Microwave Ablation versus Surgical Resection for US-detected Multifocal T1N0M0 Papillary Thyroid Carcinoma: A 10-Center Study.

Background Microwave ablation (MWA) is currently under preliminary investigation for the treatment of multifocal papillary thyroid carcinoma (PTC) and has shown promising treatment efficacy. Compared with surgical resection (SR), MWA is minimally invasive and could preserve thyroid function. However, a comparative analysis between MWA and SR is warranted to draw definitive conclusions. Purpose To compare MWA and SR for preoperative US-detected T1N0M0 multifocal PTC in terms of overall and 1-, 3-, and 5-year progression-free survival rates and complication rates. Materials and Methods In this retrospective study, 775 patients with preoperative US-detected T1N0M0 multifocal PTC treated with MWA or SR across 10 centers between May 2015 and December 2021 were included. Propensity score matching (PSM) was performed for patients in the MWA and SR groups, followed by comparisons between the two groups. The primary outcomes were overall and 1-, 3-, and 5-year progression-free survival (PFS) rates and complication rates. Results After PSM, 229 patients (median age, 44 years [IQR 36.5-50.5 years]; 179 female) in the MWA group and 453 patients (median age, 45 years [IQR 37-53 years]; 367 female) in the SR group were observed for a median of 20 months (range, 12-74 months) and 26 months (range, 12-64 months), respectively. MWA resulted in less blood loss, shorter incision length, and shorter procedure and hospitalization durations (all P < .001). There was no evidence of differences in overall and 1-, 3-, or 5-year PFS rates (all P > .05) between MWA and SR (5-year rate, 77.2% vs 83.1%; P = .36) groups. Permanent hoarseness (2.2%, P = .05) and hypoparathyroidism (4.0%, P = .005) were encountered only in the SR group. Conclusion There was no evidence of a significant difference in PFS rates between MWA and SR for US-detected multifocal T1N0M0 PTC, and MWA resulted in fewer complications. Therefore, MWA is a feasible option for selected patients with multifocal T1N0M0 PTC. © RSNA, 2024 Supplemental material is available for this article. See also the editorial by Georgiades in this issue.

Theoretical insights into selective extraction of Am(III) from Cm(III) and Eu(III) with asymmetric N-heterocyclic ligands.

Separation of lanthanide (Ln) and minor actinide (MA) elements and mutual separation between minor actinide elements (e.g. Am(III) and Cm(III)) represent a crucial undertaking. However, separating these elements poses a significant challenge owing to their highly similar physicochemical properties. Asymmetric N-heterocyclic ligands such as N-ethyl-6-(1H-pyrazol-3-yl)-N-(p-tolyl)picolinamide (Et-p-Tol-A-PzPy) and N-ethyl-N-(p-tolyl)-1,10-phenanthroline-2-carboxamide (ETPhenAm) have recently received considerable attention in the separation of MAs over Ln from acid solutions. By changing the central skeleton structures of these ligands and introducing substituents with different properties on the side chains, their complexation behavior with Am(III), Cm(III), and Eu(III) may be affected. In this work, we explore four different asymmetric N-containing heterocyclic ligands, namely Et-p-Tol-A-PzPy (L1), N-ethyl-6'-(1H-pyrazol-3-yl)-N-(p-tolyl)-[2,2'-bipyridine]-6-carboxamide (L2), N-ethyl-9-(1H-pyrazol-3-yl)-N-(p-tolyl)-1,10-phenanthroline-2-carboxamide (L3), and ETPhenAm (L4) using density functional theory (DFT). The calculated results demonstrate the potential of ligands L1-L4 for the extraction and separation of Am(III), Cm(III), and Eu(III). Ligand analysis shows that ligand L3 binds more easily to the central metal atom, in line with the stronger extraction capacity of L3. In spite of the higher covalence between the side chain and the central metal atom for complexes with L1-L3, the main chain seems to control the stability of the extraction complexes. The preorganized 1,10-phenanthroline backbone also further enhances the extraction performance of L3 and L4. The difference in coordination ability between the side chain donors of these ligands and metal ions may affect their separation efficiency. This work presents theoretical insights into synthesizing novel ligands for separating trivalent actinides by adjusting N-heterocyclic ligands.

Ultrasound-guided microwave ablation versus surgery for solitary T1bN0M0 papillary thyroid carcinoma: a prospective multicenter study.

