Ballistic Thermal Rectification in Asymmetric Three-Terminal Mesoscopic Dielectric Systems

By coupling the asymmetric three-terminal mesoscopic dielectric system with a temperature probe, at low temperature, the ballistic heat flux flow through the other two asymmetric terminals in the nonlinear response regime is studied based on the Landauer formulation of transport theory. The thermal rectification is attained at the quantum regime. It is a purely quantum effect and is determined by the dependence of the ratio $\tau_{RC}(\omega)/\tau_{RL}(\omega)$ on $\omega$, the phonon's frequency. Where $\tau_{RC}(\omega)$ and $\tau_{RL}(\omega)$ are respectively the transmission coefficients from two asymmetric terminals to the temperature probe, which are determined by the inelastic scattering of ballistic phonons in the temperature probe. Our results are confirmed by extensive numerical simulations.Comment: 10 pages, 4 figure

IM3D: A parallel Monte Carlo code for efficient simulations of primary radiation displacements and damage in 3D geometry

SRIM-like codes have limitations in describing general 3D geometries, for modeling radiation displacements and damage in nanostructured materials. A universal, computationally efficient and massively parallel 3D Monte Carlo code, IM3D, has been developed with excellent parallel scaling performance. IM3D is based on fast indexing of scattering integrals and the SRIM stopping power database, and allows the user a choice of Constructive Solid Geometry (CSG) or Finite Element Triangle Mesh (FETM) method for constructing 3D shapes and microstructures. For 2D films and multilayers, IM3D perfectly reproduces SRIM results, and can be ∼10[superscript 2] times faster in serial execution and > 10[superscript 4] times faster using parallel computation. For 3D problems, it provides a fast approach for analyzing the spatial distributions of primary displacements and defect generation under ion irradiation. Herein we also provide a detailed discussion of our open-source collision cascade physics engine, revealing the true meaning and limitations of the “Quick Kinchin-Pease” and “Full Cascades” options. The issues of femtosecond to picosecond timescales in defining displacement versus damage, the limitation of the displacements per atom (DPA) unit in quantifying radiation damage (such as inadequacy in quantifying degree of chemical mixing), are discussed.National Natural Science Foundation (China) (Grant 11275229)National Natural Science Foundation (China) (Grant 11475215)National Natural Science Foundation (China) (Grant NSAF U1230202)National Natural Science Foundation (China) (Grant 11534012)National Basic Research Program of China (973 Program) (Grant 2012CB933702)Hefei Center for Physical Science and Technology (Grant 2012FXZY004)Chinese Academy of Sciences (Hefei Institutes of Physical Science (CASHIPS) Director Grant)National Science Foundation (U.S.) (DMR-1410636)National Science Foundation (U.S.) (DMR-1120901

A study on cotton yield prediction based on the chlorophyll fluorescence parameters of upper leaves

The early and accurate monitoring of crop yield is important for field management, storage needs, and cash flow budgeting. Traditional cotton yield measurement methods are time-consuming, labor-intensive, and subjective. Chlorophyll fluorescence signals originate from within the plant and have the advantages of being fast and non-destructive, and the relevant parameters can reflect the intrinsic physiological characteristics of the plant. Therefore, in this study, the top four functional leaves of cotton plants at the beginning of the flocculation stage were used to investigate the pattern of the response of chlorophyll fluorescence parameters (e.g., F0, Fm, Fv/F0, and Fv/Fm) to nitrogen, and the cumulative fluorescence parameters were constructed by combining them with the leaf area index to clarify the correlation between chlorophyll fluorescence parameters and cotton yield. Support vector machine regression (SVM), an artificial neural network (BP), and an XGBoost regression tree were used to establish a cotton yield prediction model. Chlorophyll fluorescence parameters showed the same performance as photosynthetic parameters, which decreased as leaf position decreased. It showed a trend of increasing and then decreasing with increasing N application level, reaching the maximum value at 240 kg·hm-2 of N application. The correlation between fluorescence parameters and yield in the first, second, and third leaves was significantly higher than that in the fourth leaf, and the correlation between fluorescence accumulation and yield in each leaf was significantly higher than that of the fluorescence parameters, with the best performance of Fv/Fm accumulation found in the second leaf. The correlation between Fv/Fm accumulation and yield in the top three leaves combined was significantly higher than that in the top four leaves. The correlation coefficient between Fv/Fm accumulation and yield was the highest, indicating the feasibility of applying chlorophyll fluorescence to estimate yield. Based on the machine learning algorithm used to construct a cotton yield prediction model, the estimation models of Fv/F0 accumulation and yield of the top two leaves combined as well as top three leaves combined were superior. The estimation model coefficient of determination of the top two leaves combined in the BP algorithm was the highest. In general, the Fv/F0 accumulation of the top two leaves combined could more reliably predict cotton yield, which could provide technical support for cotton growth monitoring and precision management

