Unrevealing hardening and strengthening mechanisms in high-entropy ceramics from lattice distortion

Revealing the hardening and strengthening mechanisms is crucial for facilitating the design of superhard and high-strength high-entropy ceramics (HECs). Here, we take high-entropy diborides (HEB$_2$) as the prototype to thoroughly investigate the hardening and strengthening mechanisms of HECs. Specifically, the equiatomic 4- to 9-cation single-phase HEB$_2$ ceramics (4-9HEB$_2$) are fabricated by an ultra-fast high-temperature sintering method. The as-fabricated 4-9HEB$_2$ samples possess similar grain sizes, comparable relative densities (up to ~98%), uniform compositions, and clean grain boundaries without any impurities. The experimental results show that the hardness and flexural strength of the as-fabricated 4-9HEB$_2$ samples have an increasing tendency with the increase of metal components. The first-principles calculations find that lattice distortion is essential to the hardness and strength of HEB$_2$. With the increase of metal components, an aggravation of lattice distortion accompanied by B-B bond strengthening is determined, resulting in the enhancement of the hardness and flexural strength. Moreover, the correlation between other potential indicators and the hardness/flexural strength of HEB$_2$ has been disproved, including valence electron concentration, electronegativity mismatch, and metallic states. Our results unravel the hardening and strengthening mechanisms of HECs by intensifying lattice distortion, which may provide guidance for developing superhard and high-strength HECs

Case report: Chronic lymphocytic leukemia/small lymphocytic lymphoma and monomorphic epitheliotropic intestinal T-cell lymphoma: A composite lymphoma

Background: Composite lymphomas involving B-cell and T-cell lymphomas is very rare.Case presentation: We reported a 63-year-old gentleman with composite chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) and monomorphic epitheliotropic intestinal T-cell lymphoma (MEITL). The patient was admitted to our hospital due to abdominal pain, and was diagnosed with CLL/SLL after bone marrow (BM) biopsy, BM aspiration, and flow cytometry. Two weeks later, he was diagnosed with MEITL based on pathological analysis after intestine excision. Next gene sequencing (NGS) findings identified two hotspot mutation sites (STAT5B and DNMT3A) closely related with the pathogenesis of CLL/SLL and MEILT. Additionally, BCOR mutation was only detected in the CLL/SLL area. The likely pathogenic mutations of CLL were SETD2, NOTCH1, SF3B1, and PTPN11, while the likely pathogenic mutations related with the MEILT were TET2 and ZRSR2. Mutations of GATA3, PLCG2, and FAT1 were identified in both CLL/SLL and MEITL areas, but the clinical significance was unknown. Finally, the patient died in the 12-month follow-up after surgery.Conclusion: We report a rare case of composite CLL/SLL and MEITL that highlights the importance of careful inspection of hematologic neoplasms. We also present the results of NGS of different gene mutations in CLL and MEITL tissues

Mechanisms of inflammation after ischemic stroke in brain-peripheral crosstalk

Stroke is a devastating disease with high morbidity, disability, and mortality, among which ischemic stroke is more common. However, there is still a lack of effective methods to improve the prognosis and reduce the incidence of its complications. At present, there is evidence that peripheral organs are involved in the inflammatory response after stroke. Moreover, the interaction between central and peripheral inflammation includes the activation of resident and peripheral immune cells, as well as the activation of inflammation-related signaling pathways, which all play an important role in the pathophysiology of stroke. In this review, we discuss the mechanisms of inflammatory response after ischemic stroke, as well as the interactions through circulatory pathways between peripheral organs (such as the gut, heart, lung and spleen) and the brain to mediate and regulate inflammation after ischemic stroke. We also propose the potential role of meningeal lymphatic vessels (MLVs)-cervical lymph nodes (CLNs) as a brain-peripheral crosstalk lymphatic pathway in ischemic stroke. In addition, we also summarize the mechanisms of anti-inflammatory drugs in the treatment of ischemic stroke

YeastWeb: a workset-centric web resource for gene family analysis in yeast

<p>Abstract</p> <p>Background</p> <p>Currently, a number of yeast genomes with different physiological features have been sequenced and annotated, which provides invaluable information to investigate yeast genetics, evolutionary mechanism, structure and function of gene families.</p> <p>Description</p> <p>YeastWeb is a novel database created to provide access to gene families derived from the available yeast genomes by assigning the genes into putative families. It has many useful features that complement existing databases, such as SGD, CYGD and Génolevures: 1) Detailed computational annotation was conducted with each entry with InterProScan, EMBOSS and functional/pathway databases, such as GO, COG and KEGG; 2) A well established user-friendly environment was created to allow users to retrieve the annotated genes and gene families using functional classification browser, keyword search or similarity-based search; 3) Workset offers users many powerful functions to manage the retrieved data efficiently, associate the individual items easily and save the intermediate results conveniently; 4) A series of comparative genomics and molecular evolution analysis tools are neatly implemented to allow users to view multiple sequence alignments and phylogenetic tree of gene families. At present, YeastWeb holds the gene families clustered from various MCL inflation values from a total of 13 available yeast genomes.</p> <p>Conclusions</p> <p>Given the great interest in yeast research, YeastWeb has the potential to become a useful resource for the scientific community of yeast biologists and related researchers investigating the evolutionary relationship of yeast gene families. YeastWeb is available at <url>http://centre.bioinformatics.zj.cn/Yeast/</url>.</p

Quantum critical point in SmO1−xFxFeAs and oxygen vacancy induced by high fluorine dopant

The local lattice and electronic structure of the high-T(c) superconductor SmO(1-x)F(x)FeAs as a function of F-doping have been investigated by Sm L(3)-edge X-ray absorption near-edge structure and multiple-scattering calculations. Experiments performed at the L(3)-edge show that the white line (WL) is very sensitive to F-doping. In the under-doped region (x ≤ 0.12) the WL intensity increases with doping and then it suddenly starts decreasing at x = 0.15. Meanwhile, the trend of the WL linewidth versus F-doping levels is just contrary to that of the intensity. The phenomenon is almost coincident with the quantum critical point occurring in SmO(1-x)F(x)FeAs at x ≃ 0.14. In the under-doped region the increase of the intensity is related to the localization of Sm-5d states, while theoretical calculations show that both the decreasing intensity and the consequent broadening of linewidth at high F-doping are associated with the content and distribution of oxygen vacancies

Correlation between local vibrations and metal mass in AlB2-type transition-metal diborides

Lattice vibrations have been investigated in TiB2, ZrB2 and HfB2 by temperature-dependent extended X-ray absorption fine structure (EXAFS) experiments. Data clearly show that the EXAFS oscillations are characterized by an anomalous behavior of the Debye-Waller factor of the transition-metal-boron pair, which is suggested to be associated with a superposition of an optical mode corresponding to phonon vibrations induced by the B sublattice and an acoustic mode corresponding to the transition-metal (TM) sublattice. Data can be interpreted as a decoupling of the metal and boron vibrations observed in these transition-metal diborides (TMB2), a mechanism that may be responsible for the significant reduction of the superconducting transition temperature observed in these systems with respect to the parent MgB2 compound. The vibrational behavior of TM-TM bonds has also been investigated to study the occurrence of anisotropy and anomalies in the lattice vibrational behavior of TM-TM bonds