Evaluation of kidney allograft status using novel ultrasonic technologies

Early diagnosis of kidney allograft injury contributes to proper decisions regarding treatment strategy and promotes the long-term survival of both the recipients and the allografts. Although biopsy remains the gold standard, non-invasive methods of kidney allograft evaluation are required for clinical practice. Recently, novel ultrasonic technologies have been applied in the evaluation and diagnosis of kidney allograft status, including tissue elasticity quantification using acoustic radiation force impulse (ARFI) and contrast-enhanced ultrasonography (CEUS). In this review, we discuss current opinions on the application of ARFI and CEUS for evaluating kidney allograft function and their possible influencing factors, advantages and limitations. We also compare these two technologies with other non-invasive diagnostic methods, including nuclear medicine and radiology. While the role of novel non-invasive ultrasonic technologies in the assessment of kidney allografts requires further investigation, the use of such technologies remains highly promising

Optimizing evasive strategies for an evader with imperfect vision capacity

The multiagent pursuit-evasion problem has attracted considerable interest during recent years, and a general assumption is that the evader has perfect vision capacity. However, in the real world, the vision capacity of the evader is always imperfect, and it may have noisy observation within its limited field of view. Such an imperfect vision capacity makes the evader sense incomplete and inaccurate information from the environment, and thus, the evader will achieve suboptimal decisions. To address this challenge, we decompose this problem into two subproblems: 1) optimizing evasive strategies with a limited field of view, and 2) optimizing evasive strategies with noisy observation. For the evader with a limited field of view, we propose a memory-based ‘worst case’ algorithm, the idea of which is to store the locations of the pursuers seen before and estimate the possible region of the pursuers outside the sight of the evader. For the evader with noisy observation, we propose a value-based reinforcement learning algorithm that trains the evader offline and applies the learned strategy to the actual environment, aiming at reducing the impact of uncertainty created by inaccurate information. Furthermore, we combine and make a trade-off between the above two algorithms and propose a memory-based reinforcement learning algorithm that utilizes the estimated locations to modify the input of the state set in the reinforcement learning algorithm. Finally, we extensively evaluate our algorithms in simulation, concluding that in this imperfect vision capacity setting, our algorithms significantly improve the escape success rate of the evader.This work was supported by the National Natural Science Foundation of China (61472079, 61170164, 61807008 and 61806053), the Natural Science Foundation of Jiangsu Province of China (BK20171363, BK20180356, BK20180369, BK20170693)

Trifluoromethyl-Substituted Large Band-Gap Polytriphenylamines for Polymer Solar Cells with High Open-Circuit Voltages

Two large band-gap polymers (PTPACF and PTPA2CF) based on polytriphenylamine derivatives with the introduction of electron-withdrawing trifluoromethyl groups were designed and prepared by Suzuki polycondensation reaction. The chemical structures, thermal, optical and electrochemical properties were characterized in detail. From the UV-visible absorption spectra, the PTPACF and PTPA2CF showed the optical band gaps of 2.01 and 2.07 eV, respectively. The cyclic voltammetry (CV) measurement displayed the deep highest occupied molecular orbital (HOMO) energy levels of −5.33 and −5.38 eV for PTPACF and PTPA2CF, respectively. The hole mobilities, determined by field-effect transistor characterization, were 2.5 × 10−3 and 1.1 × 10−3 cm2 V−1 S−1 for PTPACF and PTPA2CF, respectively. The polymer solar cells (PSCs) were tested under the conventional device structure of ITO/PEDOT:PSS/polymer:PC71BM/PFN/Al. All of the PSCs showed the high open circuit voltages (Vocs) with the values approaching 1 V. The PTPACF and PTPA2CF based PSCs gave the power conversion efficiencies (PCEs) of 3.24% and 2.40%, respectively. Hence, it is a reliable methodology to develop high-performance large band-gap polymer donors with high Vocs through the feasible side-chain modification

A nano fiber–gel composite electrolyte with high Li+ transference number for application in quasi-solid batteries

As their Li+ transference number (tLi+), ionic conductivity, and safety are all high, polymer electrolytes play a vital role in overcoming uncontrollable lithium dendrites and low energy density in Li metal batteries (LMBs). We therefore synthesized a three-dimensional (3D) semi-interpenetrating network-based single-ion-conducting fiber–gel composite polymer electrolyte (FGCPE) via an electrospinning, initiation, and in situ polymerization method. The FGCPE provides high ionic conductivity (1.36 ​mS ​cm−1), high tLi+ (0.92), and a high electrochemical stability window (up to 4.84 ​V). More importantly, the aromatic heterocyclic structure of the biphenyl in the nanofiber membrane promotes the carbonization of the system (the limiting oxygen index value of the nanofiber membrane reaches 41%), giving it certain flame-retardant properties and solving the source-material safety issue. Due to the in situ method, the observable physical interface between electrodes and electrolytes is virtually eliminated, yielding a compact whole that facilitates rapid kinetic reactions in the cell. More excitingly, the LFP/FGCPE/Li cell displays outstanding cycling stability, with a capacity retention of 91.6% for 500 cycles even at 10C. We also test the FGCPE in high-voltage NMC532/FGCPE/Li cells and pouch cells. This newly designed FGCPE exhibits superior potential and feasibility for promoting the development of LMBs with high energy density and safety

The microstructure and mechanical properties of novel Fe-rich Fe–Cr–Ni–Ta eutectic multi-principal element alloys

