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Objective: To assess the efficacy and outcomes of percutaneous ablative therapies for hepatocellular carcinoma (HCC) in the caudate lobe. Methods: Patients within Milan criteria, who underwent thermal ablation (RFA/MWA) for HCC were analyzed. Based on the inclusion-criteria, patients were categorized in two groups. Group-1 (caudate-lobe HCC) and Group-2 (non-caudate-lobe HCC). Both the groups were analyzed for technical success (TS), local tumor progression (LTP), disease-free survival (DFS), and overall survival (OS) were compared between both the groups. Predictive factors for LTP, DFS, or OS in the study cohort were analyzed using appropriate statistical analyses. Results: Twenty-one patients qualified to be in Group-1 while 130 patients fulfilled the criteria for Group-2. TS of 90.5 and 97.7% was seen after the first session of ablation for Group-1 and group-2 respectively, while a TS of 95.2% (Group-1) and 100% (Group-2) was achieved after second session. The right-intercostal-approach was used in 66.7% (n = 14) and the anterior-epigastric-approach was used in 33.3% (n = 7) of patients having caudate-lobe HCC. Procedure-related complications in both the groups were comparable. Although, statistically insignificant, LTP in the Group-1 (19.5%, n = 4) was twice that of non-caudate lobe HCC (8.5%, n = 11). The cumulative DFS rate was better in Group-2 while OS in both groups were comparable. Multivariate analysis showed: tumor size and ablative margin of 5 mm being independent predictors of LTP after percutaneous-ablation of caudate-lobe HCC. Conclusion: Ablative therapies for HCC in caudate lobe is feasible and safe with comparable LTP and OS to non-caudate lobe HCC. Tumor size >2 cm and lack of 5 mm ablative margin are independent predictors of LTP. Advances in knowledge: 1. Percutaneous ablation of caudate lobe HCC is feasible using anterior epigastric approach or right intercostal approach. 2. These approaches may allow a safe and effective ablation of caudate lobe HCC with results comparable to non-caudate HCC ablation.

High entropy oxides (HEOs), which contain multiple elements in the same crystallographic site, are a promising platform for electrocatalysis in oxygen evolution reaction (OER). However, to date, all OER studies involving HEOs have used it in polycrystalline bulk form. In this study, the OER activity of a set of single crystalline thin films of (La0:2Pr0:2Nd0:2Sm0:2Eu0:2)NiO3, grown on NdGaO3 substrates have been investigated. The OER activity increases with the thickness of the film. X-ray absorption spectroscopy measurements find an increase in Ni d-O p covalency and a decrease in charge transfer energy with the increase in film thickness. These facilitate higher charge transfer between Ni and surface absorbates, resulting in higher OER activity. However, the epitaxial stabilization of thicker film becomes difficult due to the requirement of +3 oxidation state of Ni and the OER activity of a 75 unit cell thick film is found to be the optimal in the present study. This work demonstrates that the thickness of perovskite oxides can be used as a parameter to enhance OER activity.

Transition metal based oxide heterostructures exhibit diverse emergent phenomena e.g. two dimensional electron gas, superconductivity, non-collinear magnetic phase, ferroelectricity, polar vortices, topological Hall effect etc., which are absent in the constituent bulk oxides. The microscopic understandings of these properties in such nanometer thick materials are extremely challenging. Synchrotron x-ray based techniques such as x-ray diffraction, x-ray absorption spectroscopy (XAS), resonant x-ray scattering (RXS), resonant inelastic x-ray scattering (RIXS), x-ray photoemission spectroscopy, etc. are essential to elucidating the response of lattice, charge, orbital, and spin degrees of freedoms to the heterostructuring. As a prototypical case of complex behavior, rare-earth nickelates (RENiO3 with RE=La, Pr, Nd, Sm, Eu, Lu) based thin films and heterostructures have been investigated quite extensively in recent years. An extensive body of literature about these systems exists and for an overview of the field, we refer the interested readers to the recent reviews Annual Review of Materials Research 46, 305 (2016) and Reports on Progress in Physics 81, 046501 (2018). In the present article, we give a brief review that concentrates on the use of synchrotron based techniques to investigate a specific set of EuNiO3/LaNiO3 superlattices, specifically designed to solve a long-standing puzzle about the origin of simultaneous electronic, magnetic and structural transitions of the RENiO3 series., Comment: Invited Review Article