OBJECTIVE: Microwave ablation (MWA) has emerged as a minimally invasive technology for papillary thyroid microcarcinoma (PTMC), but it has not been widely applied to treat T1bN0M0 PTC with high-level evidence. This study was designed to compare the real-world efficacy and safety of MWA or surgery for treating T1bN0M0 PTC. METHODS: From December 2019 to April 2021, 123 continuous unifocal T1bN0M0 PTC patients without lymph node metastasis (LNM) or distant metastasis (DM) were included from 10 hospitals. Patients were allocated into the MWA or surgery group based on their willingness. The main outcomes were local tumour progression (LTP), new thyroid cancer, LNM, and DM. The secondary outcomes included changes in tumour size and volume, complications, and cosmetic results. Subgroup analyses were conducted to identify influencing factors. RESULTS: Fifty-two patients chose MWA, and 71 patients chose surgery. Patients had similar demographic information and tumour characteristics in the two groups. The follow-up durations after MWA and surgery were 10.6 ± 4.2 and 10.4 ± 3.4 months, respectively. The LNM rate was 5.8% in the MWA group and 1.4% in the surgery group (p = 0.177). No LTP, new thyroid cancer, or distant metastasis (DM) occurred in either group. Five (9.6%) of the 52 patients in the MWA group and 8 (11.3%) of the 71 patients in the surgery group had complications (p = 0.27). Better cosmetic results were found in the MWA group (p < 0.01). CONCLUSION: MWA achieved comparable short-term treatment efficacy with surgery. MWA might be an optional choice for surgery for low-risk T1bN0M0 PTC but concerns about LNM need to be studied further. CLINICAL RELEVANCE STATEMENT: MWA achieved comparable short-time treatment efficacy with surgery. MWA might be an optional choice for surgery for low-risk T1bN0M0 PTC. KEY POINTS: • MWA achieved comparable short-term treatment efficacy with surgery. MWA might be an optional choice for surgery for low-risk T1bN0M0 PTC but concerns about LNM need to be studied further. • The complication rate in the surgery group was higher than that in the MWA group without a significant difference. • There was no statistically significant difference in the LNM rate between the MWA and surgery groups.

Heterocyclic Ligands with Different N/O Donor Modes for Am(III)/Eu(III) Separation: A Theoretical Perspective.

Excellent "CHON" compatible ligands based on a heterocyclic skeleton for the separation of trivalent actinides [An(III)] from lanthanides [Ln(III)] have been widely explored, the aim being spent nuclear fuel reprocessing. The combination mode of a soft/hard (N/O) donor upon the coordination chemistry of An(III) and Ln(III) should play a vital role with respect to the performance of ligands. As such, in this work, two typical experimentally available phenanthroline-derived tetradentate ligands, CyMe4-BTPhen (L1) and Et-Tol-DAPhen (L4), and two theoretically designed asymmetric tetradentate heterocyclic ligands, L2 and L3, with various N/O donors were investigated using scalar relativistic density functional theory. We have evaluated the electronic structures of L1-L4 and their coordination modes, bonding properties, and extraction reactions with Am(III) and Eu(III). We found that the Am/Eu-N interactions play a more important role in the orbital interactions between the ligand and Am(III)/Eu(III) ions. Compared with those of L1, the coordinated O atoms of L2 and L4 weaken the metal-N bonds. The Am(III)/Eu(III) selectivity follows the order L1 > L2 > L4 based on the change in Gibbs free energy, reflecting the fact that the Am(III)/Eu(III) selectivity of the ligand is affected by the number of coordinated N atoms. In addition, L3 displays the strongest binding ability for Am(III)/Eu(III) ions and the smallest Am(III)/Eu(III) selectivity among the four ligands, due to its structural preorganization. This work clarifies the influence of the number of coordinated N and O atoms of ligands on Am(III)/Eu(III) selectivity, which provides valuable fundamental information for the design of efficient ligands with N and O donors for An(III)/Ln(III) separation.

Phytochemical Constituents from the Seeds of Capsella bursa-pastoris and Their Antioxidant Activities.

