Chemists grow a crystal they had chased for thirty years, Mercosur opens to Singapore one member at a time, and America's hospitals turn back infections

The difficulty lives in the chemical bond. Growing a nanocrystal from solution depends on atoms attaching and detaching at the crystal's surface until an ordered lattice forms, a give-and-take that needs bonds loose enough to rearrange.[3] The bond between a metal and nitrogen is unusually strong and stiff, so the atoms lock into place too firmly to reshuffle, and roughly three decades of attempts to make nitride nanocrystals in a flask came to little.[1][3]

What the pressure does01

The team, led by the chemist Dmitri Talapin, dissolved the ingredients in a bath of molten salt rather than an ordinary solvent, then held the mixture at a set temperature under a high partial pressure of ammonia, the gas that supplies the nitrogen.[1] That combination briefly weakens the metal–nitrogen bond just enough for atoms to find their places and settle into a regular crystal.[1] Working this way, the researchers grew nanocrystals of gallium nitride and of titanium, niobium and molybdenum nitrides, hard and heat-resistant compounds used in coatings and, in some cases, superconductors.[1][2] Talapin put the counterintuitive move plainly, saying it "goes against every bit of common sense in the field."[2]

What the work delivers is a demonstrated method and characterised crystals, not finished devices.[3] The uses the authors point to, inks that could print electronics, flexible lighting, nitride particles folded into polymers or fabrics, remain projections that others will have to build and test.[2][4] The nearer value is as a tool. A family of technologically important materials that solution chemistry could not previously touch is now, in principle, open to the same cheap and versatile handling that once transformed the semiconductor dots already lighting our screens.[1][3]

Brazil has ratified its part of the Mercosur–Singapore trade agreement, and on 1 August 2026 the deal entered into force for the bloc's largest economy, more than two years after it was signed.[1][3] It is the first trade deal between the South American customs union and a Southeast Asian country, and Brazil's entry is what gives it weight, because Brazil accounts for the great majority of the bloc's economic output.[1][3]

The accord takes hold one member at a time rather than all at once, and that sequencing is the mechanism that makes it unusual.[2] Mercosur binds its members, Argentina, Brazil, Paraguay and Uruguay, behind a common external tariff, but each government ratifies this deal on its own timetable, and it enters into force bilaterally with Singapore as each does.[2][4] Paraguay and Uruguay went first, in February and March; Brazil has now followed; Argentina has yet to complete ratification.[4]

Under the terms, Singapore drops its tariffs on all goods from Mercosur countries immediately, while Mercosur phases out duties on about 96 percent of tariff lines, roughly a quarter of them at once and the rest over as long as fifteen years.[2] The text reaches past tariffs into services, digital commerce, government procurement, investment and small-business provisions, and it lets traders attest to the origin of their own goods rather than file standard certificates, a lighter customs step than Mercosur has usually required.[1][2] Whether the pact measurably shifts trade or draws new investment cannot yet be known, and Argentina's eventual decision will settle whether the bloc meets Singapore with one voice or several.[2][4]

The figure comes from a point-prevalence survey, a method that inspects every patient on a set of wards on a single day and counts who has an infection, giving a snapshot rather than a running tally.[1] Investigators reviewed records for 13,653 patients across 218 hospitals in ten states, using standard national definitions, and among the hospitals that took part in both the 2015 and 2023 rounds the adjusted risk of infection was about 27 percent lower in the later year.[1][3]

The improvement is concentrated where hospitals have aimed their prevention effort.[3] Bloodstream infections tied to central lines, urinary-tract infections tied to catheters, and gut infections from Clostridioides difficile, a bacterium that flourishes when antibiotics clear away its competitors, all fell; infections at surgical sites and cases of pneumonia did not shift by a margin the survey could separate from chance.[1][3]

The progress has a ceiling built into it.[1] The survey still points to an estimated 518,000 hospital-acquired infections in 2023, and about 61 percent of them were tied to no device or procedure at all, the harder cases that insertion checklists and sterile-technique protocols do not reach.[1][4] Specialists reading the results caution that even holding this line depends on hospitals keeping infection-prevention staff and budgets intact, the sort of unglamorous investment that erodes quietly when attention moves elsewhere.[3][4]