful in finding ways to help identify people who are predisposed to developing tuberculosis, making it possible to treat them and help reduce the spread of the disease. Nearly 2 billion people worldwide are afflicted with latent TB, but many never develop full-blown TB. Currently, the only way to determine if latent TB is present is to study the immunological response to TB antigens through skin tests and blood tests. However, treatment is not widely offered to people with latent TB because of the prohibitive cost of treating them all. 

"If you can have a method that helps you determine who among the people who are latently affected by TB are predisposed to illness, you can target treatment of latent TB to those people and the risk of spread is reduced," Gennaro said.

The FISH-Flow protocol combines flow-cytometry - a technology used to analyze particles in a fluid as they pass through a laser and are fluorescently labelled so they emit light at varying wavelengths - with a nucleic acid hybridization technology - originally developed for fluorescence microscopy - that marks molecules of mRNA inside cells. Gennaro developed the method with senior colleagues Yuri Bushkin, Richard Pine and Sanjay Tyagi at PHRI.

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Press release of Rutgers, The State University of New Jersey.

The research was funded by the National Institute of Allergy and Infectious Diseases. The procedure detailed in Nature Protocols also includes a semi-automated version developed by Gennaro's research group in collaboration with engineers at San Jose, California-based BD Biosciences that makes the method faster and highly reproducible for clinical applications.

Conjugated polymers designed with a twist produce tiny, brightly fluorescent particles with broad applications.

A strategy to produce highly fluorescent nanoparticles through careful molecular design of conjugated polymers has been developed by KAUST researchers. Such tiny polymer-based particles could offer alternatives to conventional organic dyes and inorganic semiconductor quantum dots as fluorescent tags for medical imaging. 

Conjugated polymer-derived nanoparticles, called Pdots, are expected to transform several areas, including optoelectronics, bio-imaging, bio-sensing and nanomedicine, due to their intense fluorescence, high stability under exposure to light and low cytotoxicity. Their spectroscopic properties are tunable by tweaking the polymer structures. This makes it essential to consider their design at the molecular level.  

Bio-imaging applications require nanoparticles small enough to be eliminated from the body and strongly emit light in the far-red to near-infrared range. However, current design and fabrication of Pdots have mostly relied on empirical approaches, hindering attempts to manufacture these ultrasmall nanoparticles.

To meet this challenge, Dr. Hubert Piwoński and Associate Professor Satoshi Habuchi came up with a systematic method that enhances the performance of Pdots. Habuchi explained that his team aimed to create Pdots of a smaller size and brighter fluorescence by using conjugated polymers, whose backbone of alternating single and multiple bonds enables so-called π electrons to move freely throughout the structure.

For the first time, the researchers opted for twisted, instead of planar, conjugated polymers as building blocks to generate their Pdots. Existing Pdots usually exhibit lower fluorescence intensity than their precursors as result of complex inter- and intra-chain photophysical interactions within particles. 

According to Habuchi, this trial was a shot in the dark—his team initiated the project without really knowing what would eventuate— but they were still surprised by the fluorescence behaviors of these Pdots compared to their previously investigated analogues. 

Preliminary results suggest that the newly synthesized nanoparticles were the smallest and brightest Pdots reported to date. “Therefore, we hypothesized that the twisted shape of the molecules is responsible for the very bright fluorescence due to the suppression of π–π interactions inside the particles,” explained Habuchi.  

The researchers validated their hypothesis by comprehensive photophysical and structural characterizations. “That was the most exciting moment of our project,” added Habuchi, noting that this demonstration has opened a new door for the correct prediction of the fluorescence properties of Pdots.

“We are now trying to introduce functional groups into these Pdots for bioconjugation,” Habuchi continued. The team is also designing and fabricating near-infrared-emitting nanoparticles.

The paper titled Controlling photophysical properties of ultrasmall conjugated polymer nanoparticles through polymer chain packing by Piwoński, H., Michinobu, T. & Satoshi Habuchi, S. was published in Nature Communications 8, 15256 (2017).

Press release of King Abdullah University of Science and Technology.

Engineers at the University of California San Diego have developed a miniature device that’s sensitive enough to feel the forces generated by swimming bacteria and hear the beating of heart muscle cells.