Phytochemical investigation of 70% EtOH extract of the seeds of Capsella bursa-pastoris led to the isolation of a new cyclobutane organic acid (1), and fourteen known compounds, including two organosulfur compounds (2, 3), two quinonoids (4, 5), five flavonoids (6-10), three sterols (11-13) and two other types (14, 15). The structures of the compounds were elucidated by extensive spectroscopic analyses as well as comparison of their spectroscopic data with those reported in the literature. The antioxidant capacities of all compounds and extractive fractions were evaluated by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging test and ferric reducing antioxidant power (FRAP) assay. Then the antioxidative substances were evaluated for their neuroprotective effects against H2O2-induced HT22 cell injury. The results indicated the strong scavenging ability to free radical of the extractive fractions and compounds 1-3, 8-10 and 13, and the ferric reducing antioxidant power of the extractive fractions and compounds 1-3, 8 and 10, which were close to or higher than that of the positive control trolox. The EtOAc fraction, n-BuOH fraction, and compounds 1, 3 and 8 can protect HT-22 cells from oxidative damage.

Unveiling the Reduction Mechanism of Pu(IV) by Acetaldoxime.

The separation of plutonium (Pu) from spent nuclear fuel was achieved by effectively adjusting the oxidation state of Pu from +IV to +III in the plutonium uranium reduction extraction (PUREX) process. Acetaldoxime (CH3CHNOH) as a free salt reductant can rapidly reduce Pu(IV), but the reduction mechanism remains indistinct. Herein, we explore the reduction mechanism of two Pu(IV) ions by one CH3CHNOH molecule, where the second Pu(IV) reduction is the rate-determining step with the energy barrier of 19.24 kcal mol-1, which is in line with the experimental activation energy (20.95 ± 2.34 kcal mol-1). Additionally, the results of structure and spin density analyses demonstrate that the first and second Pu(IV) reduction is attributed to hydrogen atom transfer and hydroxyl ligand transfer, respectively. Analysis of localized molecular orbitals unveils that the reduction process is accompanied by the breaking of the Pu-OOH bond and the formation of the OOH-H and C-OOH bonds. The reaction energies confirm that the reduction of Pu(IV) by acetaldoxime is both thermodynamically and kinetically accessible. In this work, we elucidate the reduction mechanism of Pu(IV) with CH3CHNOH, which provides a theoretical understanding of the rapid reduction of Pu(IV).

Efficacy and safety of microwave ablation for the treatment of multifocal versus unifocal T1N0M0 papillary thyroid carcinoma: a propensity-matched multicentre retrospective study.

OBJECTIVES: Microwave ablation (MWA) has been widely used for unifocal papillary thyroid carcinoma (U-PTC) and has recently been preliminarily used in multifocal papillary thyroid carcinoma (M-PTC). However, the efficacy and safety of MWA for M-PTC have not been investigated in large samples. The aim of the present study was to evaluate the efficacy and safety of MWA for M-PTC and compare them with MWA for U-PTC. MATERIALS AND METHODS: This retrospective multicentre study enrolled 504 patients (376 females) who underwent MWA for U-PTC (340 cases) or M-PTC (164 cases) from Jan 2015 to Dec 2020. The median age of the patients was 43 years (age range, 20-80 years). Propensity score matching (PSM) was used to balance the baseline characteristics between M-PTC group and U-PTC group. The tumour progression, tumour disappearance, and complication rates were compared between the two groups. RESULTS: The complete ablation was achieved in all enrolled cases in one session. According to the statistical results, no significant differences were shown in tumour progression-free survival (p  = 0.29) or cumulative tumour progression rate (6.7% vs. 4.3%, p  = 0.33) between the M-PTC and U-PTC groups during the follow-up time. However, the tumour disappearance rate in the M-PTC group was lower in the U-PTC group (40.9% vs. 62.8%, p < 0.001), and tumour disappearance was slower in the M-PTC group (p < 0.001). The complication rate showed no significant difference (3.0% vs. 4.9%, p  = 0.571). CONCLUSIONS: MWA is an effective and safe treatment for selected patients with M-PTC, and the prognosis is similar to that of U-PTC. CLINICAL RELEVANCE STATEMENT: The present study provided evidence that compared with unifocal papillary thyroid cancer, microwave ablation could also treat multifocal T1N0M0 papillary thyroid cancer safely with similar clinical outcome, which could promote the application of minimally invasive treatment for papillary thyroid cancer. KEY RESULTS: • Microwave ablation for multifocal and unifocal T1N0M0 papillary thyroid carcinoma had similar tumour progression rates after propensity score matching (6.7% vs. 4.3%, p = 0.33). • The tumour disappearance rate in the multifocal group was lower than that in the unifocal group (40.9% vs. 62.8%, p < 0.001), and tumour disappearance was slower in the multifocal group (p < 0.001). • Tumour size, number, and location were not risk factors for tumour progression in the multifocal papillary thyroid cancer group.

