Chiral magnetoresistance in Pt/Co/Pt zigzag wires

The Rashba effect leads to a chiral precession of the spins of moving electrons while the Dzyaloshinskii-Moriya interaction (DMI) generates preference towards a chiral profile of local spins. We predict that the exchange interaction between these two spin systems results in a 'chiral' magnetoresistance depending on the chirality of the local spin texture. We observe this magnetoresistance by measuring the domain wall (DW) resistance in a uniquely designed Pt/Co/Pt zigzag wire, and by changing the chirality of the DW with applying an in-plane magnetic field. A chirality-dependent DW resistance is found, and a quantitative analysis shows a good agreement with a theory based on the Rashba model. Moreover, the DW resistance measurement allows us to independently determine the strength of the Rashba effect and the DMI simultaneously, and the result implies a possible correlation between the Rashba effect, the DMI, and the symmetric Heisenberg exchange

Enhanced magnetic and thermoelectric properties in epitaxial polycrystalline SrRuO3 thin film

Transition metal oxide thin films show versatile electrical, magnetic, and thermal properties which can be tailored by deliberately introducing macroscopic grain boundaries via polycrystalline solids. In this study, we focus on the modification of the magnetic and thermal transport properties by fabricating single- and polycrystalline epitaxial SrRuO3 thin films using pulsed laser epitaxy. Using epitaxial stabilization technique with atomically flat polycrystalline SrTiO3 substrate, epitaxial polycrystalline SrRuO3 thin film with crystalline quality of each grain comparable to that of single-crystalline counterpart is realized. In particular, alleviated compressive strain near the grain boundaries due to coalescence is evidenced structurally, which induced enhancement of ferromagnetic ordering of the polycrystalline epitaxial thin film. The structural variations associated with the grain boundaries further reduce the thermal conductivity without deteriorating the electronic transport, and lead to enhanced thermoelectric efficiency in the epitaxial polycrystalline thin films, compared with their single-crystalline counterpart.Comment: 24 pages, 5 figure

Decreased DBC1 Expression Is Associated With Poor Prognosis in Patients With Non-Muscle-Invasive Bladder Cancer

Purpose The deleted in bladder cancer 1 (DBC1) gene is located within chromosome 9 (9q32-33), a chromosomal region that frequently shows loss of heterozygosity in bladder cancer (BC). It is suspected that it acts as a tumor suppressor gene, but its prognostic value remains unclear. The aim of the present study was to investigate the value of DBC1 as a prognostic marker in BC. Materials and Methods The expression of DBC1 was determined by real-time polymerase chain reaction analysis in 344 patients with BC (220 non-muscle-invasive BC [NMIBC] and 124 muscle-invasive BC [MIBC]) and in 34 patients with normal bladder mucosa. The results were compared with clinicopathologic parameters, and the prognostic value of DBC1 was evaluated by Kaplan-Meier analysis and a multivariate Cox regression model. Results: DBC1 expression was significantly decreased in patients with MIBC compared with those diagnosed with NMIBC (p=0.010). Patients with aggressive tumor characteristics had lower DBC1 expression levels in NMIBC (each, p<0.05). By multivariate Cox regression analysis, low DBC1 expression was a predictor of progression to MIBC (hazard ratio, 7.104; p=0.013). Kaplan-Meier estimates revealed a significant difference in tumor recurrence, progression to MIBC, and cancer-specific survival depending on the level of DBC1 expression in NMIBC (log-rank test, each, p<0.05). Conclusions: The expression of DBC1 was associated with tumor aggressiveness, progression to MIBC, and survival in NMIBC. Our results suggest that DBC1 expression can be a useful prognostic marker for patients with NMIBC

VIRTUAL STAIN CONVERSION BETWEEN IMMUNOHISTOCHEMISTRY AND HEMATOXYLIN & EOSIN IMAGES USING DEEP GENERATIVE MODELS FOR INFERENCE OF PANCREATIC ISLET CELLULAR COMPOSITION IN TYPE 1 DIABETES

In Type 1 diabetes (T1D) patients, insulin-producing β-cells residing in the islets of Langerhans are selectively destroyed due to autoimmunity. This is mostly due to the complex interplay between the islets of Langerhans and nearby structures of the pancreas, which is yet to be deciphered. An effective and long-lasting therapeutic for globally increasing T1D patients has not been developed yet due to the knowledge voids in the pathophysiology of T1D. Specifically, researchers have been struggling to determine if β-cell destruction is caused by the immune system or is self-inflicted. In order to analyze this, pancreatic tissue blocks were sectioned to slides and stained with immunohistochemistry (IHC) and hematoxylin & eosin (H&E) stains to identify the spatial correlation between the islets and the nearby structures. However, IHC and H&E stains cannot be stained concurrently on the same slide of the tissue block, leading to the classic intra-slide variation problem. Therefore, this study utilized several deep generative models, including a new class of conditional diffusion models called Image-to-Image Schrödinger Bridge (I2SB), to virtually stain between IHC and H&E slides of the tissue block. Since most, if not all, of the previous virtual staining works utilized Generative Adversarial Networks (GANs), GANs and I2SB models were trained and evaluated in their ability to generate a virtual H&E image of high perceptual quality. By utilizing segmentation model-based and model-free evaluation methods, it was shown that a “conditional” variant of I2SB model, I2SB-cond, performed the best in the generation of virtual H&E images, but was not utilized due to its conditioned tissue map suffering from the intra-slide variation problem. The state-of-the-art GAN model for virtual staining and the vanilla I2SB model performed similarly, and was utilized to generate virtual WSIs, showing that these models can indeed be utilized to resolve the intra-slide variation problem. Lastly, the dominant performance of I2SB-cond model hints at its future potential for virtually staining the islets, or generation of virtual IHC images

