nice trap !

Within touching distance...

The ankh or key of life is an ancient Egyptian hieroglyphic symbol that was most commonly used in writing and in Egyptian art to represent the word for "life" and, by extension, as a symbol of life itself. The ankh has a cross shape but with a teardrop-shaped loop in place of a vertical upper bar.

https://youtu.be/z_aC5xPQ2f4

enclose; 3rd person present: encloses; past tense: enclosed; past participle: enclosed; gerund or present participle: enclosing; verb: inclose; 3rd person present: incloses; past tense: inclosed; past participle: inclosed; gerund or present participle: inclosing; verb: in-close; 3rd person present: in-closes; past tense: in-closed; past participle: in-closed; gerund or present participle: in-closing

1.
surround or close off on all sides.

"the entire estate was enclosed with walls"

surround
circle
ring

From Middle English enclosen, inclosen, from Middle English enclos, from Old French enclose, feminine plural past participle of enclore, from Vulgar Latin *inclaudō, *inclaudere, from Latin inclūdō (doublet of include), from in- (“in”) + claudō (“to shut”), ultimately from Proto-Indo-European *kleh₂u- (“key, hook, nail”). Equivalent to en- +‎ close.

include (third-person singular simple present includes, present participle including, simple past and past participle included)

clue (plural clues)

(now rare) A strand of yarn etc. as used to guide one through a labyrinth; something which points the way, a guide.

Information which may lead one to a certain point or conclusion.

Give me a clue because the question is too vague.
An object or a kind of indication which may be used as evidence.

The decetives were looking for some clues at the scene of the crime.

Insight or understanding ("to have a clue [about]" or "to have clue". See have a clue, clue stick)
I had little clue that I was being carefully monitored by the CCTV.

Synonyms
(information which may lead one to a certain point or conclusion): hint, indication, suggestion

(object or indication which may be used as evidence): signature

(understanding): idea

late Middle English (in idea (sense)): via Latin from Greek idea ‘form, pattern’, from the base of idein ‘to see’.

Ocular ultrasound, also known as ocular echography, "echo," or a B-scan, is a quick, non-invasive test routinely used in clinical practice to assess the structural integrity and pathology of the eye.

QDs are sometimes called 'artificial atoms'. If they are injected into the eye, they settle in the retina, the light-sensing layer of cells that is damaged by RP. When light enters the eye, it is absorbed by the QDs in the retina, and the light energy is converted to electrical energy.

https://mdpi-res.com/d_attachment/pharmaceutics/pharmaceutics-13-02073/article_deploy/pharmaceutics-13-02073-v2.pdf

Abstract: Quantum dots (QDs) are a promising tool to detect and monitor tumors. However, their
small size allows them to accumulate in large quantities inside the healthy cells (in addition to the tumor cells), which increases their toxicity. In this study, we synthesized stealth liposomes encapsulating hydrophilic graphene quantum dots and triggered their release with ultrasound with the goal of developing a safer and well-controlled modality to deliver fluorescent markers to tumors. Our results confirmed the successful encapsulation of the QDs inside the core of the liposomes and showed no effect on the size or stability of the prepared liposomes.

Our results also showed that low-frequency ultrasound is an effective method to release QDs encapsulated inside the liposomes in a spatially and temporally controlled manner to ensure the effective delivery of QDs to tumors while reducing their systemic toxicity.