The device is a nano-sized optical fiber that’s about 100 times thinner than a human hair. It can detect forces down to 160 femtonewtons — about ten trillion times smaller than a newton — when placed in a solution containing live Helicobacter pylori bacteria, which are swimming bacteria found in the gut. In cultures of beating heart muscle cells from mice, the nano fiber can detect sounds down to -30 decibels — a level that’s one thousand times below the limit of the human ear.

“This work could open up new doors to track small interactions and changes that couldn’t be tracked before,” said nanoengineering professor Donald Sirbuly at the UC San Diego Jacobs School of Engineering, who led the study.

Some applications, he envisions, include detecting the presence and activity of a single bacterium; monitoring bonds forming and breaking; sensing changes in a cell’s mechanical behavior that might signal it becoming cancerous or being attacked by a virus; or a mini stethoscope to monitor cellular acoustics in vivo.

The optical fiber developed by Sirbuly and colleagues is at least 10 times more sensitive than the atomic force microscope (AFM), an instrument that can measure infinitesimally small forces generated by interacting molecules. And while AFMs are bulky devices, this optical fiber is only several hundred nanometers in diameter. “It’s a mini AFM with the sensitivity of an optical tweezer,” Sirbuly said.

The device is made from an extremely thin fiber of tin dioxide, coated with a thin layer of a polymer, called polyethylene glycol, and studded with gold nanoparticles. To use the device, researchers dip the nano optical fiber into a solution of cells, send a beam of light down the fiber and analyze the light signals it sends out. These signals, based on their intensity, indicate how much force or sound the fiber is picking up from the surrounding cells.

“We’re not just able to pick up these small forces and sounds, we can quantify them using this device. This is a new tool for high resolution nanomechanical probing,” Sirbuly said.

Here’s how the device works: as light travels down the optical fiber, it interacts strongly with the gold nanoparticles, which then scatter the light as signals that can be seen with a conventional microscope. These light signals show up at a particular intensity. But that intensity changes when the fiber is placed in a solution containing live cells. Forces and sound waves from the cells hit the gold nanoparticles, pushing them into the polymer layer that separates them from the fiber’s surface. Pushing the nanoparticles closer to the fiber allows them to interact more strongly with the light coming down the fiber, thus increasing the intensity of the light signals. Researchers calibrated the device so they could match the signal intensities to different levels of force or sound.

The key to making this work is the fiber’s polymer layer. It acts like a spring mattress that’s sensitive enough to be compressed to different thicknesses by the faint forces and sound waves produced by the cells. And Sirbuly says the polymer layer can be tuned — if researchers want to measure larger forces, they can use a stiffer polymer coating; for increased sensitivity, they can use a softer polymer like a hydrogel.

Moving forward, researchers plan to use the nano fibers to measure bio-activity and the mechanical behavior of single cells. Future works also includes improving the fibers’ “listening” capabilities to create ultra-sensitive biological stethoscopes, and tuning their acoustic response to develop new imaging techniques.

The paper titled “Nanofibre optic force transducers with sub-piconewton resolution via near-field plasmon-dielectric interactions” by Qian Huang, Joon Lee, Fernando Teran Arce, Ilsun Yoon, Pavimol Angsantikul, Justin Liu, Yuesong Shi, Josh Villanueva, Soracha Thamphiwatana, Xuanyi Ma, Liangfang Zhang, Shaochen Chen, Ratnesh Lal and Donald J. Sirbuly was published in Nature Photonics.

This work was supported by the National Science Foundation (ECCS 1150952) and the University of California, Office of the President (UC-LFRP 12-LR-238415). 

Press release of the University of California San Diego.

An international team of researchers from the University of California, Los Angeles and the Braunschweig University of Technology in Germany has developed an approach to enhance the sensitivity of smartphone-based fluorescence microscopes by ten-fold compared to previously reported mobile phone-based handheld microscopes. This is an important development toward the use of mobile phones for advanced microscopic investigation of samples, sensing of disease biomarkers, tracking of chronic conditions, and molecular diagnostics and testing in general.

Fluorescence is one of the predominant detection modalities for molecular diagnostic tools and medical tests due to the sensitivity and specificity that it enables. Smartphone-based microscopy and sensing techniques require improved detection sensitivity to enable quantification of extremely low concentrations of target molecules, for example, cancer biomarkers, pathogen proteins or even DNA. Therefore, these recent results on enhanced  microscopy using mobile phones are especially important to provide highly sensitive, mobile and cost-effective readers for molecular diagnostic tests, potentially impacting  and point-of-care applications.

