Chinese herb nephropathy contains a variety of clinical features of progressive renal failure (indicated by studies conducted in Belgium) to the variant type of Fanconi's syndrome. Fanconi's syndrome has mostly been reported in Asian countries, and is characterized by proximal tubular dysfunction and slower progression to end-stage renal disease (ESRD); it also often revealed a reversible clinical course. We describe a 43-year-old woman who presented with polyuria and polydipsia caused by Fanconi's syndrome. The cause of Fanconi's syndrome was not identified because the patient denied the intake of the Chinese herbal mixture at first. Fanconi's syndrome seemed to be reversible in its early stage, but it rapidly progressed to renal failure after 3 months, despite the interruption of Chinese mixture use. A renal biopsy revealed typical findings of aristolochic acid-induced nephropathy. Aristolochic acids were also detected in the Chinese herbs that were consumed. This case highlights the variety of the clinical spectrum of aristolochic acid induced nephropathy (AAN). We emphasize that AAN should be suspected in all patients with Fanconi's syndrome, even if patients deny the intake of any Chinese herbal preparation.
Bond characteristics, mechanical properties, and high‐temperature thermal conductivity of ultrahigh‐temperature ceramics (UHTCs), hafnium carbide (HfC), tantalum carbide (TaC), and their solid solution composites, were investigated using first‐principles calculations. Mulliken analyses revealed that Ta formed stronger covalent bonds with C than did Hf. Bond overlap analyses indicated that the Hf–C bond possessed mixed covalent and ionic bond characteristics, compared with the more covalent character of the Ta–C bond. Consequently, the overall elastic properties were enhanced with increasing number of Ta–C bonds in the composites. The overall metallicity of the composites also increased with increasing TaC content; thus, the mechanical properties did not improve monotonically. Our results indicate that adding a small amount of TaC to HfC or vice versa to produce a composite would create a new UHTC with greatly improved elastic and mechanical properties as well as high‐temperature thermal conductivity.
MXenes are an emerging class of 2D materials with unique properties including metallic conductivity, mechanical flexibility, and surface tunability, which ensure their utility for diverse applications. However, the synthesis of MXenes with high crystallinity and atomic stoichiometry in a low‐cost process is still challenging because of the difficulty in controlling the oxygen substitute in the precursors and final products of MXenes, which limits their academic understanding and practical applications. Here, a novel cost‐effective method is reported to synthesize a highly crystalline and stoichiometric Ti3C2Tx MXene with minimum substitutional oxygen impurities by controlling the amount of excess carbon and time of high‐energy milling in carbothermal reduction of recycled TiO2 source. The highest used content (2 wt%) of excess‐carbon yields TiC with the highest carbon content and minimal oxygen substitutes, which leads to the Ti3AlC2 MAX phase with improved crystallinity and atomic stoichiometry, and finally Ti3C2Tx MXene with the highest electrical conductivity (11738 S cm−1) and superior electromagnetic shielding effectiveness. Additionally, the effects of carbon content and substitutional oxygen on the physical properties of TiC and Ti3AlC2 are elucidated by density‐functional‐theory calculations. This inexpensive TiO2‐based method of synthesizing high‐quality Ti3C2Tx MXene can facilitate large‐scale production and thus accelerate global research on MXenes.
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