Co–Cr–Fe–Ni–Ta eutectic multi-principal element alloys (MPEAs) demonstrate great potential to replace structural alloys in engineering applications. However, the cost of these alloys is high due to the usage of a number of precious metals. To decrease the cost, the present work developed a set of novel Fe55Cr15Ni30−xTax (x = 0, 5, 8, 10 and 15 at.%) eutectic MPEAs and the effect of Ta on microstructure and compressive mechanical properties were investigated for the first time. As the Ta content increases, the microstructure changes from a single-phase FCC solid solution (x = 0) to hypoeutectic microstructure (x = 6), then to eutectic microstructure (x = 8), and eventually to hypereutectic microstructure (x = 10 and 15). The yield strength and the hardness increase at the expense of ductility reduction with increasing Ta content. The strengthening mechanism of this alloy system is mainly second-phase strengthening caused by Laves phase and grain boundary strengthening produced by eutectic interface, supplemented by solid solution strengthening. The Fe55Cr15Ni22Ta8 and Fe55Cr15Ni20Ta10 alloys present the excellent comprehensive mechanical properties. The yield strength, fracture strength and fracture strain of the former are 838 MPa, 1994 MPa and 45.1%, respectively. The yield strength, fracture strength and fracture strain of the latter are 1029 MPa, 1956 MPa and 43.0%, respectively. The phase formation of Fe55Cr15Ni30−xTax alloys can be predicted by Md criterion. When Md ≥ 0.89, the alloys consist of FCC phase and Laves phase. Otherwise, the alloys consist of FCC single phase

Enhanced Mechanochemiluminescence from End-Functionalized Polyurethanes with Multiple Hydrogen Bonds

The chemiluminescent mechanophore, 1,2-dioxetane (Ad), is incorporated into the backbone of a polyurethane-based prepolymer, which is further end-capped with dimerizable strong hydrogen bonding units, ureidopyrimidinone and pyrimidinedione (UPy, DHB-2) or hydrogen bonding free unit (EtOH). Mechanical, optomechanical measurements, and small-angle/wide-angle X-ray scattering (SAXS/WAXS) analyses of these end-functionalized polyurethanes have demonstrated that the difference in the strength of hydrogen bonding interactions led to different degrees of chain orientation in the bulk, and consequently, different levels of mechano-activation of Ad with distinguishable mechanochemiluminescence intensity. This study not only offers a straightforward way to enhance the mechanochemiluminescence of Ad containing polymers by tailoring the supramolecular interactions between different macromers but also deepens our understanding of the correlations between chain orientation behavior, magnitudes of hydrogen bonding interactions, and the activation of mechanophores

Terpolymers Containing Difluorobenzoxadiazole Enable Suppressed Energy Losses and Optimal Batch-to-Batch Reproducibility for High-Efficiency Organics Solar Cells

Developing high-performance polymer donors is of great importance to further improve the photovoltaic performances of organic solar cells (OSCs). However, most polymer donors suffer from mismatching energy levels and poor batch-to-batch reproducibility, which hinder the further enhancement of device performance and their potential in a commercial application. Constructing random terpolymers with a third monomer is considered a practical way to solve these problems. Herein, the 5,6-difluorobenzo[c][1,2,5]oxadiazole (ffBX) unit is incorporated into the skeleton of PBDB-TF as the third comonomer to construct random terpolymers. The terpolymers exhibit downshifted the highest occupied molecular orbital energy levels than PBDB-TF, which is beneficial for obtaining higher open-circuit voltage and lower energy loss of the OSCs. The OSCs based on PBFBX20:Y6-BO demonstrate high power conversion efficiency of 17.5%. Moreover, PBFBX20 exhibits excellent batch-to-batch reproducibility. Five polymer batches with molecular weights ranging from 20.0 to 54.0 kDa produced very similar PCEs. This work demonstrates the bright future of ffBX-contained terpolymers in realizing high-performance OSCs and further applying in the OSCs community

An electron acceptor featuring a B-N covalent bond and small singlet-triplet gap for organic solar cells

BNTT2F, an electron acceptor featuring a B-N covalent bond and singlet-triplet gap as low as 0.20 eV via the multiple resonance effect, is developed for organic solar cells. The optimized device based on BNTT2F offered an efficiency of 8.3%, suggesting the great prospect of B-N covalent bond-containing π-conjugated molecules for photovoltaics

Epidemiology of Drug- and Herb-Induced Liver Injury Assessed for Causality Using the Updated RUCAM in Two Hospitals from China

Drug- and herb-induced liver injury (DILI and HILI) is an increasingly common and serious condition. Here, data for DILI and HILI patients from two large tertiary hospitals were retrospectively analyzed. Patient characteristics, causes and severity of DILI and HILI, the correlation between expression of p62 and the severity of DILI and HILI, treatment of DILI and HILI, and the prognostic factors of DILI and HILI were studied. A total of 82 patients with DILI and HILI were recruited for the study. Most patients presented with hepatocellular injury, followed by cholestatic injury and mixed injury. Our results indicate that traditional Chinese medicine or herbal and dietary supplements were the prevalent causal agents of HILI, which was characterized by higher frequencies of hepatocellular injury. Expression of p62 in the liver correlated with the severity of DILI and HILI. Improvements in the results of the liver enzymatic tests correlated with alanine transaminase (ALT) levels upon the first diagnosis of DILI and HILI and with the hepatocellular type of DILI and HILI. In conclusion, we provide an epidemiological assessment of DILI and HILI based on causality using the updated RUCAM on patients from two hospitals in China. ALT levels at first diagnosis and the hepatocellular type of injury may be prognostic factors of DILI and HILI