ABSTRACT
Background: Few clinical data are available on thulium fiber laser (TFL) and conservative treatment of upper urinary tract urothelial carcinoma (UTUC). Objective: To assess the effectiveness and safety of TFL in the conservative treatment of UTUC in terms of both tumor ablation and complication rates in a short-term follow-up. Design setting and participants: Retrospective data were collected from all patients who underwent endoscopic management of UTUC between January 2021 and April 2022. All patients with nonmetastatic UTUC who were deemed suitable candidates (low- and high-grade disease) for conservative treatment were reviewed. Intervention: All patients underwent ureteroscopy with biopsy and at 2, 6, and 12 mo after the first surgery. UTUC ablation was achieved using TFL. Outcome measurements and statistical analysis: Clinical data were collected in a dedicated database. Intra- and postoperative outcomes were assessed. A descriptive statistical analysis was performed. Results and limitations: In total, 28 patients were evaluated. Thirteen patients (46.4%) were included in the low-risk UTUC treatment group and 15 (53.6%) in the high-risk group. The mean tumor size was 15.3 ± 5.7 mm. Biopsy showed low- and high-grade UTUCs in 19 and eight patients, respectively. Only one biopsy was inconclusive for achieving a diagnosis. At the second procedure biopsy, no tumor was found in 19 cases (70.4%), whereas seven had tumors confirmed (25.9%). To date, 23 and 17 out of 26 patients completed the 6- and 12-mo follow-up, respectively. UTUC recurrence was detected in five of 23 patients (21.7%) and in three of 17 patients (17.7%) at 6 and 12 mo, respectively. A total of 95 procedures were performed. No intraoperative complications were observed. In ten of the 95 procedures (10.5%), Clavien-Dindo grade I-II postoperative complications were experienced. Only one grade IIIB postoperative complication was noted. Conclusions: TFL is a safe and effective technique for conservative treatment of UTUC in a short-term follow-up. Optimal tumor ablation and fine hemostatic control were achieved without major complications. Patient summary: In this study, we looked at the outcomes of upper urinary tract tumors conservatively treated with the new thulium fiber laser (TFL). We conclude that TFL represents a safe and effective technique for the treatment of this kind of tumors in a short-term follow-up.
ABSTRACT
The molecular wheel [Cr10(OMe)20(O2CCMe3)10], abbreviated {Cr10}, with an unusual intermediate total spin S = 9 and non-negligible cluster anisotropy, D/kB = -0.045(2) K, is a rare case among wheels based on an even number of 3d-metals, which usually present an antiferromagnetic (AF) ground state (S = 0). Herein, we unveil the origin of such a behavior. Angular magnetometry measurements performed on a single crystal confirmed the axial anisotropic behavior of {Cr10}. For powder samples, the temperature dependence of the susceptibility plotted as χT(T) showed an overall ferromagnetic (FM) behavior down to 1.8 K, whereas the magnetization curve M(H) did not saturate at the expected 30 µB/fu for 10 FM coupled 3/2 spin Cr3+ ions, but to a much lower value, corresponding to S = 9. In addition, the X-ray magnetic circular dichroism (XMCD) measured at high magnetic field (170 kOe) and 7.5 K showed the polarization of the cluster moment up to 23 µB/fu. The magnetic results can be rationalized within a model, including the cluster anisotropy, in which the {Cr10} wheel is formed by two semiwheels, each with four Cr3+ spins FM coupled (JFM/kB = 2.0 K), separated by two Cr3+ ions AF coupled asymmetrically (J23/kB = J78/kB = -2.0 K; J34/kB = J89/kB = -0.25 K). Inelastic neutron scattering and heat capacity allowed us to confirm this model leading to the S = 9 ground state and first excited S = 8. Single-molecule magnet behavior with an activation energy of U/kB = 4.0(5) K in the absence of applied field was observed through ac susceptibility measurements down to 0.1 K. The intriguing magnetic behavior of {Cr10} arises from the detailed asymmetry in the molecule interactions produced by small-angle distortions in the angles of the Cr-O-Cr alkoxy bridges coupling the Cr3+ ions, as demonstrated by ab initio and density functional theory calculations, while the cluster anisotropy can be correlated to the single-ion anisotropies calculated for each Cr3+ ion in the wheel.
ABSTRACT
Thermal expansion, electrical resistivity, magnetization, and specific heat measurements were performed on URu2-xFexSi2 single crystals for various values of Fe concentration x in both the hidden-order (HO) and large-moment antiferromagnetic (LMAFM) regions of the phase diagram. Our results show that the paramagnetic (PM) to HO and LMAFM phase transitions are manifested differently in the thermal expansion coefficient. The uniaxial pressure derivatives of the HO/LMAFM transition temperature T0 change dramatically when crossing from the HO to the LMAFM phase. The energy gap also changes consistently when crossing the phase boundary. In addition, for Fe concentrations at xc ≈ 0.1, we observe two features in the thermal expansion upon cooling, one that appears to be associated with the transition from the PM to the HO phase and another one at lower temperature that may be due to the transition from the HO to the LMAFM phase.