The sensitivity enhancement was accomplished by placing fluorescent samples on a thin silver film. Although the thickness of the silver film is approximately 2,000-fold thinner than a human hair, it is sufficient to enhance the strength of the excitation light, especially in the vicinity of the fluorescent samples. This is achieved by coupling the energy of an optical beam into plasmonic waves (known as surface plasmon polaritons) that are formed by electron oscillations in the silver film. This plasmonics-based optical enhancement resulted in a cost-effective  fluorescence microscope that weighs approximately 370 grams, including the smartphone, and achieved repeatable detection of single quantum dots and as few as ~50-80 fluorophores per sample spot. Compared to standard benchtop fluorescence microscopes, this mobile device is more than 20-fold cheaper and lighter.

"We are now capable of detecting a few tens of fluorophores for each  spot using a low-cost pocket , enabled by plasmonics and mobile phones. This will create numerous opportunities for bringing advanced molecular testing and diagnostics for tackling global health problems, especially in developing countries," said Aydogan Ozcan, who led the research team at UCLA and is a Chancellor's Professor of Electrical Engineering and Bioengineering and an associate director of the California NanoSystems Institute (CNSI).

The article "Plasmonics Enhanced Smartphone Fluorescence Microscope" by Qingshan Wei, Guillermo Acuna, Seungkyeum Kim, Carolin Vietz, Derek Tseng, Jongjae Chae, Daniel Shir, Wei Luo, Philip Tinnefeld and Aydogan Ozcan was published in Scientific Reports 7, Article number: 2124 (2017), DOI: 10.1038/s41598-017-02395-8 

Press release of the Ozcan Research Group at the University of California Los Angeles.

Minimally invasive endoscope using breakthrough photonics technology to enable rapid, accurate diagnosis of bowel polyps and early colon cancer.

Funded under Horizon 2020, the EU’s research and innovation programme, a European group of scientists are working on the development of an innovative, compact and easy to use endoscopic device, which will play a crucial role in identifying and diagnosing pre-cancerous polyps and early colon cancers. Worldwide, colon cancer remains the third most common cancer in men, behind lung and prostate cancer, and second in women, behind breast cancer.

Colorectal cancer ranks as one of the world’s most predominant cancers, affecting approximately one in ten people during their life and causing almost 700,000 annual deaths globally. Almost 95% of these cases are adenocarcinomas, which typically start as a growth of tissue called a polyp.

Today, the main method to achieve early detection of the disease is colonoscopy. While up to 40% of the patients under routine analysis colonoscopy present one or more polyps, almost 30% of these polyps are not detected, especially in the case of flat polyps. Of those detected, 29-42% are generally hyperplastic, and will not develop into cancer. The remainder are neoplastic polyps, which are of primary importance because they harbor malignant potential and represent a stage in the development of colorectal cancer. For this reason, it is essential to identify these polyps at an early stage.

Speaking about the PICCOLO Project Dr. Artzai Picon (Tecnalia) said "We hope that PICCOLO will provide major benefits over traditional colonoscopy. Firstly, by developing an advanced endoscope, using both Optical Coherence Tomography (OCT) & Multi-Photon Tomography (MPT), we will provide high-resolution structural and functional imaging, giving details of the changes occurring at the cellular level comparable to those obtained using traditional histological techniques. Furthermore, when multiple polyps are detected in a patient, the current gold standard procedure is to remove all of them, followed by microscopic tissue analysis. Removal of hyperplastic polyps, which carry no malignant potential, and the subsequent costly histolopathological analysis might be avoided through the use of the PICCOLO endoscope probe, which could allow image-based diagnosis without the need for tissue biopsies".

The long term potential for this project is exciting. Not only will it provide a new approach in colon cancer detection, but the new image based diagnosis methods could be applied to diseases in other organs of the body. The PICCOLO team hopes to have refined their first prototype by the end of 2018 and targets clinical trials to begin around 2020.

Press release of PICCOLO Project.

A new study shows that the Apple Watch's heart rate sensor, when paired with an artificial intelligence-based algorithm, can detect a serious and often symptomless heart arrhythmia, atrial fibrillation (AF). The new research uses a deep neural network based on photoplethysmographic (PPG) sensors commonly found in smart watches. The results of this study were presented at Heart Rhythm 2017, the Heart Rhythm Society’s 38th Annual Scientific Sessions.

