Rare Earth Nitrate Hybrid Double Perovskites [Me4N]2[MLn(NO3)6] (M = Na-Cs; Ln = La-Gd, ex. Pm).

An exploration of the synthetic and structural phase space of rare earth hybrid double perovskites A2B'BX6 (A = organocation, B' = M+, B = M3+, X = molecular bridging anion) that include X = NO3- and B' = alkali metal is reported, complementing earlier studies of the [Me4N]2[KB(NO3)6] (B = Am, Cm, La-Nd, Sm-Lu, Y) (Me4N = (CH3)4N+) compounds. In the present efforts, the synthetic phase space of these systems is explored by varying the identity of the alkali metal ion at the B'-site. Herein, we report three new series of the form [Me4N]2[B'B(NO3)6] (B = La-Nd, Sm-Gd; B' = Na, Rb, Cs). The early members of the Na-series crystallize in the trigonal space group R3̅ from La to Nd where a phase transition occurs in the phase between 273 and 300 K, going from R3̅ to the high-symmetry, cubic space group Fm3̅m. The preceding trigonal members of the Na-series also undergo phase transitions to cubic symmetry at temperatures above 300 K, establishing a decreasing trend in the phase-transition temperature. The remainder of the Na-series, as well as the Rb- and Cs-series, all crystallize in Fm3̅m at 300 K. The temperature-dependent phase behavior of the synthesized phases is studied via variable-temperature spectroscopic methods and high-resolution powder X-ray diffractometry. All phases were characterized via single-crystal and powder X-ray diffraction and Fourier transform infrared (FT-IR) and Raman spectroscopic methods. These results demonstrate the versatility of the perovskite structure type to include rare earth ions, nitrate ions, and a suite of alkali metal ions and serve as a foundation for the design of functional rare earth hybrid double perovskite materials such as those possessing useful multiferroic, optical, and magnetic properties.

Novel Heterometallic Uranyl-Transition Metal Materials: Structure, Topology, and Solid State Photoluminescence Properties.

Six new uranyl hybrid materials have been synthesized solvothermally utilizing the ligands 2,2'-bipyridine-3,3'-dicarboxylic acid (H2L) and 2,2':6',2''-terpyridine (TPY). The six compounds are classified as either molecular complexes (I0O0 connectivity), [(UO2)(L)(TPY)]·H2O (1), [Ni(TPY)2][(UO2)(L)2]·3H2O (2), and [Cu(TPY)2][(UO2)(L)2]·3H2O (3), or 3D metal-organic frameworks (MOFs, I0O3 connectivity), [Cu2(UO2)2(OH)(C2H3O2)(L)3(TPY)2]·6H2O (4), [Zn2(UO2)2(OH)(NO3)(C2H3O2)(L)3(TPY)2]·4H2O (5), and Na[Ni(UO2)3(OH)(O)(L)3]·9H2O (6). A discussion of the influence of transition metal incorporation, chelating effects of the ligand, and synthesis conditions on the formation of uranyl materials is presented. The structure of compound 6 is of particular note due to large channel-like voids with a diameter of approximately 19.6 Å. A topological analysis of 6 reveals a new topology with a 9-nodal 3,3,3,3,3,3,3,4,5-connected network, designated geg1 hereafter. Further, solid state photoluminescence experiments show emission and lifetimes values consistent with related uranyl compounds.

A novel symmetric pyrazine (pyz)-bridged uranyl dimer [UO2Cl3(H2O)(Pyz)0.5]22-: synthesis, structure and computational analysis.

Herein we report on the synthesis of (HPyz+)2[UO2Cl3(H2O)(Pyz)0.5]2·2H2O which features a novel pyrazine-bridged uranyl dimer, [UO2Cl3(H2O)(Pyz)0.5]22-. A rigorous computational and experimental analysis of this compound was performed to fully explore the influence of coordination on the electronic structure and potential charge-transfer characteristics of this dimer, revealing a delocalized π-system across the bridging pyrazine and the axial components of both uranyl centers. Electrostatic surface potentials, used to rationalize the observed assembly, indicate a decreased basicity of the uranyl oxo versus [UO2Cl4]2-, and signify a lessened capacity for the terminal -yl oxos of the [UO2Cl3(H2O)(Pyz)0.5]22- dimer to participate in supramolecular assembly. A combined density functional theory (DFT) and quantum theory of atoms in molecules (QTAIM) analysis further evidenced an increase in UO bond strengths within the dimer, which is supported by a blue shift in the characteristic Raman-active uranyl symmetric stretch (ν1) with respect to the more typically observed [UO2Cl4]2-.

Sex disparities in lung cancer survival rates based on screening status.

OBJECTIVE: Low dose computed tomography (LDCT) became the standard method for lung cancer (LC) screening in 2013. However, it is unclear whether there are differences in survival rates based on sex and whether the differences depend on screening status. We aimed to evaluate the LC survival rates between females and males based on screening. MATERIAL AND METHODS: This retrospective cohort study examined data from the Boston LC Study (BLCS) between 2013 and 2021. LC screening depends on patients' demographics (age and smoking history) to determine whether a person is a high-risk individual and, therefore, undergo LDCT. Descriptive statistics were calculated for race, age, histology, smoking history, stage, and treatment. These variables' distributions were compared between sex and screening status using t-test and chi-square, respectively. Cox proportional hazards model and Kaplan-Meier curves were used to compare survival between sex and screening. Propensity score matching was applied to account for selection bias in screening when evaluating the association between screening and stage. RESULTS: A total of 1,216 LC patients were identified with a screening incidence of 9.4 %, among whom 56 % were female. Unscreened males had 1.59 times higher risk of mortality than unscreened females (P=.0002) and had a worse 5-year survival (male 50 %; 95 %CI, 0.38,0.6 vs female 70 %; 95 %CI,0.62,0.76). In contrast, there were no significant differences in survival between sexes among screened. In a balanced cohort of screened and unscreened, the odds of being diagnosed at late stages for females and smokers were 1.33 and 2.51 times that of males and nonsmokers; however, there were no statistical significance. CONCLUSION: Unscreened females had a lower risk of mortality and better survival than unscreened males, while among the screened population, there was no difference in the overall survival. These observations demonstrate the influence of sex on survival prognosis in LC when screening is not performed.

Bimetallic uranyl/cobalt(II) isothiocyanates: structure, property and spectroscopic analysis of homo- and heterometallic phases.

We report the synthesis and characterization of a family of UO22+/Co2+ isothiocyanate materials containing [UO2(NCS)5]3- and/or [Co(NCS)4]2- building units charged balanced by tetramethylammonium cations and assembled via SS or SOyl non-covalent interactions (NCIs), namely (C4H12N)3[UO2(NCS)5], (C4H12N)2[Co(NCS)4], and (C4H12N)5[Co(NCS)4][UO2(NCS)5]. The homometallic uranyl phase preferentially assembles via SS interactions, whereas in the heterometallic phase SOyl interactions are predominant. The variation in assembly mode is explored using electrostatic surfaces potentials, revealing that the pendant -NCS ligands of the [Co(NCS)4]2- anion is capable of outcompeting those of the [UO2(NCS)5]3- anion. Notably, the heterometallic phase displays atypical blue shifting of the uranyl symmetric stretch in the Raman spectra, which is in contrast to many other compounds featuring non-covalent interactions at uranyl oxygen atoms. A combined experimental and computational (density functional theory and natural bond orbital analyses) approach revealed that coupling of the uranyl symmetric stretch with isothiocyanate modes of equatorial -NCS ligands was responsible for the atypical blue shift in the heterometallic phase.