Cuff-Free Blood Pressure Monitoring Moves Closer to Reality
A laser-based technique that tracks blood flow and volume in real time could pave the way for wearable, cuff-free blood pressure monitors – offering a more accurate and comfortable alternative to standard methods. The technology, called speckle contrast optical spectroscopy (SCOS), measures subtle changes in laser light scattering as it interacts with moving blood cells beneath the skin.
Tested on 30 volunteers, SCOS delivered systolic blood pressure estimates with an error margin as low as 2.26 mmHg, outperforming traditional optical methods by up to 31 percent. Unlike photoplethysmography – the basis for most current optical monitors – SCOS simultaneously captures both blood volume and flow, providing richer cardiovascular insights from simple measurements at the wrist or finger.
“Hypertension affects nearly half of all adults in the US,” said study co-author Ariane Garrett of Boston University in a press release. “This is a step towards a wearable device that would let people monitor their blood pressure any time, without a cuff.”
The research, published in Biomedical Optics Express, lays the foundation for devices that can track blood pressure throughout the day – a critical advantage for spotting hard-to-detect conditions like masked hypertension. The team’s next goal: a compact, wearable version of the system built for daily use.
Solid-State NMR Cracks the Code of Mixed Plastic Waste
A new solid-state NMR technique can now identify and track the complex chemistry of real-world plastic waste mixtures – enabling precise, guided transformations into high-value products.
Published in Nature, the study showcases how frequency-switched Lee–Goldburg heteronuclear correlation (FSLG-HETCOR) NMR reveals high-resolution “fingerprints” of common plastics like PET, PVC, PLA, and PS, even in tangled, multi-material samples. The method allows researchers to observe functional group evolution in real time, providing a molecular roadmap for catalytic conversion.
Unlike conventional analysis methods, the technique works directly on insoluble materials, making it uniquely suited to study plastic mixtures too complex for solution-based tools. The authors used it to guide a full, stepwise transformation of post-consumer plastics into useful chemicals – a major leap toward scalable, intelligent recycling systems.
The authors believe their “guiding eye” approach could unify fragmented plastic recycling strategies under a single analytical framework.
Sealed Threats: Magnetic Scan Detects Fentanyl Through Opaque Packaging
Fentanyl hydrochloride can be detected inside sealed, opaque packages using nuclear quadrupole resonance (NQR) spectroscopy, according to a new study – offering a fast, contactless method for identifying the deadly opioid without opening a container.
By targeting specific magnetic signatures of nitrogen and chlorine nuclei, scientists identified fentanyl’s unique NQR fingerprint, allowing it to be sensed through common materials like cardboard, plastic, and glass. The system operates at room temperature, requires no sample prep, and could cost just a few thousand dollars to deploy – far cheaper and more portable than existing chemical or Raman-based techniques.
The team behind the work, published in PNAS Nexus, pinpointed two distinct NQR frequencies (3.10 and 3.30 MHz) corresponding to fentanyl’s aniline group. These signals were confirmed through solid-state NMR and computational modeling. The method’s sensitivity drops with thick metallic shielding or distance beyond a few centimeters, but its potential use in mailrooms, airports, or border crossings could be transformative for drug interdiction efforts.
This marks the first known NQR signal reported for a synthetic opioid, and the researchers describe the approach as a critical proof-of-concept for noninvasive narcotics detection.
Sodium Levels Monitored in Real Time – Without a Needle in Sight
A new optical system can noninvasively track blood sodium levels in real time, potentially replacing needle-based tests with a fast, painless alternative. Developed by researchers at Tianjin University and reported in Optica, the approach combines terahertz (THz) spectroscopy with optoacoustic detection to overcome long-standing technical barriers to in vivo sodium monitoring.
Terahertz radiation is ideal for probing biological molecules due to its sensitivity to chemical structure, but water’s strong absorption of THz waves has historically made it difficult to use in living tissues. The team’s solution: a hybrid system that converts THz absorption into sound. When THz waves interact with sodium ions, they generate subtle ultrasound signals – detected by a transducer – that reflect sodium concentration.
In live mouse tests, the system monitored changes in sodium levels in superficial blood vessels with millisecond resolution over 30 minutes. Additional experiments in humans showed it could distinguish sodium concentrations in both blood samples and in vivo skin measurements. Notably, even without skin cooling, the optoacoustic signal still scaled with blood flow under the skin.
This technology could eventually allow clinicians to monitor sodium levels continuously in critical care or outpatient settings – avoiding blood draws and enabling better management of dehydration, kidney disease, or neurological conditions. According to the researchers, it could also be adapted to track other biomolecules with distinct terahertz signatures, such as glucose or proteins. Further development will focus on miniaturization, improved signal processing, and testing in less controlled environments.
Silica Nanoparticles Disrupt Protein Structure
Silica nanoparticles (SiNPs) are widely used in drug delivery and diagnostics, but new research suggests ultra-small versions may pose hidden biological risks. A study in Langmuir reveals that 10-nanometer SiNPs cause bovine serum albumin – a major blood protein – to misfold into β-sheet–rich structures, a hallmark of amyloid diseases like Alzheimer’s.
The Tokyo University of Science team, led by Masakazu Umezawa, analyzed protein–nanoparticle interactions using thioflavin T fluorescence, infrared spectroscopy, and circular dichroism. They found that the smallest SiNPs induced the largest spike in β-sheet formation after just one hour of mixing. Larger SiNPs took longer to cause similar disruptions, likely due to reduced molecular mobility.
The results underscore a potential safety concern: high-curvature nanoparticle surfaces offer more contact points, promoting abnormal protein conformations.
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