AF, the most common heart arrhythmia, affects more than 2.7 million American adults. While AF may present symptoms such as palpitations and fatigue, it is often asymptomatic, causing no alarm to doctors or patients and making diagnosis difficult. According to a national survey of 1,000 Americans, one in five Americans owns a wearable fitness tracker such as a smart watch or Fitbit1. With the growing number of people using this mobile technology, there is an opportunity to address public health issues such as undiagnosed AF in a way that is convenient for many.

The study enrolled 6,158 users of Cardiogram for Apple Watch into the UCSF Health eHeart Study. Data from those participants—including 139 million heart rate measurements and 6,338 mobile ECGs—was used to train a deep neural network to automatically distinguish atrial fibrillation from normal heart rhythm.

The deep neural network was validated against a cohort of 51 patients set to undergo cardioversion, a procedure that restores the heart to a normal rhythm. Each patient wore an Apple Watch for 20 minutes pre-and-post cardioversion. With a 12-lead electrocardiogram as a reference standard, the DNN correctly detected atrial fibrillation with an accuracy (c-statistic) of 97%, a sensitivity of 98.04%, and a specificity of 90.20%, higher than previously-validated algorithms for detection of AF.

“Our results show that common wearable trackers like smartwatches present a novel opportunity to monitor, capture and prompt medical therapy for atrial fibrillation without any active effort from patients,” said senior author, Gregory M. Marcus, MD, MAS Endowed Professor of Atrial Fibrillation Research and Director of Clinical Research for the Division of Cardiology at University of California, San Francisco. “While mobile technology screening won’t replace more conventional monitoring methods, it has the potential to successfully screen those at an increased risk and lower the number of undiagnosed cases of AF.”

The Health eHeart Study seeks to gather more data about heart health from more people than any research study has done before and develop strategies to prevent and treat all aspects of heart disease. Cardiogram seeks to predict and prevent heart disease using artificial intelligence.

The authors of the Apple Watch study are currently working on expanding the number of participants, exploring success rates of self-diagnosis, and testing the ability of the deep neural network to identify other health conditions.

1 PwC Health Research Institute and Consumer Intelligence Series. (2014) “Health wearables: Early days”.

Sessions details: 

“AF Detection and Ablation Outcomes: Answering Questions That Matter to Patients: Detecting Atrial Fibrillation using a Smart Watch – the mRhythm study” [May 11, 2017 1:30 p.m. – 3:00 p.m. Room 183B]

Heart Rhythm 2017 is the most comprehensive educational program for heart rhythm professionals, featuring more than 250 educational sessions and more than 130 exhibitors showcasing innovative products and services. The Heart Rhythm Society’s Annual Scientific Sessions have become the must-attend event of the year, allowing the exchange of new vital ideas and information among colleagues from every corner of the globe. For more information, visit www.hrssessions.org

About the Heart Rhythm Society

The Heart Rhythm Society is the international leader in science, education and advocacy for cardiac arrhythmia professionals and patients, and the primary information resource on heart rhythm disorders. Its mission is to improve the care of patients by promoting research, education and optimal health care policies and standards. Incorporated in 1979 and based in Washington, DC, it has a membership of more than 5,900 heart rhythm professionals in more than 70 countries around the world. For more information, visit www.HRSonline.org.

See more at: http://www.hrsonline.org/News/Press-Releases/2017/05/Artificial-Intelligence-Automatically-Detects-AFib#sthash.Pu3ca8Z2.dpuf


Media Contact

Allison Kassel

BRG Communications

akassel@brgcommunications.com


Shane Osborne

Heart Rhythm Society

media@hrsonline.org

Plenary presentations detailed latest developments in Gravitational Wave Science, Ultrafast Lasers, Quantum Electronics and Biophotonics.

The Optical Society announced today that CLEO 2017 (CLEO) has concluded with more than 4,000 attendees, 200 exhibitors and over 2,000 research presentations. With comprehensive, peer-reviewed technical sessions and market focused exhibit-floor programming, CLEO provided attendees an unparalleled opportunity to immerse themselves in a broad range of fundamental and applied laser science research. From quantum cascade lasers on silicon, to skin-mounted wearables and high capacity quantum computers, this year’s CLEO conference provided a platform to foster the development of today’s laser and electro-optical devices.