Multimodality US versus Thyroid Imaging Reporting and Data System Criteria in Recommending Fine-Needle Aspiration of Thyroid Nodules.

Background Current guidelines recommend the use of conventional US for risk stratification and management of thyroid nodules. However, fine-needle aspiration (FNA) is often recommended in benign nodules. Purpose To compare the diagnostic performance of multimodality US (including conventional US, strain elastography, and contrast-enhanced US [CEUS]) with the American College of Radiology Thyroid Imaging Reporting and Data System (TI-RADS) in the recommendation of FNA for thyroid nodules to reduce unnecessary biopsies. Materials and Methods In this prospective study, 445 consecutive participants with thyroid nodules from nine tertiary referral hospitals were recruited between October 2020 and May 2021. With univariable and multivariable logistic regression, the prediction models incorporating sonographic features, evaluated with interobserver agreement, were constructed and internally validated with bootstrap resampling technique. In addition, discrimination, calibration, and decision curve analysis were performed. Results A total of 434 thyroid nodules confirmed at pathologic analysis (259 malignant thyroid nodules) in 434 participants (mean age, 45 years ± 12 [SD]; 307 female participants) were included. Four multivariable models incorporated participant age, nodule features at US (proportion of cystic components, echogenicity, margin, shape, punctate echogenic foci), elastography features (stiffness), and CEUS features (blood volume). In recommending FNA in thyroid nodules, the highest area under the receiver operating characteristic curve (AUC) was 0.85 (95% CI: 0.81, 0.89) for the multimodality US model, and the lowest AUC was 0.63 (95% CI: 0.59, 0.68) for TI-RADS (P < .001). At the 50% risk threshold, 31% (95% CI: 26, 38) of FNA procedures could be avoided with multimodality US compared with 15% (95% CI: 12, 19) with TI-RADS (P < .001). Conclusion Multimodality US had better performance in recommending FNA to avoid unnecessary biopsies than the TI-RADS. Clinical trial registration no. NCT04574258 © RSNA, 2023 Supplemental material is available for this article.

Safety and efficacy of microwave ablation for the treatment of low-risk papillary thyroid microcarcinoma: a prospective multicenter study.

OBJECTIVES: To assess the safety and efficacy of ultrasound-guided thermal ablation for low-risk papillary thyroid microcarcinoma (PTMC) via a prospective multicenter study. METHODS: From January 2017 through June 2021, low-risk PTMC patients were screened. The management details of active surveillance (AS), surgery, and thermal ablation were discussed. Among patients who accepted thermal ablation, microwave ablation (MWA) was performed. The main outcome was disease-free survival (DFS). The secondary outcomes were tumor size and volume changes, local tumor progression (LTP), lymph node metastasis (LNM), and complication rate. RESULTS: A total of 1278 patients were included in the study. The operation time of ablation was 30.21 ± 5.14 min with local anesthesia. The mean follow-up time was 34.57 ± 28.98 months. Six patients exhibited LTP at 36 months, of whom 5 patients underwent a second ablation, and 1 patient received surgery. The central LNM rate was 0.39% at 6 months, 0.63% at 12 months, and 0.78% at 36 months. Of the 10 patients with central LNM at 36 months, 5 patients chose ablation, 3 patients chose surgery and the other 2 patients chose AS. The overall complication rate was 1.41%, and 1.10% of patients developed hoarseness of the voice. All of the patients recovered within 6 months. CONCLUSIONS: Thermal ablation of low-risk PTMC was observed to be safe and efficacious with few minor complications. This technique may help to bridge the gap between surgery and AS as treatment options for patients wishing to have their PTMC managed in a minimally invasive manner. CLINICAL RELEVANCE STATEMENT: This study proved that microwave ablation is a safe and effective treatment method for papillary thyroid microcarcinoma. KEY POINTS: Percutaneous US-guided microwave ablation of papillary thyroid microcarcinoma is a very minimally invasive treatment under local anesthesia during a short time period. The local tumor progression and complication rate of microwave ablation in the treatment of papillary thyroid microcarcinoma are very low.

Theoretical Insights on the Complexation of Americium(III) and Europium(III) with Diglycolamide- and Dimethylacetamide-Functionalized Calix[4]arenes.

