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The theranostic pair mercury-197m and mercury-197g (197m/gHg, t1/2 = 23.8 h/64.14 h), through their γ rays and Meitner–Auger electron emissions, have potential use as constituents in radiopharmaceuticals to treat small metastatic tumours. However, the use of this pair of nuclear isomers in radiopharmaceuticals requires the development of suitable [197m/gHg]Hg2+ chelators as currently there is a lack of established ligands for radiometals in the field. Herein, this work studies the natHg/197m/gHg coordination of three thiacrown 18-membered N2S4 macrocycles with pendant arms of varying chemical "softness". Following the synthesis and characterization of the N2S4 ligand series (6,6′-((1,4,10,13-tetrathia-7,16-diazacyclooctadecane-7,16-diyl)bis(methylene))dipicolinic acid (N2S4-Pa), 7,16-bis(pyridin-2-ylmethyl)-1,4,10,13-tetrathia-7,16-diazacyclooctadecane (N2S4-Py) and 7,16-bis(2-(methylthio)ethyl)-1,4,10,13-tetrathia-7,16-diazacyclooctadecane (N2S4-Thio)), Hg2+ complexes were studied through mass spectrometry, nuclear magnetic resonance (NMR) spectroscopy, and density functional theory (DFT) calculations, revealing successful complexation of all ligands with the Hg2+ ion. Radiolabeling studies demonstrated the effect of the pendant arm on [197m/gHg]Hg2+ coordination, as N2S4-Thio and N2S4-Py had the highest radiochemical yield, similar to that of previously reported N-benzyl-2-(1,4,7,10-tetrathia-13-azacyclopentadecan-13-yl)acetamide (NS4-BA), while N2S4-Pa had the lowest. The complex integrity of [197m/gHg][Hg(N2S4-Py)]2+ and [197m/gHg][Hg(N2S4-Thio)]2+ in both human serum and glutathione was notably lower compared to the [197m/gHg][Hg(NS4-BA)]2+ complex. However, the [197m/gHg][Hg(N2S4-Py)]2+ and [197m/gHg][Hg(N2S4-Thio)]2+ complexes remained above 70% intact over 82 h when competed against biologically relevant metals (ZnCl2, FeCl3, CuCl2, MgCl2 and CoCl2), suggesting the selectivity of the ligands for Hg2+. This study illustrates the importance of the macrocyclic backbone size and electron-donor groups of the donor pendant arms in the design of chelators for 197m/gHg-radiopharmaceuticals, as both affect the radiolabeling properties and complex inertness. [ABSTRACT FROM AUTHOR]

Sheet pendants made of silver or copper alloy were worn in Estonia from the 10th to the 17th century. This type of jewelry spread to Estonia from Scandinavia and was also used in Finland, Karelia, Latvia, Lithuania, in the areas inhabited by the Baltic tribes in northeastern Poland, and to a lesser extent in northwestern Russia. The symbols depicted on the sheet pendants are Christian. The three dominant symbols are the cross, representing the Christian faith; a boss or circle, symbolizing God the Father; and five bosses arranged in the shape of crosses, representing the Five Holy Wounds of Christ. The 10th-13th-century sheet pendants include looped squares, which are symbols of St. John the Baptist. The 13th-century circular sheet pendants have a design formed by three volutes, symbolizing the Holy Trinity, triskele, swastika, pentagram, and star. Trapezoidal sheet pendants from the 13th century may have been intended as axe shapes, possibly related to the cult of St. Olaf. The meaning of the volutes and interlace patterns on the trapezoidal sheet pendants is unknown. Recognizable Christian symbols on them include the cross of St. Peter and an anchor. In the 15th-17th centuries, new designs include the Maltese cross and the T-shaped cross of St. Anthony. Sheet pendants not only manifested the wearer's Christian faith but also expressed specific central themes and concepts of Christianity. The pendants reflect themes such as God the Father, the birth and crucifixion of Christ, the Holy Trinity, and the sacraments of baptism and the Eucharist. Rinnalehed on hõbe- või vasesulamist valmistatud plekkripatsid, mida kanti Eestis 10.-17. sajandil. See ehtetüüp levis Eestisse Skandinaaviast. Rinnalehed olid kasutusel ka Soomes, Karjalas, Läti ja Leedu aladel, balti höimude poolt asustatud aladel Kirde-Poolas ning vähesel hulgal Loode-Venemaal. Olen jaga- nud Eesti rinnalehed teostuse ja leiukonteksti poolest kaheks: 10.-13. sajandi (223 tk) ja 14.-17. sajandi rinnalehed (898 tk). Rinnalehtedel kujutatud sümbolid on kristlikud. Neil domineerivad kolm sümbolit: kristlikku usku väljendav rist, üks Jumalat tähistav kühm või ring ning viis ristikujuliselt asetatud kühmu, mis kujutavad Kristuse viit püha haava. Möle- mast perioodist pärinevatel rinnalehtedel leidub ka riste, mille harude ots- tesse on paigutatud kolm kühmukest, mis sümboliseerivad Püha Kolmainsust. 10.-13. sajandi rinnalehtedel leidub silmusristi, mis on Ristija Johannese sümbol, ning 10.-11. sajandi rinnalehtedel ka ristikujuliste otstega riste, mis töenäoli- selt väljendasid kristlikku misjonitegevust. 13. sajandi ringikujulistel rinna- lehtedel esineb voluudist koosnevat kujundit, mis viitab Pühale Kolmainsusele, ning triskelet, haakristi, viisnurka ja tähte. 13. sajandi trapetsikujulised rinnalehed võivad olla möeldud kirvekujulistena, väljendades Püha Olavi kultust. Trapetsi- kujulistel rinnalehtedel kujutatud voluutide ja pöimornamendi tähendus ei ole teada. Äratuntavad kristlikud märgid neil on Püha Peetruse rist ja ankur. 14.-17. sajandi rinnalehed on küll varasematest suuremad ja arvukamad, kuid sümbolite valik nendel on piiratum: neil on enamasti rist ja viis kühmu või üks kühm, kus- juures enamikul juhtudel on kujutatud korraga risti ja viit kühmu. Selle ajastu rinnalehtedel on enim levinud Kristuse viie haava sümbol. Haakrist esineb kesk- ja varauusaegsetel rinnalehtedel vaid üksikjuhtudel. 15.-17. sajandil lisandusid rinnalehtede kujundusse Malta rist ja T-tähe kujuline Püha Antoniuse rist. Rinnalehed manifesteerisid oma kandja kristlikku usku ning väljendasid kindlaid ristiusu teemasid ja möisteid. Rinnalehtedel kajastuvad Jumal Isa, Kristuse sünd ja ristisurm, Püha Kolmainsus ja ristimise sakrament. [ABSTRACT FROM AUTHOR]

