Tag Archives: fiber

Scientists create new fiber that’s as flexible as skin, but tougher

Credit: North Carolina State University.

Researchers at the North Carolina State University have devised a new material that combines the elasticity of rubber with the strength of steel. The resulting material can stretch up to seven times its original length before failure while simultaneously being able to undergo a lot of strain. The material can also conduct electricity and regenerate itself, making it a promising candidate for stretchable electronics and soft robotics.

The fiber mimics human tissue which often combines several components to obtain a greater resilience against external loads. For instance, skin is made of a network of collagen bundled fibers which dissipate energy and prevent cuts from spreading. Human muscle absorbs tensile loads in a similar way with the help of the biomolecule titin.

“A good way of explaining the material is to think of rubber bands and metal wires,” said Professor Michael Dickey, lead author of the new study published in Science Advances.  “A rubber band can stretch very far, but it doesn’t take much force to stretch it. A metal wire requires a lot of force to stretch it, but it can’t take much strain – it breaks before you can stretch it very far. Our fibers have the best of both worlds.”

Dickey and colleagues took a gallium metal core and covered it in an elastic polymer sheath. The fiber basically has the strength of the metal core. However, it won’t fail when the metal breaks because the polymer absorbs the strain between the breaking points, transferring the stress back to the metal. This is similar to how human tissue will still hold together broken bones.

You can see the fiber in action in the video below:

“Every time the metal core breaks it dissipates energy, allowing the fiber to continue to absorb energy as it elongates,” Dickey says. “Instead of snapping in two when stretched, it can stretch up to seven times its original length before failure, while causing many additional breaks in the wire along the way.

“To think of it another way, the fiber won’t snap and drop a heavy weight. Instead, by releasing energy repeatedly through internal breaks, the fiber lowers the weight slowly and steadily.”

The galium core is also conductive, making the fiber ideal in electronics and soft robotics, besides applications such as packaging materials or next-generation textiles.

“We used gallium for this proof of concept work, but the fibers could be tuned to alter their mechanical properties, or to retain functionality at higher temperatures, by using different materials in the core and shell.”

“This is only a proof of concept, but it holds a lot of potential. We are interested to see how these fibers could be used in soft robotics or when woven into textiles for various applications.”

WHO report: You should eat 25g of fiber every day — and you probably don’t

A new report published by the World Health Organization (WHO) concludes that over 25 grams of fiber every day provides great health benefits, helping protect against cardiovascular disease, diabetes, and a swarm of other health issues. But most people aren’t even coming close to that number.

Replacing white bread and pasta with whole wheat is an excellent starting point if you want to eat more fiber. Image credits: anaterate.

Eat more fiber

There’s no such thing as an ideal diet, a recent study confirmed. However, all the “good” diets have one thing in common: a substantial amount of fiber. Dietary fiber is the portion of plant-derived food that cannot be completely broken down through digestion — but even though you don’t digest it, it can do wonders for your health.

This fiber has many functions in diet, one of which may be to aid in energy intake control and reduced risk for development of obesity. So already, dietary fiber helps against obesity, which means it indirectly helps protect against the numerous health issues brought on by obesity — but there’s more to it than that. Fiber adds bulk to the stool, which alleviates constipation, and helps regulate blood sugar.

So it should be no surprise that fiber plays a key role in healthy diets — the new report goes a great way towards confirming that and quantifying the amount of fiber that yields the most benefits.

Just how much?

The WHO researchers carried out a series of systematic reviews and meta-analyses of prospective studies and randomized controlled trials. In total, they had 185 prospective studies and 58 clinical trials with 4635 adult participants. Overall, results indicated a 15–30% decrease in all-cause and cardiovascular-related mortality, and incidence of coronary heart disease, stroke incidence and mortality, type 2 diabetes, and colorectal cancer when comparing the highest dietary fibre consumers with the lowest consumers. Higher consumption of fiber also correlated positively with lower bodyweight, systolic blood pressure, and total cholesterol.

But how much fiber was enough? The bare minimum is 25 grams per day, researchers say.