The study of phase transitions is crucial to understanding the physics of materials and utilizing them for technological applications. This article presents a detailed analysis of the electronic transport properties of high entropy oxide thin films. We observe an increase in resistance fluctuations across a first-order phase transition. We show that the noise arises from an electronic phase separation accompanying the spin ordering due to the formation of domains of localized and delocalized charges. We conclude that due to charge disproportionation, the charge carriers form domains of localized and delocalized electrons in this system. Our study establishes the existence of multiple states with near equal energy in such complex oxide thin films.

Undescended testis or cryptorchidism is the most common predisposing factor in the development of testicular germ cell tumors with seminoma being the most common type. Therefore, testicular malignancy should be ruled out in case of an abdominal mass in a cryptorchid patient. Here, we present a case of intra-abdominal seminoma transformation of the undescended right testis with retroperitoneal nodal metastasis in a 54-year-old male which was clinically manifested as a gradually enlarging intra-abdominal mass and dull aching lower abdominal pain. He was managed with surgical removal, followed by chemotherapy.

The choice of electrostatic gating over the conventional chemical doping for phase engineering of quantum materials is attributed to the fact that the former can reversibly tune the carrier density without affecting the system's level of disorder. However, this proposition seems to break down in field-effect transistors involving SrTiO$_3$ (STO) based two-dimensional electron gases. Such peculiar behavior is associated with the electron trapping under an external electric field. However, the microscopic nature of trapping centers remains an open question. In this paper, we investigate electric field-induced charge trapping/detrapping phenomena at the conducting interface between band insulators $\gamma$-Al$_2$O$_3$ and STO. Our transport measurements reveal that the charge trapping under +ve back gate voltage ($V_g$) above the tetragonal to cubic structural transition temperature ($T_c$) of STO is contributed by the electric field-assisted thermal escape of electrons from the quantum well, and the clustering of oxygen vacancies (OVs) as well. We observe an additional source of trapping below the $T_c$, which arises from the trapping of free carriers at the ferroelastic twin walls of STO. Application of -ve $V_g$ results in a charge detrapping, which vanishes above $T_c$ also. This feature demonstrates the crucial role of structural domain walls in the electrical transport properties of STO based heterostructures. The number of trapped (detrapped) charges at (from) the twin wall is controlled by the net polarity of the wall and is completely reversible with the sweep of $V_g$., Comment: 5 Figures

Heterostructure engineering provides an efficient way to obtain several emergent phases of LaNiO3, as demonstrated in recent studies. In this work, a new class of short-periodic superlattice, consisting of LaNiO3 and EuNiO3, has been grown by pulsed laser interval deposition to investigate the effect of structural symmetry mismatch on the electronic and magnetic behaviors. Using synchrotron-based soft and hard x-ray resonant scattering experiments, we have found that these heterostructures undergo simultaneous electronic and magnetic transitions. Most importantly, LaNiO3 within these artificial structures exhibits a new antiferromagnetic, charge ordered insulating phase, which may be a potential candidate to achieve high temperature superconductivity.

Understanding the electronic behavior of Ni$^{2+}$ in a square planar environment of oxygen is the key to unravel the origin of the recently discovered superconductivity in the hole doped nickelate Nd$_{0.8}$Sr$_{0.2}$NiO$_2$. To identify the major similarities/dissimilarities between nickelate and cuprate superconductivity, the study of the electronic structure of Ni$^{2+}$ and Cu$^{2+}$ in an identical square planar environment is essential. In order to address these questions, we investigate the electronic structure of Sr$_2$CuO$_3$ and Ni doped Sr$_2$CuO$_3$ single crystals containing (Cu/Ni)O$_4$ square planar units. Our polarization dependent X-ray absorption spectroscopy experiments for Ni in Sr$_2$Cu$_{0.9}$Ni$_{0.1}$O$_3$ have revealed very large orbital polarization, which is a characteristic feature of high $T_c$ cuprate. This arises due to the low spin $S$=0 configuration with two holes in Ni 3$d_{x^2-y^2}$ orbitals - in contrast to the expected high spin $S$=1 state from Hund's first rule. The presence of such $S$=0 Ni$^{2+}$ in hole doped nickelate would be analogous to the Zhang Rice singlet. However, the Mott Hubbard insulating nature of the NiO$_4$ unit would point towards a different electronic phase space of nickelates, compared to high $T_c$ cuprates., Comment: 4 Figures

