We screened the electronic records of 2,799 patients admitted in Tongji Hospital from January 10th to February 18th, 2020. There were 375 discharged patients including 201 survivors. We built a prognostic prediction model based on XGBoost machine learning algorithm and then tested 29 patients (included 3 patients from other hospital) who were cleared after February 19th. Results:The mean age of the 375 patients was 58.83 years old with 58.7% of males. Fever was the most common initial symptom (49.9%), followed by cough (13.9%), fatigue (3.7%), and dyspnea (2.1%). Our model identified three key clinical features, i.e., lactic dehydrogenase (LDH), lymphocyte and High-sensitivity C-reactive protein (hs-CRP), from a pool of more than 300 features. The clinical route is simple to check and can precisely and quickly assess the risk of death. Therefore, it is of great clinical significance. : medRxiv preprint Conclusion:The three indices-based prognostic prediction model we built is able to predict the mortality risk, and present a clinical route to the recognition of critical cases from severe cases. It can help doctors with early identification and intervention, thus potentially reducing mortality.

Solid-state dielectric energy storage is the most attractive and feasible way to store and release high power energy compared to chemical batteries and electrochemical super-capacitors.

A B S T R A C TDielectric capacitors are very attractive for high power energy storage. However, the low energy density of these capacitors, which is mainly limited by the dielectric materials, is still the bottleneck for their applications. In this work, lead-free single-phase perovskite Sr x (Bi 1−x Na 0.97−x Li 0.03 ) 0.5 TiO 3 (x = 0.30 and 0.38) bulk ceramics, prepared using solid-state reaction method, were carefully studied for the dielectric capacitor application. Polar nano regions (PNRs) were created in this material using co-substitution at A-site to enable relaxor behaviour with low remnant polarization (P r ) and high maximum polarization (P max ). Moreover, P max was further increased due to the electric field induced reversible phase transitions in nano regions. Comprehensive structural and electrical studies were performed to confirm the PNRs and reversible phase transitions. And finally a high energy density (1.70 J/cm 3 ) with an excellent efficiency (87.2%) was achieved using the contribution of field-induced rotations of PNRs and PNR-related reversible transitions in this material, making it among the best performing lead-free dielectric ceramic bulk material for high energy storage.

Ceramics of composition Ag1−3xBixNbO3 (0.005 ≤ x ≤ 0.040) were prepared by solid state methods and their structure and electrical behavior were characterized with a view to their potential use as high power energy storage materials.

0.94­(Bi0.5Na0.5TiO3)–0.06­(BaTiO3) (BNTBT) is a potential lead-free piezoelectric candidate to replace lead-based PZT ceramics. The thermal depoling temperature sets the upper limit for the high temperature application of piezoelectric materials. Recently, an interface model was proposed to explain the good resistance to thermal depoling of BNTBT-ZnO composite. However, we found that the presence of ZnO was not limited to the interface, but contributed intrinsically to the BNTBT lattice. This played a critical role in the structural changes of BNTBT, confirmed by a unit volume change supported by XRD, which was further proved by Raman, EDS, and dielectric characterization at different temperatures. The previous interface model is not correct because BNTBT shows thermally stable piezoelectric properties, even though there is no interface between BNTBT and ZnO. The thermal depoling behavior of BNTBT-based materials is directly related to the transition temperature from the rhombohedral phase to the tetragonal phase in our phase transition model, which is consistent with four current peaks in their ferroelectric loops close to the depoling temperature.