“Risk reduction associated with a range of critical outcomes was greatest when daily intake of dietary fibre was between 25 g and 29 g,” researchers say. Eating over 29 g yielded even better results. “Dose-response curves suggested that higher intakes of dietary fibre could confer even greater benefit to protect against cardiovascular diseases, type 2 diabetes, and colorectal and breast cancer. Similar findings for whole grain intake were observed.”

This is consistent with current recommendations. For instance, the United States National Academy of Sciences, Institute of Medicine recommends that “adult men ages 14–50 consume 38 grams of dietary fiber per day, men 51 and older 30 grams, women ages 19–50 to consume 25 grams per day, women 51 and older 21 grams.” Similarly, the British Nutrition Foundation has recommended a minimum fiber intake of 30 grams per day for healthy adults — but few people actually respect that.

Plants alone contain dietary fiber. So if you want to make sure you eat more fiber, fruits and veggies are your friends. Image in public domain.

In the US, the average person consumes less than 50% of the dietary fiber levels recommended for good health, a factor which many scientists feel is decisive for the dramatic obesity crisis experienced by the country. To make matters even worse, youths consume even less fiber than the average American: around 20% of what they should.

However, the US isn’t the only country which needs to be eating more fiber. In the UK, just 9% of adults eat enough daily fiber, and similar trends are reported in much of the developing world. The lack of fiber is a main characteristic of the modern “Western Diet,” and the effects are starting to show.

Things are even more concerning as many of today’s popular diets are low-carb diets, which turn their back on fiber even more.

How to get your fiber

So how can you make sure you eat enough fiber? The key, as you might have guessed, lies in one word: plants. Foods of animal origin do not contain dietary fiber. So here’s a few ideas to help you reach 30g a day:

  • Cereals. An average 40g portion of bran flakes contains 8g of fiber, though most people eat far more than 40g of cereal. Oats have similar amounts.
  • Pulses like lentil or lentil. Black beans and lentil contain around 10-16g of fibers per cup. They are also very high in protein. Green peas have 9-10g / cup.
  • Fruits. An apple has around 5g of fiber. A pear has 6, and a cup of raspberries has 10. A banana, however, has only 3-4 grams — and when it’s very ripe, it has even less.
  • Whole wheat bread and spaghetti. Here’s a good tip: if you want more fiber in your diet, replace the white flour in your diet with whole flour. This applies to bread, spaghetti, and every other flour-based product. A serving of whole wheat spaghetti contains around 5 grams of fiber, while whole wheat bread has about 2g per slice.

The study has been published in The Lancet.

A fiber-rich diet can protect against the flu

Researchers have found an unexpected ally for protecting the body against the flu: dietary fiber.

Want to avoid the flu? Eat more fiber, a new study suggests.

More and more research is showing just how important our diet is for preventing a number of diseases and health conditions. It’s not just about straightforward problems, like diabetes or cardiovascular diseases — sometimes the prevention effect can be rather surprising. In this case, it seems that dietary fiber can blunt excessive and harmful immune responses in the lungs, while at the same time boosting antiviral immunity by activating T cells. This whole process is mediated by changes in the composition of gut bacteria.

“The beneficial effects of dietary fiber and SCFAs on a variety of chronic inflammatory diseases, including asthma and allergies, have received substantial attention in recent years and have supported momentum toward their use in clinical studies,” says senior study author Benjamin Marsland of Monash University. “But we were concerned that these treatments might lead to a general dampening of immune responses and could increase susceptibility to infections.”

Influenza, commonly known as “the flu”, affects millions of people every year, being one of the most common viral infections in the world. Aside from being extremely unpleasant, influenza can also be dangerous — and in some cases, fatal. Finding a way to boost immunity through diet alone would be a valuable tool for public health.

