Strain Engineering of Ni-Rich Cathode Enables Exceptional Cyclability in Pouch-Type Full Cells

Ni-rich layered oxides are at the forefront of the development of high-energy Li-ion batteries, yet the extensive applications are retarded by the deteriorative capacity and thermal instability. Herein, an in situ co-precipitation strategy is implemented to achieve the novel super-dispersed Nb-doped Ni-rich cathode that consists of the elongated and radially aligned primary particles with increased oxygen stable {001} planes. The unique microstructure homogenizes the intragranular and intergranular strain distribution and stabilizes the spherical secondary particles, effectively inhibiting microcrack formation and propagation and surface degradation. The super-dispersed Nb doping prevents the Li/Ni disordering and lattice oxygen escape, thereby further strengthening the crystal structure and thermal stability. Accordingly, this cathode delivers a high reversible capacity of 229.0 mAh g^-1 at 0.1 C with much better retention at 55 °C and 5 C after 100 cycles than the conventional Nb-doped Ni-rich cathodes. In a pouch-type full cell, it exhibits exceptionally long life with a capacity retention of 91.9% at 1 C after 500 cycles and 80.5% at 5 C after 2000 cycles within 3.0-4.2 V, greatly prolonging the service period to cater to the lightweight and intelligence of electric vehicles.

Dynamics and Predictability of Tropical Cyclone Rapid Intensification in Ensemble Simulations of Hurricane Patricia (2015)

Hurricane Patricia (2015) over the eastern Pacific was a record-breaking tropical cyclone (TC) under a very favorable environment during its rapid intensification (RI) period, which makes it an optimal real case for studying RI dynamics and predictability. In this study, we performed ensemble Kalman filter analyses at Patricia's early development stage using both traditional observations and the Office of Naval Research Tropical Cyclone Intensity (TCI) field campaign data. It is shown that assimilating the inner-core TCI observations produces a stronger initial vortex and significantly improves the prediction of RI. Analysis of observation sensitivity experiments shows that the deep-layer dropsonde observations have high impact on both the primary and secondary circulations for the entire troposphere while the radar observations have the most impact on the primary circulations near aircraft flight level. A wide range of intensification scenarios are obtained through two sets of ensemble forecasts initialized with and without assimilating the TCI data prior to the RI onset. Verification of the ensemble forecasts against the TCI observations during the RI period shows that forecast errors toward later stages can originate from two different error sources at early stages of the vortex structure: One is a timing error from a delayed vortex development such that the TC evolution is the same but shifted in time; the other is due to a totally different storm such that there is no moment in time the simulated storm can obtain a correct TC structure.

Evolution and Regulation of Radial Structure of PAN Pre-Oxidized Fiber Based on the Fine Denier Model

Affected by ambient oxygen and thermal diffusion mechanism, the radial structural distribution of polyacrylonitrile (PAN) fiber during the pre-oxidation process will be inherited to the carbon fiber, which had a remarkable effect on the mechanical properties of carbon fiber. It is important to understand the evolution mechanism of radial structure evolution of PAN fiber during the pre-oxidation process to manufacture the high-performance carbon fiber. In this paper, a series of fine denier model fibers were prepared by adjusting the oxygen concentration to describe the structural characteristics at different radial regions of pre-oxidized fibers. The evolution mechanism of the radial structure of pre-oxidized fiber, with the increase of heat treatment temperature, was studied by the methods of optical microscope, C¹³ nuclear magnetic resonance (¹³C-NMR), and thermogravimetric analyzer (TGA). The results showed that along the radial direction of pre-oxidized fiber from skin to core layer, the degree of cyclization changed little while the dehydrogenation and oxygen-containing structure gradually decreased. Specifically, the oxygen-containing functional groups in the core decreased to the lowest level or even disappeared. A moderate increase of temperature in the initial and middle pre-oxidation processes could effectively promote the formation of cyclized structure and stabilize cross-linked ladder structure in the skin region of the fiber. With it, the thermal stability of obtained pre-oxidation fiber was improved.

Incidence of Fanconi anaemia in phenotypically normal aplastic anaemia patients in West Bengal

OBJECTIVES

Fanconi anaemia (FA) is a rare inherited bone marrow failure and autosomal recessive blood disorder. FA patients have a higher risk of cancer, including acute myeloid leukaemia and squamous cell carcinoma. Maximum, but not all, affected individuals have one or more somatic abnormalities, including skin, skeletal, genitourinary, gastrointestinal, cardiac and neurological anomalies, etc. Positive stress cytogenetics has immense implications for the treatment and management of FA. The aim of our study was to find out the incidence of FA in the population of phenotypically normal aplastic anaemia (AA) patients in West Bengal.

METHODS

Ethical clearances were obtained from the corresponding institutional committees. A total of 117 AA cases was selected. Stress cytogenetics was performed from peripheral venous blood (PVB) samples of 63 AA patients (age ≤ 50 years) and 63 age- and sex-matched healthy individual (control) using Mitomycin C (MMC).

RESULTS

Out of 63 AA patients, 6 (9.25%) cases showed positive stress cytogenetics suggestive of FA, which is statistically significant (p-value - 0.000532), analysed by chi-square test.

DISCUSSION

A considerable percentage of patients showing sensitivity towards MMC, even if they are phenotypically normal and did not have any distinguishable features which are generally found in FA.

CONCLUSION

This observation may indicate that stress cytogenetics analysis of phenotypically normal AA patients (≤50 years) is essential for the improvement of the treatment procedure.

Radial Structure Scaffolds Convolution Patterns of Developing Cerebral Cortex

Commonly-preserved radial convolution is a prominent characteristic of the mammalian cerebral cortex. Endeavors from multiple disciplines have been devoted for decades to explore the causes for this enigmatic structure. However, the underlying mechanisms that lead to consistent cortical convolution patterns still remain poorly understood. In this work, inspired by prior studies, we propose and evaluate a plausible theory that radial convolution during the early development of the brain is sculptured by radial structures consisting of radial glial cells (RGCs) and maturing axons. Specifically, the regionally heterogeneous development and distribution of RGCs controlled by Trnp1 regulate the convex and concave convolution patterns (gyri and sulci) in the radial direction, while the interplay of RGCs' effects on convolution and axons regulates the convex (gyral) convolution patterns. This theory is assessed by observations and measurements in literature from multiple disciplines such as neurobiology, genetics, biomechanics, etc., at multiple scales to date. Particularly, this theory is further validated by multimodal imaging data analysis and computational simulations in this study. We offer a versatile and descriptive study model that can provide reasonable explanations of observations, experiments, and simulations of the characteristic mammalian cortical folding.