Separation of minor actinides from lanthanides is one of the biggest challenges in spent fuel reprocessing due to the similar physicochemical properties of trivalent lanthanides (Ln(III)) and actinides (An(III)). Therefore, developing ligands with excellent extraction and separation performance is essential at present. As an excellent pre-organization platform, calixarene has received more attention on Ln(III)/An(III) separation. In this work, we systematically explored the complexation behaviors of the diglycolamide (DGA)/dimethylacetamide (DMA)-functionalized calix[4]arene extractants for Eu(III) and Am(III) using relativistic density functional theory (DFT). These calix[4]arene-derived ligands were obtained by functionalization with two or four binding units at the narrow edge of the calix[4]arene platform. All bonding nature analyses suggested that the Eu-L complexes possess stronger interaction compared to Am-L analogues, resulting in the higher extraction capacity of the these calix[4]arene ligands toward Eu(III). Thermodynamic analysis demonstrates that these pre-organized ligands on the calix[4]arene platform with four binding units yield better extraction abilities than the single ligands. Although DMA-functionalized ligands show stronger complexation stability for metal ions, in acidic solutions, the calix[4]arene ligands with DGA binding units have better extraction performance for Eu(III) and Am(III) due to the basicity of the DMA ligand. This work enabled us to gain a deeper understanding of the bonding properties between supramolecular ligands and lanthanides/actinides and afford useful insights into designing efficient supramolecular ligands for separating Ln(III)/An(III).

Insights into the Reduction Mechanisms of Np(VI) to Np(V) by Carbohydrazide.

An efficient approach to Np separation in the Plutonium Uranium Reduction EXtraction (PUREX) process is to adjust Np(VI) to Np(V) by free-salt reductants, such as hydrazine and its derivatives. Recently, carbohydrazide (CO(N2H3)2), a derivative of hydrazine and urea, has received much attention, which can reduce Np(VI) to Np(V) in the extraction reprocessing of spent nuclear fuel. Herein, according to the experimental observations, we examine the reduction mechanism of four Np(VI) by one carbohydrazide molecule using multiple theoretical calculations. The fourth Np(VI) reduction with a 22.26 kcal mol-1 energy barrier is the rate-determining step, which is in accordance with the experimental observations (20.54 ± 1.20 kcal mol-1). The results of spin density reflect that the reduction of the first and third Np(VI) ion is an outer-sphere electron transfer, while that of the second and fourth Np(VI) ion is the hydrogen transfer. Localized molecular orbitals (LMOs) uncover that the breaking of the N-H bond and formation of the Oyl-H bond are accompanied by the reaction from initial complexes (ICs) to intermediates (INTs). This work offers basic perspectives for the reduction mechanism of Np(VI) to Np(V) by CO(N2H3)2, which is also expected to design excellent free-salt Np(VI) reductants for the separation of Np in the advanced PUREX process.

Theoretical Insights into the Selectivity of Hydrophilic Sulfonated and Phosphorylated Ligands to Am(III) and Eu(III) Ions.

The separation of lanthanides and actinides has attracted great attention in spent nuclear fuel reprocessing up to date. In addition, liquid-liquid extraction is a feasible and useful way to separate An(III) from Ln(III) based on their relative solubilities in two different immiscible liquids. The hydrophilic bipyridine- and phenanthroline-based nitrogen-chelating ligands show excellent performance in separation of Am(III) and Eu(III) as reported previously. To profoundly explore the separation mechanism, herein, we first of all designed four hydrophilic sulfonated and phosphorylated ligands L1, L2, L3, and L4 based on the bipyridine and phenanthroline backbones. In addition, we studied the structures of these ligands and their neutral complexes [ML(NO3)3] (M = Am, Eu) as well as the thermodynamic properties of complexing reactions through the scalar relativistic density functional theory. According to the changes of the Gibbs free energy for the back-extraction reactions, the phenanthroline-based ligands L2 and L4 have stronger complexing capacity for both Am(III) and Eu(III) ions while the phosphorylated ligand L3 with the bipyridine framework has the highest Am(III)/Eu(III) selectivity. In addition, the charge decomposition analysis revealed a higher degree of charge transfer from the ligand to Am(III), suggesting stronger donor-acceptor interactions in the Am(III) complexes. This study can provide theoretical insights into the separation of actinide(III)/lanthanide(III) using hydrophilic sulfonated and phosphorylated N-donor ligands.

