正在加载视频...

视频加载失败

S-Shaped Herkimer "Diamond" Chain This specimen is unique because it has gemmy Smoky Quartz surrounding a clear Quartz crystal in the center and an aesthetic S-shape. Herkimer "Diamonds" are a variety of Quartz found in Herkimer, New York. These are nicknamed "Diamonds" because of their incredible brilliance and their...

17,963 次观看 • 6 个月前 •via X (Twitter)

0 条评论

暂无评论

原始帖子的评论将显示在这里

相关视频

There's a bacteriophage that turns bacteria into “liquid crystals.” Specifically, Pseudomonas aeruginosa bacteria make Pf phages, which are rod-shaped, negatively-charged, and measure about 2 micrometers in length (roughly the length of an E. coli cell). These phages leave the cells and enter their surroundings. There, they mix with polymers, also secreted by the cells, to form a crystalline matrix. Surprisingly, this is good for the cells. Although the phages kill some of them, it also makes their biofilms stickier and able to withstand certain antibiotics. These bacteria + phages are prevalent in cystic fibrosis patients; they've formed a sort of symbiotic relationship. The Pf phages are made from thousands of repeating copies of a coat protein, called CoaB, which wraps around a single-stranded, circular DNA genome. These genes are integrated directly on the bacterial chromosome. The bacteria “turn on” these phage genes when placed in a viscous environment with low oxygen levels. This is like a trigger to start forming a biofilm. And the cells make a lot of phages; about 100 billion per milliliter. These liquid crystals form because of a physics principle called “depletion attraction.” If you just mix a bunch of loose or flexible polymers together (such as long carbon chains) they will not form a liquid crystal. But if you mix stiff rods (the phages) with loose polymers at a high enough concentration, the polymers will force the phages close together to create a material that flows like a liquid despite being ordered like a crystal. See the video below. These liquid crystal biofilms are hard to get rid of. The negatively-charged phages block many antibiotics (like aminoglycosides, which are positively-charged) from entering cells. Liquid crystals also retain water, so these biofilms can survive on drier surfaces. I first heard about this from Malmesbury’s excellent newsletter, called “Telescopic Turnip.”

Niko McCarty.

50,450 次观看 • 10 个月前

Balochistan’s Daughters — Courage in Service, Strength in Spirit True courage is not found in raising arms against your own people or becoming a pawn of those who seek to spread violence. It is found in serving your homeland, protecting its people and standing firm against terrorism. The brave women serving in Pakistan’s Frontier Corps are living proof that courage has no gender. With discipline, determination and an unshakable sense of duty, they are serving their country and becoming a powerful source of inspiration for the daughters of #Balochistan. Their service reflects the strength, dignity and resilience of Baloch women. They are showing that the daughters of Balochistan can stand at the forefront of their homeland’s defence, contribute with honour and serve #Pakistan with pride. For the daughters of Balochistan, these women are more than uniformed personnel—they are role models. They represent a future where girls can choose education, service, leadership and opportunity; where their strength is used to build, protect and uplift their communities. The daughters of Balochistan deserve a future defined by education, peace, opportunity and progress—not violence, fear or destruction. Let their courage inspire a generation. Let their service become a symbol of what Balochistan’s daughters can achieve when given the opportunity to rise. Balochistan’s daughters are strong. They are capable. They are courageous. And they have a rightful place in the service and progress of Pakistan. Empowered daughters. Fearless women. A stronger Balochistan. A stronger Pakistan.

Bilsum (بِلسم)

14,962 次观看 • 1 个月前