Accumulation and depletion layer thicknesses in organic field effect transistors

We present a simple but powerful method to determine the thicknesses of the accumulation and depletion layers and the distribution curve of injected carriers in organic field effect transistors. The conductivity of organic semiconductors in thin film transistors was measured in-situ and continuously with a bottom contact configuration, as a function of film thickness at various gate voltages. Using this method, the thicknesses of the accumulation and depletion layers of pentacene were determined to be 0.9 nm (VG=-15 V) and 5 nm (VG=15 V).Comment: 3 pages, 4 figures, Jap. J. Appl. Phys. in pres

Electric field induced charge injection or exhaustion in organic thin film transistor

The conductivity of organic semiconductors is measured {\it in-situ} and continuously with a bottom contact configuration, as a function of film thickness at various gate voltages. The depletion layer thickness can be directly determined as a shift of the threshold thickness at which electric current began to flow. The {\it in-situ} and continuous measurement can also determine qualitatively the accumulation layer thickness together with the distribution function of injected carriers. The accumulation layer thickness is a few mono layers, and it does not depend on gate voltages, rather depends on the chemical species.Comment: 4 figures, to be published in Phys. Rev.

Magnetic properties of epitaxial Fe3_3O4_4 films with various crystal orientations and TMR effect in room temperature

Fe$_3$O$_4$ is a ferrimagnetic spinel ferrite that exhibits electric conductivity at room temperature (RT). Although the material has been predicted to be a half metal according to ab-initio calculations, magnetic tunnel junctions (MTJs) with Fe$_3$O$_4$ electrodes have demonstrated a small tunnel magnetoresistance effect. Not even the sign of the TMR ratio has been experimentally established. Here, we report on the magnetic properties of epitaxial Fe$_3$O$_4$ films with various crystal orientations. The films exhibited apparent crystal orientation dependence on hysteresis curves. In particular, Fe$_3$O$_4$(110) films exhibited in-plane uniaxial magnetic anisotropy. With respect to the squareness of hysteresis, Fe$_3$O$_4$ (111) demonstrated the largest squareness. Furthermore, we fabricated MTJs with Fe$_3$O$_4$(110) electrodes, and obtained an TMR effect of -12\% at RT. The negative TMR ratio corresponded to the negative spin polarization of Fe$_3$O$_4$ predicted from band calculations

Computed tomography texture analysis for the prediction of lateral pelvic lymph node metastasis of rectal cancer

Background: This study aimed to investigate the usefulness of computed tomography (CT) texture analysis in the diagnosis of lateral pelvic lymph node (LPLN) metastasis of rectal cancer. Methods: This was a retrospective cohort study of 45 patients with rectal cancer who underwent surgery with LPLN dissection at Tokushima University Hospital from January 2017 to December 2021. The texture analysis of the LPLNs was performed on preoperative CT images, and 18 parameters were calculated. The correlation between each parameter and pathological LPLN metastasis was evaluated. The texture parameters were compared between pathologically metastasis-positive LPLNs and metastasis-negative LPLNs. Results: A total of 40 LPLNs were extracted from 25 patients by preoperative CT scans. No LPLNs could be identified in the remaining 19 patients. Eight of the 25 patients had pathologically positive LPLN metastasis. Extracted LPLNs were analyzed by the texture analysis. Pathologically metastasis-positive LPLNs had significantly lower mean Hounsfield unit, gray-level co-occurrence matrix (GLCM) energy, and GLCM Entropy_log2 values, and a significantly larger volume than pathologically metastasis-negative LPLNs. Multivariate analysis revealed that the independent predictive factors for LPLN metastasis were volume (a conventional parameter) (odds ratio 7.81, 95% confidence interval 1.42–43.1, p value 0.018) and GLCM Entropy_log2 (a texture parameter) (odds ratio 12.7, 95% confidence interval 1.28–126.0, p value 0.030). The combination of both parameters improved the diagnostic specificity while maintaining the sensitivity compared with each parameter alone. Conclusion: Combining the CT texture analysis with conventional diagnostic imaging may increase the accuracy of the diagnosis of LPLN metastasis of rectal cancer