Comprehensive High-Quality Programming
“CLEO provides high-quality programming that marries industry and academic research sparking innovation in a number of critical applications — from biomedical applications to industrial lasers and photonics applications,” said Nicusor Iftimia, Physical Sciences Inc., USA, general co-chair of CLEO.
               
Keynote Programming
Christopher Contag, Stanford University, USA 
Insertable, Implantable and Wearable Micro-optical Devices for the Early Detection of Cancer
Optical imaging tools have the ability to scale from a macro- to a nanoscopic resolution. This provides higher imaging resolution at the cellular level — an important step in cancer detection. Contag’s presentation detailed developments in the field of optical imaging for cancer identification, diagnosis, prognosis and therapy.

Ataç İmamoğlu, ETH Zurich, Switzerland
Polaritons in Two-dimensional Electron Systems
Cavity-polaritons have emerged as an exciting platform for studying the interactions of bosons in a driven-dissipative setting. During his plenary presentation, İmamoğlu described current activities in cavity spectroscopy supporting research thrusts in quantum dot technologies.

Ursula Keller, ETH Zurich, Switzerland
Ultrafast Solid-state Lasers:  A Success Story with no End in Sight
From precision micromachining, to high frequency metrology and nonlinear microscopy, the ultrafast solid-state laser market continues to grow in technology applications. Keller’s presentation detailed the latest research in passive modelocking for power scaling of diode-pumped, ion-doped solid-state and semiconductor lasers.
 
Nergis Mavalvala, Massachusetts Institute of Technology, USA
Gravitational Wave Detectors of the Future: Beyond the First LIGO Discoveries
In February 2016, scientists announced the first ever detection of gravitational waves from colliding black holes, launching a new era of gravitational wave astronomy and unprecedented tests of Einstein’s theory of general relativity. Searching for fainter or more distant sources requires ever greater sensitivity for the laser interferometric detectors that made these first discoveries. Mavalvala’s presentation described current efforts to improve the sensitivity of gravitational wave detectors and their prospects for future discoveries.
 
Industry Leading Companies in Lasers and Electro-Optics
More than 200 companies exhibited at CLEO 2017, taking advantage of the annual industry-leading gathering to introduce new products and demonstrate cutting-edge innovations. Companies such as Calmar Laser, Coherent, Continuum, Edmund Optics, Newport, Menlo Systems, Thorlabs, Toptica Photonics and many others showcased state-of-the-art technology including; ultrafast lasers, spectroscopy, optical pulse technology and nanophotonics. The CLEO exhibit hall featured presentations on the state of the optics and photonics industry, precision manufacturing using ultrafast lasers and special topical symposia on: Advances in Metaphotonic Devices, Military Applications Of High Power Lasers, Multimodal Imaging in Biophotonics, Optical Microcavities for Ultrasensitive Detection and more.

 
About CLEO
With a distinguished history as the industry's leading event on laser science, the Conference on Lasers and Electro-Optics (CLEO) is the premier international forum for scientific and technical optics, uniting the fields of lasers and opto-electronics by bringing together all aspects of laser technology, from basic research to industry applications. For more information, visit the event website at cleoconference.org. Save the date for CLEO 2018, 13 – 18 May at the San Jose Convention Center in San Jose, California, USA.

About The Optical Society
Founded in 1916, The Optical Society (OSA) is the leading professional organization for scientists, engineers, students and business leaders who fuel discoveries, shape real-life applications and accelerate achievements in the science of light. Through world-renowned publications, meetings and membership initiatives, OSA provides quality research, inspired interactions and dedicated resources for its extensive global network of optics and photonics experts. For more information, visit osa.org.

Press release of The Optical Society.

Researchers at Université Laval's Faculty of Science and Engineering and its Center for Optics, Photonics, and Lasers have created a smart T-shirt that monitors the wearer's respiratory rate in real time. This innovation, the details of which are published in the latest edition of Sensors, paves the way for manufacturing clothing that could be used to diagnose respiratory illnesses or monitor people suffering from asthma, sleep apnea, or chronic obstructive pulmonary disease. 

Unlike other methods of measuring respiratory rate, the smart T shirt works without any wires, electrodes, or sensors attached to the user's body, explains Younes Messaddeq, the professor who led the team that developed the technology. "The T shirt is really comfortable and doesn't inhibit the subject's natural movements. Our tests show that the data captured by the shirt is reliable, whether the user is lying down, sitting, standing, or moving around."