Microwave Ablation for Papillary Thyroid Microcarcinoma with and without US-detected Capsule Invasion: A Multicenter Prospective Cohort Study.

Background Microwave ablation (MWA) has achieved favorable results in the treatment of papillary thyroid microcarcinoma (PTMC) confined in glandular parenchyma. However, studies on the outcome of MWA for PTMC with US-detected capsular invasion remain unclarified in the literature. Purpose To compare the feasibility, effectiveness, and safety of MWA in the treatment of PTMC with and without US-detected capsular invasion. Materials and Methods Participants from 12 hospitals with a PTMC maximal diameter of 1 cm or less without US- or CT-detected lymph node metastasis (LNM) who planned to undergo MWA were enrolled in this prospective study between December 2019 and April 2021. All tumors were evaluated with preoperative US and were divided into those with and those without capsular invasion. The participants were observed until July 1, 2022. The primary end points, including technical success and disease progression, and the secondary end points, including treatment parameters, complications, and tumor shrinkage during follow-up, were compared between the two groups, and multivariable regression was performed. Results After exclusion, 461 participants (mean age, 43 years ± 11 [SD]; 337 women) were included: 83 with and 378 without capsular invasion. After one participant with capsular invasion aborted MWA because of technical failure, 82 participants with and 378 participants without capsular invasion (mean tumor volume, 0.1 mL ± 0.1 vs 0.1 mL ± 0.1; P = .07) were analyzed with a mean follow-up period of 20 months ± 4 (range, 12-25 months) and 21 months ± 4 (range, 11-26 months), respectively. In those with and those without capsular invasion, comparable technical success rates were achieved (99% [82 of 83] vs 100% [378 of 378], P = .18), with one and 11 complications, respectively (1% [one of 82] vs 3% [11 of 378], P = .38). There was no evidence of differences in disease progression (2% [one of 82] vs 1% [four of 378]; P = .82) or tumor shrinkage (mean, 97% ± 8 [SD] vs 96% ± 13; P = .58). Conclusion Microwave ablation was feasible in the treatment of papillary thyroid microcarcinoma with US-detected capsular invasion and showed comparable short-term efficacy with or without the presence of capsular invasion. © RSNA, 2023 Clinical trial registration no. NCT04197960 Supplemental material is available for this article.

Theoretical Insights into the Substitution Effect of Phenanthroline Derivatives on Am(III)/Eu(III) Separation.

Separation of trivalent actinides (An(III)) and lanthanides (Ln(III)) poses a huge challenge in the reprocessing of spent nuclear fuel due to their similar chemical properties. N,N'-Diethyl-N,N'-ditolyl-2,9-diamide-1,10-phenanthroline (Et-Tol-DAPhen) is a potential ligand for the extraction of An(III) from Ln(III), while there are still few reports on the effect of its substituent including electron-withdrawing and electron-donating groups on An(III)/Ln(III) separation. Herein, the interaction of Et-Tol-DAPhen ligands modified by the electron-withdrawing groups (CF3, Br) and electron-donating groups (OH) with Am(III)/Eu(III) ions was investigated using scalar relativistic density functional theory (DFT). The analyses of bond order, quantum theory of atoms in molecules (QTAIM), and molecular orbital (MO) indicate that the substitution groups have a slight effect on the electronic structures of the [M(L-X)(NO3)3] (X = CF3, Br, OH) complexes. However, the thermodynamic results suggest that a ligand with the electron-donating group (L-OH) improves the extraction ability of metal ions, and the ligand modified by the electron-withdrawing group (L-Br) has the best Am(III)/Eu(III) selectivity. This work could render new insights into understanding the effect of electron-withdrawing and electron-donating groups in tuning the selectivity of Et-Tol-DAPhen derivatives and pave the way for designing new ligands modified by substituted groups with better extraction ability and An(III)/Ln(III) selectivity.

Experimental and theoretical studies on the extraction behavior of Cf(iii) by NTAamide(C8) ligand and the separation of Cf(iii)/Cm(iii).

