Xi'an Jiaotong University

About: Xi'an Jiaotong University is a education organization based out in Xi'an, China. It is known for research contribution in the topics: Heat transfer & Dielectric. The organization has 85440 authors who have published 99682 publications receiving 1579683 citations. The organization is also known as: '''Xi'an Jiaotong University''' & Xi'an Jiao Tong University.

Camrelizumab in patients with previously treated advanced hepatocellular carcinoma: a multicentre, open-label, parallel-group, randomised, phase 2 trial

Abstract: Summary Background Blocking the interaction between PD-1 and its ligands is a promising treatment strategy for advanced hepatocellular carcinoma. This study aimed to assess the antitumour activity and safety of the anti-PD-1 inhibitor camrelizumab in pretreated patients with advanced hepatocellular carcinoma. Methods This is a multicentre, open-label, parallel-group, randomised, phase 2 trial done at 13 study sites in China. Eligible patients were aged 18 years and older with a histological or cytological diagnosis of advanced hepatocellular carcinoma, had progressed on or were intolerant to previous systemic treatment, and had an Eastern Cooperative Oncology Group performance score of 0–1. Patients were randomly assigned (1:1) to receive camrelizumab 3 mg/kg intravenously every 2 or 3 weeks, via a centralised interactive web-response system using block randomisation (block size of four). The primary endpoints were objective response (per blinded independent central review) and 6-month overall survival, in all randomly assigned patients who had at least one dose of study treatment. Safety was analysed in all treated patients. This study is registered with ClinicalTrials.gov , number NCT02989922 , and follow-up is ongoing, but enrolment is closed. Findings Between Nov 15, 2016, and Nov 16, 2017, 303 patients were screened for eligibility, of whom 220 eligible patients were randomly assigned and among whom 217 received camrelizumab (109 patients were given treatment every 2 weeks and 108 every 3 weeks). Median follow-up was 12·5 months (IQR 5·7–15·5). Objective response was reported in 32 (14·7%; 95% CI 10·3–20·2) of 217 patients. The overall survival probability at 6 months was 74·4% (95% CI 68·0–79·7)]. Grade 3 or 4 treatment-related adverse events occurred in 47 (22%) of 217 patients; the most common were increased aspartate aminotransferase (ten [5%]) and decreased neutrophil count (seven [3%]). Two deaths were judged by the investigators to be potentially treatment-related (one due to liver dysfunction and one due to multiple organ failure). Interpretation Camrelizumab showed antitumour activity in pretreated Chinese patients with advanced hepatocellular carcinoma, with manageable toxicities, and might represent a new treatment option for these patients. Funding Jiangsu Hengrui Medicine.

High-Energy-Density Dielectric Polymer Nanocomposites with Trilayered Architecture

Abstract: The development of advanced dielectric materials with high electric energy densities is of crucial importance in modern electronics and electric power systems. Here, a new class of multilayer-structured polymer nanocomposites with high energy and power densities is presented. The outer layers of the trilayered structure are composed of boron nitride nanosheets dispersed in poly(vinylidene fluoride) (PVDF) matrix to provide high breakdown strength, while PVDF with barium strontium titanate nanowires forms the central layer to offer high dielectric constant of the resulting composites. The influence of the filler contents on the electrical polarization, breakdown strength, and energy density is examined. Simulations are carried out to model the electrical tree formation in the layered nanocomposites and to verify the experimental breakdown results. The trilayered polymer nanocomposite with an optimized filler content displays a discharged energy density of 20.5 J cm−3 at Weibull breakdown strength of 588 MV m−1, which is among the highest discharged energy densities reported so far. Moreover, the nanocomposite exhibits a superior power density of 0.91 MW cm−3, more than nine times that of the commercially available biaxially oriented polypropylene. The findings of this research provide a new design paradigm for high-performance dielectric polymer nanocomposites.

High thermoelectric performance of oxyselenides: intrinsically low thermal conductivity of Ca-doped BiCuSeO

Abstract: We report on the high thermoelectric performance of p-type polycrystalline BiCuSeO, a layered oxyselenide composed of alternating conductive (Cu2Se2)2− and insulating (Bi2O2)2+ layers. The electrical transport properties of BiCuSeO materials can be significantly improved by substituting Bi3+ with Ca2+. The resulting materials exhibit a large positive Seebeck coefficient of ∼+330 μV K−1 at 300 K, which may be due to the ‘natural superlattice’ layered structure and the moderate effective mass suggested by both electronic density of states and carrier concentration calculations. After doping with Ca, enhanced electrical conductivity coupled with a moderate Seebeck coefficient leads to a power factor of ∼4.74 μW cm−1 K−2 at 923 K. Moreover, BiCuSeO shows very low thermal conductivity in the temperature range of 300 (∼0.9 W m−1 K−1) to 923 K (∼0.45 W m−1 K−1). Such low thermal conductivity values are most likely a result of the weak chemical bonds (Young’s modulus, E∼76.5 GPa) and the strong anharmonicity of the bonding arrangement (Gruneisen parameter, γ∼1.5). In addition to increasing the power factor, Ca doping reduces the thermal conductivity of the lattice, as confirmed by both experimental results and Callaway model calculations. The combination of optimized power factor and intrinsically low thermal conductivity results in a high ZT of ∼0.9 at 923 K for Bi0.925Ca0.075CuSeO. Li-Dong Zhao, Jiaqing He and co-workers have gained insight into the highly thermoelectric properties of a bismuth–copper oxyselenide (BiCuSeO), a polycrystalline, layered compound. BiCuSeO's ability to produce a significant electric potential from a temperature difference, and vice versa, arises from its intrinsically low thermal conductivity, and can be further improved by boosting the material's electrical conductivity through doping with strontium or barium, or introducing copper deficiencies. The researchers have now carried out an extensive characterization of the oxyselenide and propose that its conveniently low thermal conductivity results from the weak chemical bonds that exist between two different kinds of layers, and a particular bonding arrangement, in the material's lattice. Moreover, by substituting bismuth ions (Bi3+) with calcium ions (Ca3+) the thermal conductivity of the lattice could be lowered further, leading to an improvement in the oxyselenide's thermoelectric properties. We report on the promising thermoelectric performance of p-type polycrystalline BiCuSeO, which is a layered oxyselenide composed of conductive (Cu2Se2)2− layers that alternate with insulating (Bi2O2)2+ layers. Electrical transport properties can be optimized by substituting Bi3+ with Ca2+. Moreover, BiCuSeO shows very low thermal conductivity in the temperature ranges of 300 (∼0.9 W m−1K−1) to 923 K (∼0.45 W m−1 K−1). These intrinsically low thermal conductivity values may result from the weak chemical bonds of the material as well as the strong anharmonicity of the bonding arrangement. The combination of the optimized power factor and the intrinsically low thermal conductivity results in a high ZT of ∼0.9 at 923 K for Bi0.925Ca0.075CuSeO.