[Display omitted] • A bipyridine containing homopolymer is synthesized to prepare various nanostructures via different self-assembly pathways. • Bowl-shaped nanoparticles with controlled size and openings are obtained by controlling the initial concentration. • A fusion induced assembly behavior is found to form nanosheets using nanowires as building block. The control of the morphology and nanostructure of soft nanomaterials self-assembled from amphiphilic polymers has attracted significant attention. In this study, various nanostructures including bowl-shaped nanoparticles with controlled openings, round Yuanbao-shaped assemblies, nanowires and butterfly shaped twin nanosheets are formed by manipulating the self-assembly pathway of an amphiphilic homopolymer. The amphiphilic (poly(N -(2,2′-bipyridyl-4-acrylamide), PBPyAA) with bipyridine pendants is designed and synthesized by reversible addition fragmentation chain transfer (RAFT) polymerization, which can self-assemble into bowl-shaped nanoparticles with controlled openings by solvent switch method at different initial concentrations. In addition, core–shell nanostructures are obtained taking advantage of the coordination between bipyridine and Fe2+. Upon annealing in ethanol, butterfly shaped twin nanosheets with thickness of about 10 nm are formed by controlling the cooling rate, while round Yuanbao-shaped assemblies are formed by naturally cooling. Revealing into the formation mechanism of the butterfly shaped twin nanosheets, a fusion induced assembly process of nanowires is observed. Overall, various nanostructures are obtained by manipulating the self-assembly pathways of a bipyridine containing amphiphilic homopolymer. [ABSTRACT FROM AUTHOR]

Background: Cellulose polymers with multidentate chelating functionalities that have high efficiency for toxic metal ions present in water were designed, synthesized, and analyzed. The synthesis was carried out by reacting microcrystalline cellulose extracted from the solid waste of the olive industry with tert-Butyl acetoacetate (Cell-AA), produced cellulose with β-ketoester functionality was then reacted with aniline and the amino acid glycine to produce Cell-β-AN and Cell-β-GL, respectively. Results: The adsorption efficiency of the three polymers toward Pb(II) and various toxic metal ions present in sewage was evaluated as a function of adsorbent dose, time, temperature, pH value, and initial ion concentration to determine optimum adsorption conditions. The three polymers showed excellent efficiency toward about 20 metal ions present in a sewage sample collected from the sewer. The adsorption process follows the Langmuir adsorption isotherm model with a second-order of adsorption rate, the calculated qe values (2.675, 15.252, 20.856 mg/g) were close to the experimental qe values (2.133, 13.91, 18.786 mg/g) for the three polymers Cell-AA, Cell-β-AG and Cell-β-AN, respectively. Molecular Dynamic (MD) and Monte Carlo (MC) simulations were performed on the three polymers complexed with Pb(II). Conclusion: The waste material of the olive industry was used as a precursor for making the target cellulose polymers with β-Amino Ester Pendant Group. The polymer was characterized by SEM, proton NMR, TGA, and FT-IR spectroscopy. The efficacy of adsorption was quantitative for metal ions present in a real sample of wastewater and the efficiency didn't drop even after 7 cycles of use. The results indicate the existence of strong complexation. The thermodynamic study results showed a spontaneous bonding between of Pb(II) and the polymers pendant groups expressed by the negative value of the Gibbs free energy. [ABSTRACT FROM AUTHOR]