The key to the smart T shirt is an antenna sewn in at chest level that's made of a hollow optical fiber coated with a thin layer of silver on its inner surface. The fiber's exterior surface is covered in a polymer that protects it against the environment. "The antenna does double duty, sensing and transmitting the signals created by respiratory movements," adds Professor Messaddeq, who also holds the Canada Excellence Research Chair in Photonic Innovations. "The data can be sent to the user's smartphone or a nearby computer."

As the wearer breathes in, the smart fiber senses the increase in both thorax circumference and the volume of air in the lungs, explains Messaddeq. "These changes modify some of the resonant frequency of the antenna. That's why the T shirt doesn't need to be tight or in direct contact with the wearer's skin. The oscillations that occur with each breath are enough for the fiber to sense the user's respiratory rate."

To assess the durability of their invention, the researchers put a T shirt equipped with an antenna through the wash--literally. "After 20 washes, the antenna had withstood the water and detergent and was still in good working condition," says Messaddeq.

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In addition to Messaddeq, the study's coauthors are Philippe Guay, Stepan Gorgutsa, and Sophie LaRochelle.

Press release of Université Laval.

New microscopy technique could reduce repeat surgeries for breast cancer patients.

Engineers at the Optical Imaging Laboratory led by Caltech's Lihong Wang have developed an imaging technology that could help surgeons removing breast cancer lumps confirm that they have cut out the entire tumor--reducing the need for additional surgeries. 

About 300,000 new cases of invasive breast cancer are discovered annually. Of these, 60 to 75 percent of patients underwent breast-conserving surgery.

Breast-conserving surgeries, or lumpectomies, attempt to remove the entire tumor while retaining as much of the undamaged breast tissue as possible. (In contrast, a mastectomy removes the entire breast.) The extracted tissue is then sent to a lab where it is rendered into thin slices, stained with a dye to highlight key features, and then analyzed. If tumor cells are found on the surface of the tissue sample, it indicates that the surgeon has cut through, not around, the tumor--meaning that a portion of the tumor remains inside the patient, who will then need a follow-up surgery to have more tissue removed.

After a week or two waiting for lab results, 20 to 60 percent of patients find out that they must return for a second surgery to have more tissue removed. But, asks Wang, "what if we could get rid of the waiting? With 3D photoacoustic microscopy, we could analyze the tumor right in the operating room, and know immediately whether more tissue needs to be removed." Wang is a Bren Professor of Medical Engineering and Electrical Engineering in Caltech's Division of Engineering and Applied Science. His lab invented 3D photoacoustic microscopy.

Photoacoustic microscopy, or PAM, excites a tissue sample with a low-energy laser, which causes the tissue to vibrate. The system measures the ultrasonic waves emitted by the vibrating tissue. Because nuclei vibrate more strongly than surrounding material, PAM reveals the size of nuclei and the packing density of cells. Cancerous tissue tends to have larger nuclei and more densely packed cells.

Indeed, as described by Wang and his team in a paper publishing in the journal Science Advances on May 17, PAM produces images capable of highlighting cancerous features, with no slicing or staining required.

Wang conducted this research while the Optical Imaging Laboratory was located at Washington University in St. Louis. He moved the lab to Caltech's Andrew and Peggy Cherng Department of Medical Engineering in January 2017.

Although Wang's team has focused primarily on breast cancer tumors, his work has potential applications for any analysis of excised tumors--from melanoma to pancreatic cancer. In a proof-of-concept scan described in the new paper, PAM analyzed a sample in about three hours. Comparable traditional microscopy takes about seven hours to achieve the same results. However, Wang says that PAM's analysis time could be cut down to 10 minutes or less with the addition of faster laser pulse repetition and parallel imaging. This would make the technology useful for clinical applications.

"Because the device never directly touches a patient, there will be fewer regulatory hurdles to overcome before gaining FDA approval for use by surgeons," Wang says. "Potentially, we could make this tool available to surgeons within several years."

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The Science Advances paper is titled "Fast label-free multilayered histology-like imaging of human breast cancer by photoacoustic microscopy." Among the coauthors are Terence Wong, Ruiying Zhang, Pengfei Hai, Chi Zhang, and Miguel Pleitez, who are current or former members of the Optical Imaging Laboratory, and Rebecca Aft and Deborah Novack, who are clinical collaborators at Washington University. This research was funded by the National Institutes of Health and the Siteman Cancer Center.

Press release of Caltech.

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