Isegoria

For decades, chemists have known how to interlock individual molecular rings, or small groups of them, but a reliable way to interlock large groups of these rings into strings and sheets had so far eluded them:

Researchers led by William Dichtel, a chemist at Northwestern University, have now done just that. They started by coaxing myriad copies of X-shaped molecules to settle into a crystal, so that they lined up in two interpenetrating sheets: In one direction the tips of each molecular X nearly touched those adjacent to it, like XXXXXXX. The same pattern repeated in a perpendicular direction, creating an interlocking fishnet. But these links were held together by weak hydrogen bonds, which meant the meshed material could easily come apart. So, Dichtel and his colleagues added a silicon-based compound that inserted itself at the tips of each pair of Xs, strengthening these attachment points with tougher, more durable covalent bonds and producing a polymer composed of interlocking rings, each of which serves as “mechanical” bond further strengthening the material.

The result, Dichtel and his colleagues report, is strong sheets of interlocking rings. “It’s similar to chainmail in that it cannot easily rip because each of the mechanical bonds has a bit of freedom to slide around,” he says. “If you pull it, it can dissipate the applied force in multiple directions. And if you want to rip it apart, you have to break it in many, many different places.”

When a team of collaborators led by Matthew Becker at Duke University wove just 2.5% of this new material into Ultem—a material made of high-strength fibers in the same family as Kevlar, the resulting fabric’s stiffness increased by nearly 50%. It’s still early days, but “almost every property we have measured has been exceptional in some way,” Dichtel says.

When I was a kid, we would get out the fine china and the the lead crystal for holidays like Thanksgiving and Christmas, and both names struck me as odd, because nothing about the nice plates seemed Chinese, and the nice glasses were obviously glass, not lead. Fine porcelain of course did come from China originally, and lead crystal does contain lead, even if that’s obviously a bad idea:

Lead glass, commonly called crystal, is a variety of glass in which lead replaces the calcium content of a typical potash glass. Lead glass contains typically 18–40% (by mass) lead(II) oxide (PbO), while modern lead crystal, historically also known as flint glass due to the original silica source, contains a minimum of 24% PbO. Lead glass is often desirable for a variety of uses due to its clarity. In marketing terms it is often called crystal glass.

The term lead crystal is, technically, not an accurate term to describe lead glass, because glass lacks a crystalline structure and is instead an amorphous solid. The use of the term remains popular for historical and commercial reasons, but is sometimes changed to simply crystal because of lead’s reputation as a toxic substance. It is retained from the Venetian word cristallo to describe the rock crystal (quartz) imitated by Murano glassmakers.

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The addition of lead oxide to glass raises its refractive index and lowers its working temperature and viscosity. The attractive optical properties of lead glass result from the high content of the heavy metal lead. Lead also raises the density of the glass, being over 7 times as dense as calcium.

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The brilliance of lead crystal relies on the high refractive index caused by the lead content. Ordinary glass has a refractive (n) of 1.5, while the addition of lead produces a range up to 1.7[1] or 1.8.[6] This heightened refractive index also correlates with increased dispersion, which measures the degree to which a medium separates light into its component wavelengths, thus producing a spectrum, just as a prism does. Crystal cutting techniques exploit these properties to create a brilliant, sparkling effect as each cut facet in cut glass reflects and transmits light through the object.

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When tapped, lead crystal makes a ringing sound, unlike ordinary glasses. The wine glasses were always valued also for their “ring” made by the clinking glasses. The sound was better when large quantity of the lead oxide was present in the glassmaking material, like in the British and Irish wine glasses of the 17th-19th centuries with their “rich bell-notes of F and G sharp”.

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George Ravenscroft (1618–1681) was the first to produce clear lead crystal glassware on an industrial scale. The son of a merchant with close ties to Venice, Ravenscroft had the cultural and financial resources necessary to revolutionise the glass trade, setting the basis from which England overtook Venice and Bohemia as the centre of the glass industry in the eighteenth and nineteenth centuries.

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The amount of lead released from lead glass increases with the acidity of the substance being served. Vinegar, for example, has been shown to cause more rapid leaching compared to white wine, as vinegar is more acidic. Citrus juices and other acidic drinks leach lead from crystal as effectively as alcoholic beverages. Daily usage of lead crystalware (without longer-term storage) was found to add up to 14.5 ?g of lead from drinking a 350ml cola beverage.