The discovery of skyrmions has sparked tremendous interests about topologically nontrivial spin textures in recent times. The signature of noncoplanar nature of magnetic moments can be observed as topological Hall effect (THE) in electrical measurement. Realization of such nontrivial spin textures in new materials and through new routes is an ongoing endeavour due to their huge potential for future ultra-dense low-power memory applications. In this work, we report oxygen vacancy (OV) induced THE and anomalous Hall effect (AHE) in a 5$d^0$ system KTaO$_3$. The observation of weak antilocalization behavior and THE in the same temperature range strongly implies the crucial role of spin-orbit coupling (SOC) behind the origin of THE. Ab initio calculations reveal the formation of the magnetic moment on Ta atoms around the OV and Rashba-type spin texturing of conduction electrons. In the presence of Rashba SOC, the local moments around vacancy can form bound magnetic polarons (BMP) with noncollinear spin texture, resulting THE. Scaling analysis between transverse and longitudinal resistance establishes skew scattering driven AHE in present case. Our study opens a route to realize topological phenomena through defect engineering., Comment: Published in Advanced Quantum Technology

High entropy oxides (HEOs) are a class of materials, containing equimolar portions of five or more transition metal and/or rare-earth elements. We report here about the layer-by-layer growth of HEO [(La$_{0.2}$Pr$_{0.2}$Nd$_{0.2}$Sm$_{0.2}$Eu$_{0.2}$)NiO$_3$] thin films on NdGaO$_3$ substrates by pulsed laser deposition. The combined characterizations with in-situ reflection high energy electron diffraction, atomic force microscopy, and X-ray diffraction affirm the single crystalline nature of the film with smooth surface morphology. The desired +3 oxidation of Ni has been confirmed by an element sensitive X-ray absorption spectroscopy measurement. Temperature dependent electrical transport measurements revealed a first order metal-insulator transition with the transition temperature very similar to the undoped NdNiO$_3$. Since both of these systems have a comparable tolerance factor, this work demonstrates that the electronic behaviors of $A$-site disordered perovskite-HEOs are primarily controlled by the average tolerance factor., Comment: 4 figures

Doubly fed induction generator (DFIG) has superior performance, lower cost, control flexibility and lower cost. That makes it favorable variable speed generator for wind energy application. This paper presents a Direct Torque Control (DTC) method for DFIG. In this research rotor side voltage and current signal are employed to estimate electromagnetic torque, rotor flux and its position, which are further used to generate appropriate rotor voltage vector by Rotor Side Converter (RSC). Consequently magnitude and angle of rotor voltage are utilized to maneuver electromagnetic torque which in turn control the power generated from the stator as it is varies proportional to the torque at constant speed.

We report on the electronic and magnetic properties of a series of [m EuNiO3/p LaNiO3] superlattices (thickness m and/or p = 1 unit cell) epitaxially grown on single crystalline NdGaO3 substrates. The structural symmetry of these films has been investigated by the combination of in-situ reflection high energy electron diffraction and X-ray diffraction measurements. The metal-insulator transition and the magnetic transition temperatures of the short-period superlattices with m ≥ p are modified from the corresponding bulk Eu1–xLaxNiO3 (x=pm+p) composition. In contrast to the corresponding bulk doped compound with x = 0.67, the [1 EuNiO3/2 LaNiO3] film remains metallic down to at least 2 K without signs of electronic or magnetic transitions. These findings demonstrate the power of the digital synthesis approach to realize electronic and magnetic phases of perovskite nickelates, unattainable in bulk.