gadolinium
Let an agent identify gadolinium and its properties, relay isotopes, production and uses from reference sources, describe MRI contrast agents and their safety in general terms, and distinguish gadolinium from neighbouring lanthanides.
Bundle → Layer → Finding → Questions Filled
4 bundles · 8 layers · 8 findings · 16 questions
Identify What gadolinium is.
Properties
Properties.
Properties
Properties.
- What are the physical, magnetic and nuclear properties of gadolinium? definition
- Is the question about gadolinium or a neighbouring lanthanide? boundary
Isotopes
Isotopes.
Isotopes
Isotopes.
- Which isotopes exist, and which have high neutron capture? definition
- Which entry fits the specific isotope? action
Source Occurrence and production.
Occurrence
Occurrence.
Occurrence
Occurrence.
- Where does gadolinium occur, and how is it separated? provenance
- Which entry fits rare earth mining? action
Supply
Supply.
Supply
Supply.
- Who produces gadolinium, and how is it traded, with sources? measurement
- Which sources are cited? provenance
Use Uses.
Medical
MRI contrast.
Medical
Medical.
- How do gadolinium contrast agents work, and what safety issues have regulators addressed, in general terms? provenance
- Is the user asking about their own scan, which needs a clinician? boundary
Other
Nuclear, magnetic and other uses.
Other
Other.
- How is gadolinium used in neutron shielding, magnetic refrigeration and phosphors? provenance
- Which references are standard? provenance
Context History and environment.
Discovery
Discovery.
Discovery
Discovery.
- How was gadolinium discovered by Marignac in 1880 and named after Johan Gadolin? provenance
- Which entry fits the history of the rare earths? action
Environment
Environmental gadolinium.
Environment
Environment.
- What do studies report about anthropogenic gadolinium in rivers from medical use? provenance
- Which entry fits pharmaceutical pollution? action
Classifiers Filled
- Family
- Thing Registry
- Category
- Physical world and living systems
- Entry kind
- thing
- Plane
- PHY
- Domain
- PHY.MAT
- Other names and narrower kinds
- gadolinium-166, gadolinium-167, gadolinium-134, gadolinium-135, gadolinium-136, gadolinium-137, gadolinium-138, gadolinium-138m, gadolinium-139, gadolinium-139m, gadolinium-140, gadolinium-141
What it is Filled
A chemical element with symbol Gd and atomic number 64, a silvery lanthanide with the highest thermal neutron capture cross-section of any stable element, ferromagnetic below room temperature, obtained from monazite and bastnasite and used in gadolinium-based contrast agents for magnetic resonance imaging, in neutron shielding and reactor control, in magnetic refrigeration research, in phosphors and in alloys; gadolinium has six stable isotopes plus the very long-lived gadolinium-152, with radioactive isotopes from gadolinium-134 upward.
Why it exists Filled
Let an agent identify gadolinium and its properties, relay isotopes, production and uses from reference sources, describe MRI contrast agents and their safety in general terms, and distinguish gadolinium from neighbouring lanthanides.
Distinguishing features Filled
- Highest neutron capture
- Room-temperature Curie point
- MRI contrast use
- Magnetocaloric effect
What robots and AI may and may not do Filled
Must not
- Advise on contrast agent doses or use for a patient in place of a clinician.
- Downplay concerns about gadolinium retention or kidney-related risks from contrast agents.
- Recommend disposal of gadolinium waste outside approved routes.
- Misstate the source or sustainability of rare earth supply.
Only with a human decision
- Deciding to give a gadolinium contrast agent to a patient with kidney disease.
May
- Describe gadolinium's properties and uses in imaging, nuclear and magnetic technology.
- Report safety data sheets and handling rules for gadolinium compounds.
Moral aspects Filled
- Contrast agents help diagnosis but carry risks patients deserve to be told about.
- Rare earth mining causes pollution that falls on local communities.
Who is affected
- Patients
- Communities near rare earth mines
- Workers
Owners Filled
Steward
The holder of the material; regulators for medical products and chemicals.
Master systems
- Chemical substance inventories
- Medicines regulators' product registers
Links to other meta-models Filled
parent
- Q105789 - registry parent class
- Q19569 - registry parent class
related
- lanthanide - in registry terms
- heavy metal - in registry terms
- gadolinium-based contrast agent - for MRI
- terbium - element 65
What else AI and robots need to interact with it Filled
Identity and identifiers required Filled
- Vercy registry: vr.tr.gadolinium
- Wikidata: Q1832 (https://www.wikidata.org/wiki/Q1832)
- symbol: Gd
- CAS: 7440-54-2
Direct properties required Filled
- atomic number: 64 Z
- standard atomic weight: 157.25 u
- Curie temperature: about 20 degrees C
- thermal neutron cross-section: about 49000 barns - natural mixture
Recognition required Filled
- Element 64, symbol Gd
- Lanthanide of MRI contrast and neutron capture
- Europium and terbium are the neighbouring lanthanides
- A silvery metal that tarnishes slowly in dry air.
Capabilities and actions required Filled
- relay properties and isotopes
- explain production and uses
- describe contrast agent safety in general terms
- distinguish from other lanthanides
Hazards and failure modes required Filled
- Nephrogenic systemic fibrosis with some agents in kidney disease
- Gadolinium retention and environmental release
- Confusing with neighbouring lanthanides
Standards and interfaces required Filled
- Drug regulation of gadolinium contrast agents, including restrictions on linear agents
- Chemical safety data sheets
- Nuclear material rules for neutron absorbers
Context of use required Filled
- MRI contrast, neutron capture, magnets and phosphors.
- gadolinium metal and alloys
- gadolinium compounds and chelates for MRI
- stable isotopes from gadolinium-154 to gadolinium-160 and the long-lived gadolinium-152
- radioactive isotopes such as gadolinium-134 to gadolinium-137 and gadolinium-166 and 167
- gadolinium in phosphors and garnets
Sources Filled
- Wikidata item Q1832: gadolinium - identity and sense of the item
- Wikipedia: Gadolinium - general description of the item
Open questions
- Should gadolinium contrast agent be a separate primary entry?
- How should reference and regulatory sources be linked?
- The registry entry has merged aliases naming isotopes; should they be split off?
Machine files
Provenance
thing registry research (pass 2) · unreviewed
Built from: models/things/publications/thing-q1832/spec.json