Dietary fiber is essentially the indigestible portion of food derived from plants. Although we don’t digest it directly, we can still draw a number of very important benefits from them. Dietary fiber helps keep our digestive system healthy, fighting obesity and severe diseases such as bowel cancer. It generally does this by keeping your gut bacteria healthy, but in the case of influenza, it’s a bit strange: the fiber seems to selectively turn on some parts of the immune system while switching others off — both to positive effect.

“We typically find that a certain treatment turns our immune system either on or off,” Marsland says. “What surprised us was that dietary fiber was selectively turning off part of our immune system, while turning on another, completely unrelated part of our immune system.”

This study also suggests that the so-called Western diet (high in sugars and fats, low in fiber) increases susceptibility to inflammatory diseases while decreasing protection against infections, something which has already been confirmed.

However, this study has only been carried out on mice. There’s a good chance the results will carry over to humans (something which researchers will test in the near future), but it remains to be seen if this is the case. At any rate, adding more fiber to your diet is always recommended, and will almost certainly provide significant health benefits.

Journal Reference: Immunity, Trompette and Gollwitzer et al.: “Dietary Fiber Confers Protection against Flu by Shaping Ly6c- Patrolling Monocyte Hematopoiesis and CD8+ T Cell Metabolism” http://www.cell.com/immunity/fulltext/S1074-7613(18)30191-2

Meet your new organ: the interstitium

Doctors have identified a previously unknown feature of human anatomy with many implications for the functions of most organs and tissues, and for the mechanisms of most major diseases.

Structural evaluation of the interstitial space. (A) Transmission electron microscopy shows collagen bundles (asterisks) that are composed of well-organized collagen fibrils. Some collagen bundles have a single flat cell along one side (arrowheads). Scale bar, 1 μm. (B) Higher magnification shows that cells (arrowhead) lack features of endothelium or other types of cells and have no basement membrane. Scale bar, 1 μm. (C) Second harmonics generation imaging shows that the bundles are fibrillar collagen (dark blue). Cyan-colored fibers are from autofluorescence and are likely elastin, as shown by similar autofluorescence in the elastic lamina of a nearby artery (inset) (40×). (D) Elastic van Gieson stain shows elastin fibers (black) running along collagen bundles (pink) (40×).

A new paper published on March 27th in Scientific Reports, shows that layers of the body long thought to be dense, connective tissues — below the skin’s surface, lining the digestive tract, lungs, and urinary systems, and surrounding arteries, veins, and the fascia between muscles — are instead interconnected, fluid-filled spaces.

Scientists named this layer the interstitium — a network of strong (collagen) and flexible (elastin) connective tissue fibers filled with fluids, that acts like a shock absorber to keep tissues from rupturing while organs, muscles, and vessels constantly pump and squeeze throughout the day.

This fluid layer that surrounds most organs may explain why cancer spreads so easily. Scientists think this fluid is the source of lymph, the highway of the immune system.

In addition, cells that reside in the interstitium and collagen bundles they line, change with age and may contribute to the wrinkling of skin, the stiffening of limbs, and the progression of fibrotic, sclerotic and inflammatory diseases.

Scientists have long known that more than half the fluid in the body resides within cells, and about a seventh inside the heart, blood vessels, lymph nodes, and lymph vessels. The remaining fluid is “interstitial,” and the current paper is the first to define the interstitium as an organ in its own right and, the authors write, one of the largest of the body, the authors write.

A team of pathologists from NYU School of Medicine thinks that no one saw these spaces before because of the medical field’s dependence on the examination of fixed tissue on microscope slides. Doctors examine the tissue after treating it with chemicals, slicing it thinly, and dyeing it in various colorations. The “fixing” process allows doctors to observe vivid details of cells and structures but drains away all fluid. The team found that the removal of fluid as slides are made makes the connective protein meshwork surrounding once fluid-filled compartments to collapse and appear denser.

“This fixation artifact of collapse has made a fluid-filled tissue type throughout the body appear solid in biopsy slides for decades, and our results correct for this to expand the anatomy of most tissues,” says co-senior author Neil Theise, MD, professor in the Department of Pathology at NYU Langone Health. “This finding has potential to drive dramatic advances in medicine, including the possibility that the direct sampling of interstitial fluid may become a powerful diagnostic tool.”