VIRTUAL STAIN CONVERSION BETWEEN IMMUNOHISTOCHEMISTRY AND HEMATOXYLIN & EOSIN IMAGES USING DEEP GENERATIVE MODELS FOR INFERENCE OF PANCREATIC ISLET CELLULAR COMPOSITION IN TYPE 1 DIABETES

In Type 1 diabetes (T1D) patients, insulin-producing β-cells residing in the islets of Langerhans are selectively destroyed due to autoimmunity. This is mostly due to the complex interplay between the islets of Langerhans and nearby structures of the pancreas, which is yet to be deciphered. An effective and long-lasting therapeutic for globally increasing T1D patients has not been developed yet due to the knowledge voids in the pathophysiology of T1D. Specifically, researchers have been struggling to determine if β-cell destruction is caused by the immune system or is self-inflicted. In order to analyze this, pancreatic tissue blocks were sectioned to slides and stained with immunohistochemistry (IHC) and hematoxylin & eosin (H&E) stains to identify the spatial correlation between the islets and the nearby structures. However, IHC and H&E stains cannot be stained concurrently on the same slide of the tissue block, leading to the classic intra-slide variation problem. Therefore, this study utilized several deep generative models, including a new class of conditional diffusion models called Image-to-Image Schrödinger Bridge (I2SB), to virtually stain between IHC and H&E slides of the tissue block. Since most, if not all, of the previous virtual staining works utilized Generative Adversarial Networks (GANs), GANs and I2SB models were trained and evaluated in their ability to generate a virtual H&E image of high perceptual quality. By utilizing segmentation model-based and model-free evaluation methods, it was shown that a “conditional” variant of I2SB model, I2SB-cond, performed the best in the generation of virtual H&E images, but was not utilized due to its conditioned tissue map suffering from the intra-slide variation problem. The state-of-the-art GAN model for virtual staining and the vanilla I2SB model performed similarly, and was utilized to generate virtual WSIs, showing that these models can indeed be utilized to resolve the intra-slide variation problem. Lastly, the dominant performance of I2SB-cond model hints at its future potential for virtually staining the islets, or generation of virtual IHC images

Gravitational form factors of the baryon octet with flavor SU(3) symmetry breaking

We investigate the gravitational form factors of the baryon octet within the framework of the SU(3) chiral quark-soliton model, considering the effects of flavor SU(3) symmetry breaking, and the corresponding energy-momentum tensor distributions. We examine the effects of flavor SU(3) symmetry breaking to the mass, angular momentum, pressure, and shear force distributions of the baryon octet. We first find that a heavier baryon is energetically more compact than a lighter one. For the spin distributions of the baryon octet, they are properly normalized to their spins and are decomposed into the flavor-singlet axial charge and the orbital angular momentum even when the flavor SU(3) symmetry is broken. While the effects of the flavor SU(3) symmetry breaking differently contribute to the angular momentum distributions for the octet baryons, they are found to be rather small. The spin and orbital angular momentum almost equally contribute to the angular momentum distributions for the octet baryons. We also estimate the effects of the flavor SU(3) symmetry breaking to the pressure and shear force distributions. Interestingly, even if we include the effects of the SU(3) flavor symmetry breaking, the shear force distributions are kept to be positive over $r$. It indicates that the Polyakov & Schweitzer local stability condition is kept to be intact with the flavor SU(3) symmetry broken. Lastly, we discuss how much the gravitational form factors vary with the effects of flavor SU(3) symmetry breaking considered.Comment: 27 pages, 8 figure

Mechanical structure of the nucleon and the baryon octet: Twist-2 case

We investigate the gravitational form factors (GFFs) of the nucleon and the baryon octet, decomposed into their flavor components, utilizing a pion mean-field approach grounded in the large $N_c$ limit of Quantum Chromodynamics (QCD). Our focus is on the contributions from the twist-2 operators to the flavor-triplet and octet GFFs, and we decompose the mass, angular momentum, and $D$-term form factors of the nucleon into their respective flavors. The strange quark contributions are found to be relatively mild for the mass and angular momentum form factors, while providing significant corrections to the $D$-term form factor. In the course of examining the flavor decomposition of the GFFs, we uncover that the effects of twist-4 operators play a crucial role. While the gluonic contributions are suppressed by the packing fraction of the instanton vacuum in the twist-2 case, contributions from twist-4 operators are of order unity, necessitating its explicit consideration.Comment: 43 pages, 10 figure

Nucleon cosmological constant term and flavor structure of the gravitational form factors

The gravitational form factors furnish information on the mechanics of the nucleon. It is essential to compute the generalized isovector-vector form factors to examine the flavor structure of the gravitational form factors. The flavor-decomposed form factors reveal the internal structure of the nucleon. The up quark dominates over the down quark for the mass and spin of the nucleon, whereas the down quark takes over the up quark for the $D$-term form factor. We investigate for the first time the isovector cosmological constant term of the nucleon and its physical implications. The flavor-decomposed cosmological constant terms of the nucleon unveil how the up-quark contribution is exactly canceled by the down-quark contribution inside a nucleon within the framework of the pion mean-field approach. While the nucleon cosmological constant term does not contribute to the nucleon mass, its flavor structure sheds light on how the strong force fields due to the cosmological constant term characterize the stability of the nucleon.Comment: 7 pages and 4 figures. The text was improved and extende