In this work we studied the extraction behaviors of Cf(iii) by NTAamide (N,N,N',N',N'',N''-hexaocactyl-nitrilotriacetamide, C8) in nitric acid medium. Influencing factors such as contact time, concentration of NTAamide(C8), HNO3 and NO3 - as well as temperature were considered. The slope analysis showed that Cf(iii) should be coordinated in the form of neutral molecules, and the extraction complex should be Cf(NO3)3·2L (L = NTAamide(C8)), which can achieve better extraction effect under the low acidity condition. When the concentration of HNO3 was 0.1 mol L-1, the separation factor (SFCf/Cm) was 3.34. The extractant has application prospect to differentiate the trivalent Cf(iii) and Cm(iii) when the concentration of nitric acid is low. On the other hand, density functional theory (DFT) calculations were conducted to explore the coordination mechanism of NTAamide(C8) ligands with Cf/Cm cations. The NTAamide(C8) complexes of Cf(iii)/Cm(iii) have similar geometric structures, and An(iii) is more likely to form a complex with 1 : 2 stoichiometry (metal ion/ligands). In addition, bonding property and thermodynamics analyses showed that NTAamide(C8) ligands had stronger coordination ability with Cf(iii) over Cm(iii). Our work provides meaningful information with regard to the in-group separation of An(iii) in practical systems.

Microwave ablation vs. surgery for papillary thyroid carcinoma with minimal sonographic extrathyroid extension: a multicentre prospective study.

OBJECTIVES: Minimal extrathyroid extension (mETE) was removed from the TNM staging system. This study was designed prospectively to compare the safety and efficacy of microwave ablation (MWA) versus surgery for treating T1N0M0 papillary thyroid carcinomas (PTC) with sonographically detected mETE. METHODS: From December 2019 to April 2021, 198 patients with T1N0M0 mETE-PTCs evaluated by preoperative ultrasound from 10 hospitals were included. Ninety-two patients elected MWA, and 106 patients elected surgery for treatment. MWA was performed using extensive ablation with hydrodissection. Surgery consisted of lobectomy with ipsilateral central lymph node dissection (CLD), lobe and isthmus excision with ipsilateral CLD and total thyroidectomy with ipsilateral CLD. The rates of technical success, cost, oncologic outcomes, complications and quality of life of the two groups were assessed. RESULTS: The follow-up times for the MWA and surgery groups were 12.7 ± 4.1 and 12.6 ± 5.0 months, respectively. The technical success rate was 100% for both groups. Oncological outcomes of the two groups were similar during the follow-up (all p > 0.05). The MWA group had a shorter operation time, less blood loss and lower costs (all p < 0.001). Three complications (3.3%) were reported in the MWA group and 4 (3.8%) in the surgery group (p = 0.846). The surgery group had higher scores for scar problems and anxiety (p < 0.001 and p = 0.003, respectively). CONCLUSIONS: Microwave ablation was comparable in the short term to surgery in terms of treatment safety and efficacy in selected patients with T1N0M0 mETE-PTC detected by ultrasound. KEY POINTS: • Microwave ablation is comparable to surgery in the safety and short-term efficacy for PTCs with sonographically detected mETE. • Thermal ablation is technically feasible for mETE-PTC treatment. • Patients with mETE-PTC have similar quality of life in the two groups, except for worse scar problems and anxiety in the surgery group.

Actinide-doped boron clusters: from borophenes to borospherenes.

Similar to graphene and fullerene, metal-doping has been considered to be an effective approach to the construction of highly stable boron clusters. In this work, a series of actinide metal-doped boron clusters AnB36 (An = Pa, Np, Pu, Am, Cm, Bk, and Cf) have been explored using extensive first-principles calculations. We found that the quasi-planar structure of B36 transforms to an endohedral borospherene An@B36 after actinide metal doping. Actinoborospherenes exhibit C2h symmetry with Pa, Np, and Pu dopants and for Am, Cm, Bk and Cf dopants with larger atomic radii, the symmetry of An@B36 is reduced to Ci. Bonding property analyses such as bond order, molecular orbital (MO) and quantum theory of atoms in molecules (QTAIM) analysis show that the covalency of the An-B bonds in C2h An@B36 (An = Pa, Np, and Pu) is higher than that in Ci An@B36 (An = Am, Cm, Bk, and Cf). These endohedral borospherenes are robust according to thermodynamic and dynamic analyses. As expected, the Ci An@B36 clusters are less stable compared to C2h An@B36, which is consistent with the stronger covalent bonds of the latter. These results indicate that the existence of the actinide-boron bonding is essential for the high stability of the An@B36 clusters, confirming that the fullerene-like boron cages can be stabilized by actinide encapsulation. This work is expected to provide potential routes for the construction of robust borospherenes.