Neutrophil-lymphocyte ratio in sleeve gastrectomy

Purpose : The aim was to investigate the impact of the neutrophil-lymphocyte ratio (NLR) in sleeve gastrectomy (SG). Methods : 15 obese patients were enrolled in this study ; mean body weight (BW) 127.5kg ; mean body mass index (BMI) 46.7kg / m2. 10 of these were diabetics who underwent a SG. The impact of the pre-operative NLR on the percentage of excess weight loss (%EWL) and remission of diabetes 1 year post-operative were examined. Results : The %EWL at 1 year post-operative were 46.3%. Improvements were also evident in the diabetes at 1 year post-operative : complete remission (CR) 40%, partial remission (PR) 20% and Improve 40%. Comparing pre-operative NLR in %EWL < 50% and ≧ 50% in 1 year post-operative, < 50% was 2.64 and ≧ 50% was 2.03. The NLR in CR and PR was significantly lower than that in Improve. Conclusions : The pre-operative NLR may be a predictive marker of weight loss and improving diabetes after SG

Improved Survival With Higher-risk Donor Grafts in Liver Transplant With Acute-on-chronic Liver Failure

Use of higher-risk grafts in liver transplantation for patients with acute-on-chronic liver failure (ACLF) has been associated with poor outcomes. This study analyzes trends in liver transplantation outcomes for ACLF over time based on the donor risk index (DRI). Methods: Using the Organ Procurement and Transplantation Network and the United Network for Organ Sharing registry, 17 300 ACLF patients who underwent liver transplantation between 2002 and 2019 were evaluated. Based on DRI, adjusted hazard ratios for 1-y patient death were analyzed in 3 eras: Era 1 (2002-2007, n = 4032), Era 2 (2008-2013, n = 6130), and Era 3 (2014-2019, n = 7138). DRI groups were defined by DRI2.0. Results: ACLF patients had significantly lower risks of patient death within 1 y in Era 2 (adjusted hazard ratio, 0.69; 95% confidence interval, 0.61-0.78; P \u3c 0.001) and Era 3 (adjusted hazard ratio, 0.48; 95% confidence interval, 0.42-0.55; P \u3c 0.001) than in Era 1. All DRI groups showed lower hazards in Era 3 than in Era 1. Improvement of posttransplant outcomes were found both in ACLF-1/2 and ACLF-3 patients. In ACLF-1/2, DRI 1.2 to 1.6 and \u3e2.0 had lower adjusted risk in Era 3 than in Era 1. In ACLF-3, DRI 1.2 to 2.0 had lower risk in Era 3. In the overall ACLF cohort, the 2 categories with DRI \u3e1.6 had significantly higher adjusted risks of 1-y patient death than DRI \u3c1.2. When analyzing hazards in each era, DRI \u3e 2.0 carried significantly higher adjusted risks in Eras 1 and 3\u27 whereas DRI 1.2 to 2.0 had similar adjusted risks throughout eras. Similar tendency was found in ACLF-1/2. In the non-ACLF cohort, steady improvement of posttransplant outcomes was obtained in all DRI categories. Similar results were obtained when only hepatitis C virus-uninfected ACLF patients were evaluated. Conclusions: In ACLF patients, posttransplant outcomes have significantly improved, and outcomes with higher-risk organs have improved in all ACLF grades. These results might encourage the use of higher-risk donors in ACLF patients and provide improved access to transplant

BLUE LED FOR COLON CANCER AND CAFs

Irradiation with a specific wavelength of light using light‑emitting diodes (LEDs) has various effects on cells and organisms. Recently, the antitumor effects of visible blue light on tumor cells were reported; however, the mechanism and effects on the tumor microenvironment remain unclear. Human colon cancer cells (HCT‑116) were injected into the rectal wall of nude mice. Tumors were irradiated with a 465‑nm LED light at 30 mW/cm2 for 30 min. Tumor volumes and the expression levels of opsin 3 (Opn3), autophagy‑related factors, cancer‑associated fibroblast (CAF) markers, and programmed cell death 1‑ligand (PD‑L1) were measured. Additionally, human intestinal fibroblasts were cultured in HCT116‑conditioned medium (CM) to prepare CAFs. CAFs were divided into an LED group and a control group, and the effect of the LED light on CAF activation in colon cancer cells was examined. Irradiation with blue LED light suppressed tumor growth; Opn3 expression was localized to the cell membrane in the LED group. Irradiated tumors exhibited increased autophagy‑related gene expression. Furthermore, in the LED group, TGF‑β and α‑SMA expression levels in the fibroblasts were decreased. Regarding CAFs, α‑SMA and IL‑6 expression levels were decreased in the LED group. HCT‑116 cells cultured in CAF‑CM with LED irradiation showed no enhanced migration or invasion. In the HCT‑116 cells cultured in CM of CAFs irradiated with LED, the relative increase in PD‑L1 expression was lower than that noted in the CAF‑CM without LED irradiation. Blue LED light may have a direct antitumor effect on colon cancer and also an inhibitory effect on CAFs