The amount of lead released into a food or drink increases with the amount of time it stays in the vessel. In a study performed at North Carolina State University, the amount of lead migration was measured for port wine stored in lead crystal decanters. After two days, lead levels were 89 ?g/L (micrograms per liter). After four months, lead levels were between 2,000 and 5,000 ?g/L. White wine doubled its lead content within an hour of storage and tripled it within four hours. Some brandy stored in lead crystal for over five years had lead levels around 20,000 ?g/L.

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It has been proposed that the historic association of gout with the upper classes in Europe and America was, in part, caused by the extensive use of lead crystal decanters to store fortified wines and whisky.

A recent study led by a petroleum geochemist at the U.S. Geological Survey suggests that 5.6 trillion metric tons of hydrogen gas could be buried beneath the Earth’s surface in rocks and underground reservoirs:

The study published in Science Advances predicts a wide range of values for the potential in-place hydrogen resource (103 to 1010 million metric tons (Mt)) with the most probable value of ~5.6 × 10⁶ Mt. Although most of this hydrogen is likely to be impractical to recover, a small fraction or two percent (e.g., 1 × 10⁵ Mt) would supply the projected hydrogen needed to reach net-zero carbon emissions for ~200 years.

This amount of hydrogen contains more energy (~1.4 × 10¹⁶ MJ) than all proven natural gas reserves on Earth (~8.4 × 10¹⁵ MJ).

A research team at Kumamoto University, led by Visiting Associate Professor Hiroshi Tateishi and Professor Eiichi Araki, has identified HPH-15 as a promising alternative to existing diabetes medications like metformin:

The study, published in Diabetologia, a top journal in the field of diabetes, demonstrates that HPH-15 outperforms metformin by activating AMP-activated protein kinase (AMPK) — a critical protein regulating energy balance — at lower doses. HPH-15 not only improved glucose uptake in liver, muscle, and fat cells but also significantly reduced fat accumulation in high-fat diet (HFD)-induced obese mice. Unlike metformin, HPH-15 exhibited additional antifibrotic properties, potentially addressing liver fibrosis and other complications often seen in diabetes patients.

All bacon is cured, but some is labeled uncured:

“Curing is the addition of salt to a product to change the chemical properties in a way that preserves it,” says Moskowitz. The salt in the brine prevents the growth of certain kinds of bacteria that cause meat to spoil. Curing also imparts flavor to the meat. In addition to salt, often sugar, herbs, or spices are added to the brine for flavor.

Both cured and uncured bacon start as slabs of pork belly that are either injected with a wet brine — a saltwater solution — or placed into a wet brine. Some bacon is still made using a dry brine — a dry salt and seasoning mixture — but wet brines are more common.

Smoking meat is also a way of preserving it, and most bacon is smoked over a low temperature after being cured to help further dehydrate the meat, and to impart a nice smoky flavor.

Bacon is most often cured using artificial nitrites, a chemical additive that preserves the meat and gives bacon its pink color. The bacon at Foster Sundry is cured in-house using pink curing salt (it’s not the same thing as Himalayan pink salt), a mixture of sodium chloride (table salt) and sodium nitrite. Pink salt is also known as Prague powder, Insta Cure #1, or pink curing salt #1, and it is commonly used to cure meats, like corned beef.

“There’s a more attractive color on a cured product,” says Moskowitz, “especially when it’s been cured with pink salt.” That’s a large part of the reason butchers prefer cured bacon. When exposed to air, cured bacon maintains its pink color much longer than uncured bacon, which can quickly turn gray.

There isn’t such a thing as “uncured” when it comes to bacon. “It’s misleading,” says Moskowitz. “Most things that are labeled as uncured have had celery salt added to it.”

Celery salt, which contains naturally occurring nitrites, cures the bacon. Bacon labeled as uncured was cured without artificial nitrites like pink salt.

The USDA rules require uncured bacon to be labeled as “no nitrites or nitrates added.” Nitrites are naturally occurring both in our bodies as well as in many foods like celery, lettuce, spinach, and beets. Celery salt and sea salt are two natural nitrates often used to cure meat.