Cross-domain Transfer Learning and State Inference for Soft Robots via a Semi-supervised Sequential Variational Bayes Framework

Recently, data-driven models such as deep neural networks have shown to be promising tools for modelling and state inference in soft robots. However, voluminous amounts of data are necessary for deep models to perform effectively, which requires exhaustive and quality data collection, particularly of state labels. Consequently, obtaining labelled state data for soft robotic systems is challenged for various reasons, including difficulty in the sensorization of soft robots and the inconvenience of collecting data in unstructured environments. To address this challenge, in this paper, we propose a semi-supervised sequential variational Bayes (DSVB) framework for transfer learning and state inference in soft robots with missing state labels on certain robot configurations. Considering that soft robots may exhibit distinct dynamics under different robot configurations, a feature space transfer strategy is also incorporated to promote the adaptation of latent features across multiple configurations. Unlike existing transfer learning approaches, our proposed DSVB employs a recurrent neural network to model the nonlinear dynamics and temporal coherence in soft robot data. The proposed framework is validated on multiple setup configurations of a pneumatic-based soft robot finger. Experimental results on four transfer scenarios demonstrate that DSVB performs effective transfer learning and accurate state inference amidst missing state labels. The data and code are available at https://github.com/shageenderan/DSVB.Comment: Accepted at the International Conference on Robotics and Automation (ICRA) 202

Case Report: Durable complete response of metastatic hepatocellular carcinoma with asymptomatic hyperamylasemia to combined immunotherapy of anti-cytotoxic T lymphocyte-associated antigen 4 plus anti-programmed cell death-1 antibodies

BackgroundCombined immunotherapy has shown promising results in the treatment of advanced HCC, whereas the priority population that would respond to the combined immunotherapy is still elusive. In addition, HCC with asymptomatic hyperamylasemia was not reported previously.Case presentationAn aged patient was diagnosed as HCC with BCLC stage C (bone metastasis). Notably, this patient showed asymptomatic hyperamylasemia. The patient was then enrolled in a trial evaluating combined immunotherapy of anti-PD-1 antibody sintilimab (IBI308) plus anti-CTLA-4 antibody (IBI310) in advanced HCC. After being treated with combined immunotherapy, this patient rapidly achieved complete response (CR) according to mRECIST criteria or immune partial response (iPR) according to iRECIST criteria and maintain the CR state for more than 12 months. Interestingly, serum levels of amylase and lipase in this patient were reduced after treatment.ConclusionWe reported, for the first time, a case of metastatic HCC with asymptomatic hyperamylasemia, and suggested that HCC patients with asymptomatic hyperamylasemia may benefit from combined immunotherapy of anti-CTLA-4 and PD-1 antibodies

The treatment effect of posterior lumbar fusion surgery on patients suffering from lumbar disc herniation concurrent with peroneal nerve paralysis