Researchers discovered the interstitium by using a novel medical technology — Probe-based confocal laser endomicroscopy. This new technology combines the benefits of endoscopy with the ones of lasers. The laser lights up the tissues, sensors analyze the reflected fluorescent patterns, offering a microscopic real-time view of the living tissues.

When probing a patient’s bile duct for cancer spread, endoscopists and study co-authors Dr. David Carr-Locke and Dr. Petros Benias observed something peculiar — a series of interconnected spaces in the submucosa level that was never described in the medical literature.

Baffled by their findings, they asked Dr. Neil Theise, professor in the Department of Pathology at NYU Langone Health and co-author of the paper for help in resolving the mystery. When Theise made biopsy slides out of the same tissue, the reticular pattern found by endomicroscopy vanished. The pathology team would later discover that the spaces seen in biopsy slides, traditionally dismissed as tears in the tissue, were instead the remnants of collapsed, previously fluid-filled, compartments.

Researchers collected tissues samples of bile ducts from 12 cancer patients during surgery. Before the pancreas and the bile duct were removed, patients underwent confocal microscopy for live tissue imaging. After recognizing this new space in images of bile ducts, the team was able to quickly spot it throughout the body.

Theise believes that the protein bundles seen in the space are likely to generate electrical current as they bend with the movements of organs and muscles, and may play a role in techniques like acupuncture.

Another scientist involved in the study was first author Rebecca Wells of the Perelman School of Medicine at the University of Pennsylvania, who determined that the skeleton in the newfound structure was comprised of collagen and elastin bundles.

A schematic that illustrates the various applications of a smart fiber sensing network. Image: Stepan Gorgutsa, Universite Laval

Smart fibers can turn your sweater into a medical monitoring station

The more data doctors have of their patients’ health, the better the treatments they can prescribe. Ideally, you’d want patients to be constantly monitored for key life signs like heart rhythm, glucose levels or even brain activity. Typically, this is only possible in a hospital setting, but what if you want to follow how a patient is doing in real time for long periods of time, months or even years? A non-invasive technique would be to embed both monitoring and signaling devices directly into the clothing. Canadian researchers have faith something like this is possible using so-called  “smart textiles” which they developed.

Smart fibers for smart clothing

A schematic that illustrates the various applications of a smart fiber sensing network. Image:  Stepan Gorgutsa, Universite Laval

A schematic that illustrates the various applications of a smart fiber sensing network. Image: Stepan Gorgutsa, Universite Laval

“The fiber acts as both sensor and antenna. It is durable but malleable, and can be woven with wool or cotton, and signal quality is comparable to commercial antennas,” explained Professor Younes Messaddeq at Université Laval’s Faculty of Science and Engineering and Centre for Optics, Photonics and Lasers.

Smart fabric is durable, malleable, and can be woven with cotton or wool. Horizontal lines are antennas. (Credit: Stepan Gorgutsa, Universite Laval)

Smart fabric is durable, malleable, and can be woven with cotton or wool. Horizontal lines are antennas. (Credit: Stepan Gorgutsa, Universite Laval)

The fibers are made out of a polymer-clad silica with a hollow-core. The material can easily withstand high tensile and bending stresses, meaning it can easily twist and shrug as is often the case with clothing. The fibers are also resistant to mechanical abrasion and harsh environments like humidity, high temperatures, acid or detergent exposure due to the thick polyimide polymer overcoat.

All the conducting elements are inside the fibers, which are thick enough to protect the wiring against  the environment. Various sensors can be attached to the surface to monitor key health signals, which are then relayed through 2.4 GHz wireless networks with excellent signal quality. A shirt that registers your heart rate or a cap that reads your brain activity is now possible. Medical monitoring doesn’t need to be bulky and invasive; tucked inside smart fibers and woven along with regular cotton fibers, virtually any stylish clothing could be turned into a medical station.

The findings were described in a paper published in the journal Sensors. [story via KurzweilAI]