Global airborne bacterial community-interactions with Earth's microbiomes and anthropogenic activities.

Airborne bacteria are an influential component of the Earth's microbiomes, but their community structure and biogeographic distribution patterns have yet to be understood. We analyzed the bacterial communities of 370 air particulate samples collected from 63 sites around the world and constructed an airborne bacterial reference catalog with more than 27 million nonredundant 16S ribosomal RNA (rRNA) gene sequences. We present their biogeographic pattern and decipher the interlacing of the microbiome co-occurrence network with surface environments of the Earth. While the total abundance of global airborne bacteria in the troposphere (1.72 × 1024 cells) is 1 to 3 orders of magnitude lower than that of other habitats, the number of bacterial taxa (i.e., richness) in the atmosphere (4.71 × 108 to 3.08 × 109) is comparable to that in the hydrosphere, and its maximum occurs in midlatitude regions, as is also observed in other ecosystems. The airborne bacterial community harbors a unique set of dominant taxa (24 species); however, its structure appears to be more easily perturbed, due to the more prominent role of stochastic processes in shaping community assembly. This is corroborated by the major contribution of surface microbiomes to airborne bacteria (averaging 46.3%), while atmospheric conditions such as meteorological factors and air quality also play a role. Particularly in urban areas, human impacts weaken the relative importance of plant sources of airborne bacteria and elevate the occurrence of potential pathogens from anthropogenic sources. These findings serve as a key reference for predicting planetary microbiome responses and the health impacts of inhalable microbiomes with future changes in the environment.

Theoretical insights into the separation of Am(III)/Eu(III): designing ligands based on a preorganization strategy.

Separation of trivalent actinide (An(III)) and lanthanide (Ln(III)) is a worldwide challenge of nuclear waste treatment. Designing ligands with efficient An(III)/Ln(III) separation performance is still one of the key issues for the disposal of accumulated radioactive waste and the recovery of minor actinides. Recently, N-heterocyclic ligands modified with amide groups have shown excellent An(III)/Ln(III) separation performance. The preorganized structure of the ligands has a great impact on the An(III)/Ln(III) separation performance. We theoretically investigated the extraction behaviors of Am(III) and Eu(III) using phenanthroline (L1 and L2) and bipyridine (L3 and L4) based ligands with a completely or partially preorganized structure. The properties of these ligands and their coordination structures, bonding nature and thermodynamic behaviors with the Am(III) and Eu(III) complexes have been systematically studied in a theoretical fashion. The analyses of the bonding nature suggest that the Am-N bonds possess more covalence than the Eu-N bonds. The thermodynamic results indicate that L2 with a completely preorganized structure has the strongest extraction ability and the best Am(III)/Eu(III) selectivity, while L3 with the most flexible skeleton appears to have the weakest extraction ability and the lowest Am(III)/Eu(III) selectivity. And L1 and L4 have similar performances with regard to Am(III)/Eu(III) selectivity. The results suggest that a certain degree of preorganization of the ligand structure can enhance the extraction ability and Am(III)/Eu(III) selectivity. This work provides valuable information for designing efficient ligands for An(III)/Ln(III) separation by the preorganization strategy.

Theoretical Insights into Phenanthroline-Based Ligands toward the Separation of Am(III)/Eu(III).

The bistriazinyl-phenanthroline representative ligand, BTPhen, shows excellent extraction and separation ability for trivalent actinides and lanthanides. Herein, we first designed three phenanthroline-based nitrogen-donor ligands (L1, L2, and L3), and then studied the structural and bonding properties as well as thermodynamic properties of the probable complexes, ML(NO3)3 (M = Am or Eu and L = L1, L2, or L3), using scalar relativistic density functional theory. Our charge decomposition analysis revealed an obviously higher charge transfer from the ligand to Am(III) compared with the Eu(III) case for the studied complexes. Spin density analysis further showed a more significant degree of Am-to-ligand spin delocalization and the corresponding spin polarization on the ligands. According to the thermodynamic analysis, ligand L3 has the strongest complexation capacity for both Am(III) and Eu(III) ions, while ligand L1 has the highest Am(III)/Eu(III) selectivity in binary octanol/water solutions. We expected that this work can provide valuable theoretical support for the design of effective ligands for actinide(III)/lanthanide(III) separation in high level liquid waste.