PurposeThe purpose of this study is to investigate the clinical effect of posterior lumbar fusion surgery on patients who suffer from lumbar disc herniation concurrent with peroneal nerve paralysis.MethodsThe patients suffering from peroneal nerve paralysis and undergoing posterior lumbar fusion surgery between January 2012 and December 2019 were retrospectively reviewed. The data of the identified patients were then collected and processed. All patients were followed up post-operatively after discharge from the hospital. The data was analyzed in terms of Oswestry disability index (ODI), visual analogue scale (VAS) score, and relative lower-limb muscle strength.ResultsA total of 87 patients (52 males and 35 females) aged 54 ± 11 years met the inclusion criteria for this study. These patients stayed in hospital for 16 ± 6 days and were followed up for 81 ± 24 months. Data analysis showed that muscle strength of the tibialis anterior and extensor digitorum significantly recovered at the last follow-up with a grade of 3 (median), compared to grade 0 at admission (p < 0.001). Furthermore, the median VAS score decreased to 1 at the last follow-up from 6 at admission (p < 0.001), and the ODI greatly improved with 10% (median) at the last follow-up, while it was 58% at admission (p < 0.001). The ODI improvement rate was 60% on average at the last follow-up. Multivariate regression analysis regarding the ODI and muscle strength improvement rates showed that advanced age was a risk factor for postoperative recovery.ConclusionsMost of the patients suffering from lumbar disc herniation concurrent with peroneal nerve paralysis can improve after undergoing posterior lumbar fusion surgery, but few can reach full recovery. Advanced age might be a risk factor that affects the prognosis of these patients after surgery

Taurocholate Induces Connective Tissue Growth Factor Expression in Hepatocytes Through ERK-YAP Signaling

Background/Aims: Cholestasis is characterized by intrahepatic accumulation of cytotoxic bile acids (BAs), ultimately leading to fibrosis and cirrhosis, but the precise role of BAs in cholestasis-induced liver fibrosis remains largely elusive. In this study, we investigated the role and the potential mechanisms of BAs during cholestasis in vivo and in vitro. Methods: The effect of BAs during cholestasis was studied in bile duct ligation (BDL) rat models in vivo. We performed immunohistochemistry, Western blotting, and quantitative RT-PCR to investigate the expression of connective tissue growth factor (CTGF/CCN2) in rat liver during cholestasis. The hepatic cell lines AML12 and BRL were stimulated with taurocholate (TC) and the level of CTGF/CCN2, and activation of ERK, Akt, p38 MAPK, JNK, YAP, and TGF-β/Smad signaling were examined using Western blotting. Next, to elucidate the mechanism underlying bile acid-induced CTGF/CCN2, we treated the cells with MEK1/2 inhibitor (U0126), YAP function inhibitor (verteporfin), p38 kinase inhibitor (SB203580), Akt inhibitor (MK2206), and small interfering RNA (siRNA) targeting mek1, erk, and yap in cooperation with TC. Besides, we confirmed the activation of these signaling pathways in BDL and sham rat livers by immunohistochemistry, Western blotting, and quantitative RT-PCR. Results: In this study, we confirmed that the expression of CTGF/CCN2 was increased in BDL-induced rodent cholestatic liver fibrosis. In addition, we showed that TC, the main component of BAs, enhanced the synthesis of CTGF/ CCN2 in AML12 and BRL hepatic cell lines. Moreover, we demonstrated that TC activated ERK, Akt, and YAP signaling in hepatocytes, but the precise roles of these signaling cascades in the expression of CTGF/CCN2 were different: TC-induced expression of CTGF/CCN2 was mediated by ERK-YAP signaling, whereas Akt signaling inhibited ERK signaling and YAP and subsequently the expression of CTGF/CCN2 in hepatocytes. Furthermore, YAP functioned as a downstream regulator of ERK signaling in TC-induced CTGF/CCN2 expression in hepatocytes. Conclusion: Our report provides evidence for the role of conjugated BAs in liver fibrosis and suggests that the production of CTGF/CCN2, induced by conjugated BAs via ERK-YAP axis activation, may be a therapeutic target in cholestasis-induced liver fibrosis